This document provides an overview of infrared spectroscopy and its application in analyzing organic compounds. It begins with background information on spectroscopy and infrared spectroscopy principles. It then discusses different molecular vibrations observed in infrared spectroscopy and factors that influence vibration frequencies. The document outlines instrumentation used in infrared spectroscopy and describes common functional groups observed in organic compounds, including hydrocarbons like alkanes, alkenes, and alkynes. It provides infrared absorption frequencies and examples of spectra for different compounds. The overall purpose is to educate students on using infrared spectroscopy to identify organic molecules based on their functional groups and absorption patterns.
Infrared spectroscopy is a technique that uses infrared light to analyze chemical bonding and molecular structure. It works by detecting the frequencies at which molecules vibrate or rotate when exposed to infrared radiation. The document discusses the principles of infrared spectroscopy, including how molecular vibrations can be excited when their frequency matches the frequency of infrared radiation. It also covers factors that determine infrared absorption frequencies and the types of molecular vibrations that are infrared active.
Infrared spectroscopy analyzes molecular vibrations induced by infrared light absorption. It provides information about functional groups present in molecules. There are two main types of vibrations - stretching and bending. Stretching vibrations involve changes in bond lengths and require higher energy, while bending vibrations involve changes in bond angles and require lower energy. IR spectroscopy is used to identify functional groups like alcohols, aldehydes, ketones, carboxylic acids, amines, amides, alkenes, alkynes, and nitriles based on their characteristic absorption bands.
Infrared spectroscopy (IR spectroscopy) is the spectroscopy that deals with the infrared
region of the electromagnetic spectrum, that is light with a longer wavelength and
lower frequency than visible light.
Infrared Spectroscopy is the analysis of infrared light interacting with a molecule.
UV-visible spectrophotometers have five main components: a light source, filters or monochromator, sample compartment, detector, and recorder. Common light sources include tungsten lamps for the visible region and deuterium lamps for the UV region. Filters and monochromators are used to select the wavelength of light. Samples are placed in the sample compartment for analysis. Detectors such as photodiodes, photomultiplier tubes, or barrier layer cells convert light signals to electrical signals. The signals are then recorded to obtain a spectrum.
The document discusses spectrofluorimetry and luminescence spectroscopy. It defines fluorescence and phosphorescence as types of photoluminescence that occur when a molecule absorbs radiation and then emits light as it relaxes to the ground state. Fluorescence emission occurs from the lowest excited singlet state on a timescale of 10-9 to 10-7 seconds, while phosphorescence emission occurs from the lowest triplet excited state on a longer timescale of 10-6 to 10 seconds. The document also provides examples of applications including the analysis of polyaromatic hydrocarbons like benzo(a)pyrene and fluorimetric drug analysis including the detection of LSD.
This document discusses double resonance in nuclear magnetic resonance (NMR) spectroscopy. It explains spin decoupling techniques that are used to simplify complex NMR spectra. By irradiating coupled protons, decoupling can eliminate splitting of signals and cause multiplets to collapse into doublets or singlets. This produces easier to interpret spectra. Decoupling is demonstrated on an ethanol sample, where exchanging hydrogens for deuterium causes signals to disappear. Irradiating methyl hydrogens in a molecule can also simplify signals by removing coupling to adjacent protons. Decoupling enhances spectral signals and allows clearer distinction between them.
IR spectroscopy analyzes the vibrational frequencies of bonds in molecules to determine their structure. It works by measuring the absorption of IR radiation by molecular bonds. Different functional groups absorb at characteristic frequencies, producing a molecular "fingerprint". IR spectroscopy is useful for identification of unknown compounds, analyzing purity, and monitoring chemical reactions through changes in bond absorption. It is a nondestructive technique applied in various fields such as pharmaceutical analysis, biomedical research, forensic science, and atmospheric studies.
This document discusses proton magnetic resonance spectroscopy (NMR spectroscopy), specifically focusing on spin-spin coupling, coupling constants, and the different types of coupling that can occur including geminal, vicinal, and long range coupling. It explains that the coupling constant value increases with increasing bond angle and electronegativity. It also discusses first order spectra and provides examples of geminal, vicinal, and long range coupling, as well as factors that affect coupling constant values.
Infrared spectroscopy is a technique that uses infrared light to analyze chemical bonding and molecular structure. It works by detecting the frequencies at which molecules vibrate or rotate when exposed to infrared radiation. The document discusses the principles of infrared spectroscopy, including how molecular vibrations can be excited when their frequency matches the frequency of infrared radiation. It also covers factors that determine infrared absorption frequencies and the types of molecular vibrations that are infrared active.
Infrared spectroscopy analyzes molecular vibrations induced by infrared light absorption. It provides information about functional groups present in molecules. There are two main types of vibrations - stretching and bending. Stretching vibrations involve changes in bond lengths and require higher energy, while bending vibrations involve changes in bond angles and require lower energy. IR spectroscopy is used to identify functional groups like alcohols, aldehydes, ketones, carboxylic acids, amines, amides, alkenes, alkynes, and nitriles based on their characteristic absorption bands.
Infrared spectroscopy (IR spectroscopy) is the spectroscopy that deals with the infrared
region of the electromagnetic spectrum, that is light with a longer wavelength and
lower frequency than visible light.
Infrared Spectroscopy is the analysis of infrared light interacting with a molecule.
UV-visible spectrophotometers have five main components: a light source, filters or monochromator, sample compartment, detector, and recorder. Common light sources include tungsten lamps for the visible region and deuterium lamps for the UV region. Filters and monochromators are used to select the wavelength of light. Samples are placed in the sample compartment for analysis. Detectors such as photodiodes, photomultiplier tubes, or barrier layer cells convert light signals to electrical signals. The signals are then recorded to obtain a spectrum.
The document discusses spectrofluorimetry and luminescence spectroscopy. It defines fluorescence and phosphorescence as types of photoluminescence that occur when a molecule absorbs radiation and then emits light as it relaxes to the ground state. Fluorescence emission occurs from the lowest excited singlet state on a timescale of 10-9 to 10-7 seconds, while phosphorescence emission occurs from the lowest triplet excited state on a longer timescale of 10-6 to 10 seconds. The document also provides examples of applications including the analysis of polyaromatic hydrocarbons like benzo(a)pyrene and fluorimetric drug analysis including the detection of LSD.
This document discusses double resonance in nuclear magnetic resonance (NMR) spectroscopy. It explains spin decoupling techniques that are used to simplify complex NMR spectra. By irradiating coupled protons, decoupling can eliminate splitting of signals and cause multiplets to collapse into doublets or singlets. This produces easier to interpret spectra. Decoupling is demonstrated on an ethanol sample, where exchanging hydrogens for deuterium causes signals to disappear. Irradiating methyl hydrogens in a molecule can also simplify signals by removing coupling to adjacent protons. Decoupling enhances spectral signals and allows clearer distinction between them.
IR spectroscopy analyzes the vibrational frequencies of bonds in molecules to determine their structure. It works by measuring the absorption of IR radiation by molecular bonds. Different functional groups absorb at characteristic frequencies, producing a molecular "fingerprint". IR spectroscopy is useful for identification of unknown compounds, analyzing purity, and monitoring chemical reactions through changes in bond absorption. It is a nondestructive technique applied in various fields such as pharmaceutical analysis, biomedical research, forensic science, and atmospheric studies.
This document discusses proton magnetic resonance spectroscopy (NMR spectroscopy), specifically focusing on spin-spin coupling, coupling constants, and the different types of coupling that can occur including geminal, vicinal, and long range coupling. It explains that the coupling constant value increases with increasing bond angle and electronegativity. It also discusses first order spectra and provides examples of geminal, vicinal, and long range coupling, as well as factors that affect coupling constant values.
The document discusses the applications of infrared (IR) spectroscopy for qualitative and quantitative analysis. IR spectroscopy can be used to identify functional groups and determine molecular structures. It allows study of hydrogen bonding, geometrical isomers, and reaction progress. Near IR is applied to agriculture and pharmaceutical analysis while mid IR identifies organic and biological species. Far IR is used in medical treatments and astronomy. In summary, IR spectroscopy enables structural analysis and has various applications across chemistry, biology, medicine, and astronomy.
There are four main techniques used to prepare solid samples for IR spectroscopy: dissolving solids in solution, solid films, mull technique, and pressed pellet technique. The mull technique involves grinding the solid sample with a mulling agent like mineral oil or nujol to form a paste between IR windows. The pressed pellet technique uses potassium bromide to form a compressed pellet, avoiding interference from a mulling agent. Liquids can be analyzed directly in liquid sample cells of appropriate thickness.
A method of obtaining an Infrared spectrum by measuring the interferogram of a sample using an interferometer, then performing a Fourier Transform upon the interferogram to obtain the spectrum.
2D NMR provides more information than 1D NMR by plotting data in a space defined by two frequency axes. There are several types of 2D NMR experiments including COSY, NOESY, and HETCOR. COSY identifies spin-coupled protons by showing cross peaks between protons that are directly bonded. NOESY correlates protons that are near each other in space but not necessarily directly bonded. HETCOR plots 1H and 13C spectra on separate axes and connects carbon signals to bonded proton signals. 2D NMR techniques provide additional structural information about molecules compared to traditional 1D NMR.
Infrared spectroscopy involves using infrared radiation to analyze materials. Molecules absorb specific infrared frequencies that are characteristic of their structure, such as bond vibrations and stretches. There are two main methods for infrared spectroscopy - scanning monochromator which analyzes one wavelength at a time, and Fourier transform infrared spectroscopy which uses interferometry to measure all infrared wavelengths simultaneously. Fourier transform then converts this raw interferogram data into the infrared spectrum. Infrared spectroscopy can be used to identify functional groups and molecular structures in compounds like 1-Hexene, Toluene, and Cyclohexanol based on their characteristic absorption peaks.
2D NMR techniques provide additional information beyond conventional 1D NMR. COSY identifies pairs of coupled protons, while HETCOR identifies the number of protons directly bonded to a particular carbon. NOESY and ROESY spectra locate protons that are close in space. DEPT distinguishes between carbon types such as CH3, CH2, CH, and quaternary carbons. Spin decoupling simplifies spectra by removing coupling between irradiated and non-irradiated protons.
Basics of Infrared Spectroscopy : Theory, principles and applicationsHemant Khandoliya
1. Spectroscopy involves using electromagnetic radiation to obtain information about atoms and molecules. Infrared (IR) spectroscopy specifically analyzes molecular vibrations that occur when IR radiation is absorbed.
2. IR spectroscopy is useful for structure elucidation and identification of organic compounds by determining their functional groups based on characteristic absorption bands. It can also be used to study reaction progress and detect impurities.
3. Factors like hydrogen bonding, coupling effects, and electronic effects can influence vibrational frequencies observed in IR spectra. Advanced applications include quantitative analysis, studying isomerism, and determining unknown contaminants.
Attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) is a technique where an infrared beam reflects off an internal reflection element and into a sample, generating an evanescent wave that penetrates into the sample. It requires little to no sample preparation and can analyze samples in less than a minute. The depth of penetration depends on factors like the wavelength and the refractive indexes of the sample and element. Common element materials include germanium, silicon, zinc selenide, and diamond. ATR-FTIR is useful for analyzing solids, liquids, powders and can characterize surface layers and opaque samples with limitations in sensitivity compared to transmission methods.
Infrared spectroscopy involves interaction of infrared radiation with matter. It covers absorption spectroscopy techniques and is conducted using an infrared spectrometer. The infrared region is divided into three regions based on wavelengths. Infrared spectroscopy follows Beer's law and analyzes the selective absorption bands in a sample's infrared spectrum to determine its molecular structure and identify functional groups, compounds, and impurities. It has applications in analyzing organic and inorganic compounds.
This document provides an overview of infrared spectroscopy. It discusses the principle that infrared spectroscopy involves absorption of infrared radiation which causes vibrational transitions in molecules. The instrumentation involves an infrared source, sample holder, and detector. Applications include identifying functional groups in organic molecules, determining drug formulations, and analyzing biological samples like urine.
Ir spectroscopy nd its applications copykeshav pai
Infrared spectroscopy is a technique that analyzes infrared light interacting with molecules. It can be used to identify unknown substances by comparing their infrared spectra to a reference database. The technique works because molecules absorb different wavelengths of infrared light depending on their chemical bonds and structure. Common applications of infrared spectroscopy include identification of materials, detection of impurities, and studying the progress of chemical reactions.
Uv visible spectroscopy with InstrumentationSHIVANEE VYAS
Spectroscopy is the study of interaction of electromagnetic radiation with matter. It involves measuring the spectrum (absorption or emission) of a sample when it interacts with electromagnetic radiation such as visible light, UV light, or infrared light. The main types of spectroscopy are absorption spectroscopy and emission spectroscopy. UV-visible spectroscopy measures absorption of ultraviolet and visible light by a substance in solution. It follows Beer-Lambert law where absorbance is directly proportional to concentration and path length of light through the sample. Electronic transitions that occur when absorbing UV-visible light include σ→σ*, n→π*, π→π*, etc. Factors like auxochromes, conjugation, and solvents can cause shifts in the absorption maximum
This document provides an overview of UV-visible spectroscopy. It discusses the electromagnetic spectrum and how light exhibits both wave and particle properties. It explains the basic components and principles of UV-visible spectrometers, including sources such as tungsten lamps and lasers, wavelength selectors like monochromators, sample containers, and various types of detectors. It also covers important concepts such as Beer's law, deviations from Beer's law, and the factors that affect spectroscopic measurements.
This document discusses the attenuated total reflectance (ATR) infrared spectroscopy sampling technique. It begins by introducing ATR and explaining that it allows for little to no sample preparation and a very thin sampling pathlength. It then discusses factors that affect the ATR spectrum such as the refractive indices of the crystal and sample, angle of incidence, depth of penetration, and quality of sample contact. Common ATR crystal materials and their spectral ranges and depths of penetration are presented. Applications include identification of functional groups, contaminated pet food detection, and more. In conclusion, ATR provides high quality reproducible data for a variety of solid and liquid samples.
Nuclear magnetic resonance spectroscopy techniques such as 13C NMR and 2D NMR experiments like COSY and HECTOR can be used to analyze organic compounds. [13C NMR provides information about the number and types of carbon atoms in a molecule based on their chemical shifts. Two-dimensional NMR experiments reveal coupling between nuclei like 1H-13C and 1H-1H couplings to help determine molecular structure.] DEPT NMR experiments distinguish between methylene, methine and methyl carbons. 13C NMR finds applications in fields like metabolic analysis, drug purity determination and polymer characterization.
This document discusses factors that affect fluorescence and phosphorescence. It defines fluorescence and phosphorescence as types of molecular luminescence that are excited by photon absorption. The main difference is that fluorescence involves no change in electron spin, while phosphorescence does involve a change. Several factors can influence emission, including molecular structure and rigidity, temperature, solvent properties, pH, dissolved oxygen, concentration, and the presence of heavy atoms. More rigid and planar structures favor fluorescence and phosphorescence. Higher temperatures, viscosities, and oxygen levels decrease emission, while appropriate solvent polarity and pH can increase it.
This document provides an overview of spectroscopy. It discusses topics like electromagnetic radiation, photons, wavelength, frequency, the electromagnetic spectrum, absorption spectroscopy, emission spectroscopy, Lambert's law, Beer's law, chromophores, auxochromes, shifts in absorption spectra, and components of a visible spectrophotometer like sources, filters, and monochromators.
INFRARED SPECTROSCOPY to find the functional groupssusera34ec2
This document provides an overview of infrared spectroscopy. It discusses the principle, theory, instrumentation, sample preparation, qualitative and quantitative analysis, uses, applications, and limitations. Infrared spectroscopy analyzes the infrared region of the electromagnetic spectrum to identify functional groups and compounds. The main instruments are dispersive spectrometers and Fourier transform infrared spectrometers. Infrared spectroscopy is widely used in research and industry for structure elucidation, compound identification, and determining organic and inorganic materials.
Fluorescence spectroscopy is a very advanced technology that uses the phenomena of fluorescence. This presentation covers the basic concepts, instrumentation, applications, advantages and disadvantages of the technique. It also covers the Jablonski diagram. The process that analyses and measure these types of emissions is known as Fluorescence spectroscopy.Fluorescence spectroscopy is a novel technique that is used for measuring the binding of ligands to the proteins in the presence of fluorphore that bound to the ligand .
The document discusses the applications of infrared (IR) spectroscopy for qualitative and quantitative analysis. IR spectroscopy can be used to identify functional groups and determine molecular structures. It allows study of hydrogen bonding, geometrical isomers, and reaction progress. Near IR is applied to agriculture and pharmaceutical analysis while mid IR identifies organic and biological species. Far IR is used in medical treatments and astronomy. In summary, IR spectroscopy enables structural analysis and has various applications across chemistry, biology, medicine, and astronomy.
There are four main techniques used to prepare solid samples for IR spectroscopy: dissolving solids in solution, solid films, mull technique, and pressed pellet technique. The mull technique involves grinding the solid sample with a mulling agent like mineral oil or nujol to form a paste between IR windows. The pressed pellet technique uses potassium bromide to form a compressed pellet, avoiding interference from a mulling agent. Liquids can be analyzed directly in liquid sample cells of appropriate thickness.
A method of obtaining an Infrared spectrum by measuring the interferogram of a sample using an interferometer, then performing a Fourier Transform upon the interferogram to obtain the spectrum.
2D NMR provides more information than 1D NMR by plotting data in a space defined by two frequency axes. There are several types of 2D NMR experiments including COSY, NOESY, and HETCOR. COSY identifies spin-coupled protons by showing cross peaks between protons that are directly bonded. NOESY correlates protons that are near each other in space but not necessarily directly bonded. HETCOR plots 1H and 13C spectra on separate axes and connects carbon signals to bonded proton signals. 2D NMR techniques provide additional structural information about molecules compared to traditional 1D NMR.
Infrared spectroscopy involves using infrared radiation to analyze materials. Molecules absorb specific infrared frequencies that are characteristic of their structure, such as bond vibrations and stretches. There are two main methods for infrared spectroscopy - scanning monochromator which analyzes one wavelength at a time, and Fourier transform infrared spectroscopy which uses interferometry to measure all infrared wavelengths simultaneously. Fourier transform then converts this raw interferogram data into the infrared spectrum. Infrared spectroscopy can be used to identify functional groups and molecular structures in compounds like 1-Hexene, Toluene, and Cyclohexanol based on their characteristic absorption peaks.
2D NMR techniques provide additional information beyond conventional 1D NMR. COSY identifies pairs of coupled protons, while HETCOR identifies the number of protons directly bonded to a particular carbon. NOESY and ROESY spectra locate protons that are close in space. DEPT distinguishes between carbon types such as CH3, CH2, CH, and quaternary carbons. Spin decoupling simplifies spectra by removing coupling between irradiated and non-irradiated protons.
Basics of Infrared Spectroscopy : Theory, principles and applicationsHemant Khandoliya
1. Spectroscopy involves using electromagnetic radiation to obtain information about atoms and molecules. Infrared (IR) spectroscopy specifically analyzes molecular vibrations that occur when IR radiation is absorbed.
2. IR spectroscopy is useful for structure elucidation and identification of organic compounds by determining their functional groups based on characteristic absorption bands. It can also be used to study reaction progress and detect impurities.
3. Factors like hydrogen bonding, coupling effects, and electronic effects can influence vibrational frequencies observed in IR spectra. Advanced applications include quantitative analysis, studying isomerism, and determining unknown contaminants.
Attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) is a technique where an infrared beam reflects off an internal reflection element and into a sample, generating an evanescent wave that penetrates into the sample. It requires little to no sample preparation and can analyze samples in less than a minute. The depth of penetration depends on factors like the wavelength and the refractive indexes of the sample and element. Common element materials include germanium, silicon, zinc selenide, and diamond. ATR-FTIR is useful for analyzing solids, liquids, powders and can characterize surface layers and opaque samples with limitations in sensitivity compared to transmission methods.
Infrared spectroscopy involves interaction of infrared radiation with matter. It covers absorption spectroscopy techniques and is conducted using an infrared spectrometer. The infrared region is divided into three regions based on wavelengths. Infrared spectroscopy follows Beer's law and analyzes the selective absorption bands in a sample's infrared spectrum to determine its molecular structure and identify functional groups, compounds, and impurities. It has applications in analyzing organic and inorganic compounds.
This document provides an overview of infrared spectroscopy. It discusses the principle that infrared spectroscopy involves absorption of infrared radiation which causes vibrational transitions in molecules. The instrumentation involves an infrared source, sample holder, and detector. Applications include identifying functional groups in organic molecules, determining drug formulations, and analyzing biological samples like urine.
Ir spectroscopy nd its applications copykeshav pai
Infrared spectroscopy is a technique that analyzes infrared light interacting with molecules. It can be used to identify unknown substances by comparing their infrared spectra to a reference database. The technique works because molecules absorb different wavelengths of infrared light depending on their chemical bonds and structure. Common applications of infrared spectroscopy include identification of materials, detection of impurities, and studying the progress of chemical reactions.
Uv visible spectroscopy with InstrumentationSHIVANEE VYAS
Spectroscopy is the study of interaction of electromagnetic radiation with matter. It involves measuring the spectrum (absorption or emission) of a sample when it interacts with electromagnetic radiation such as visible light, UV light, or infrared light. The main types of spectroscopy are absorption spectroscopy and emission spectroscopy. UV-visible spectroscopy measures absorption of ultraviolet and visible light by a substance in solution. It follows Beer-Lambert law where absorbance is directly proportional to concentration and path length of light through the sample. Electronic transitions that occur when absorbing UV-visible light include σ→σ*, n→π*, π→π*, etc. Factors like auxochromes, conjugation, and solvents can cause shifts in the absorption maximum
This document provides an overview of UV-visible spectroscopy. It discusses the electromagnetic spectrum and how light exhibits both wave and particle properties. It explains the basic components and principles of UV-visible spectrometers, including sources such as tungsten lamps and lasers, wavelength selectors like monochromators, sample containers, and various types of detectors. It also covers important concepts such as Beer's law, deviations from Beer's law, and the factors that affect spectroscopic measurements.
This document discusses the attenuated total reflectance (ATR) infrared spectroscopy sampling technique. It begins by introducing ATR and explaining that it allows for little to no sample preparation and a very thin sampling pathlength. It then discusses factors that affect the ATR spectrum such as the refractive indices of the crystal and sample, angle of incidence, depth of penetration, and quality of sample contact. Common ATR crystal materials and their spectral ranges and depths of penetration are presented. Applications include identification of functional groups, contaminated pet food detection, and more. In conclusion, ATR provides high quality reproducible data for a variety of solid and liquid samples.
Nuclear magnetic resonance spectroscopy techniques such as 13C NMR and 2D NMR experiments like COSY and HECTOR can be used to analyze organic compounds. [13C NMR provides information about the number and types of carbon atoms in a molecule based on their chemical shifts. Two-dimensional NMR experiments reveal coupling between nuclei like 1H-13C and 1H-1H couplings to help determine molecular structure.] DEPT NMR experiments distinguish between methylene, methine and methyl carbons. 13C NMR finds applications in fields like metabolic analysis, drug purity determination and polymer characterization.
This document discusses factors that affect fluorescence and phosphorescence. It defines fluorescence and phosphorescence as types of molecular luminescence that are excited by photon absorption. The main difference is that fluorescence involves no change in electron spin, while phosphorescence does involve a change. Several factors can influence emission, including molecular structure and rigidity, temperature, solvent properties, pH, dissolved oxygen, concentration, and the presence of heavy atoms. More rigid and planar structures favor fluorescence and phosphorescence. Higher temperatures, viscosities, and oxygen levels decrease emission, while appropriate solvent polarity and pH can increase it.
This document provides an overview of spectroscopy. It discusses topics like electromagnetic radiation, photons, wavelength, frequency, the electromagnetic spectrum, absorption spectroscopy, emission spectroscopy, Lambert's law, Beer's law, chromophores, auxochromes, shifts in absorption spectra, and components of a visible spectrophotometer like sources, filters, and monochromators.
INFRARED SPECTROSCOPY to find the functional groupssusera34ec2
This document provides an overview of infrared spectroscopy. It discusses the principle, theory, instrumentation, sample preparation, qualitative and quantitative analysis, uses, applications, and limitations. Infrared spectroscopy analyzes the infrared region of the electromagnetic spectrum to identify functional groups and compounds. The main instruments are dispersive spectrometers and Fourier transform infrared spectrometers. Infrared spectroscopy is widely used in research and industry for structure elucidation, compound identification, and determining organic and inorganic materials.
Fluorescence spectroscopy is a very advanced technology that uses the phenomena of fluorescence. This presentation covers the basic concepts, instrumentation, applications, advantages and disadvantages of the technique. It also covers the Jablonski diagram. The process that analyses and measure these types of emissions is known as Fluorescence spectroscopy.Fluorescence spectroscopy is a novel technique that is used for measuring the binding of ligands to the proteins in the presence of fluorphore that bound to the ligand .
This document discusses infrared (IR) spectroscopy, which analyzes the vibrational transitions of molecules to determine their functional groups. It describes the principle that IR radiation is absorbed when its frequency matches the natural vibration frequency of a molecule's bonds. The document outlines different types of vibrations, factors affecting frequencies, applications like pharmaceutical analysis, and provides examples of using IR spectroscopy to identify functional groups and fingerprints.
This document discusses infrared (IR) spectroscopy and how it can be used to analyze molecules. It provides background on the principles of IR spectroscopy, including how electromagnetic radiation causes vibrational and rotational excitations in covalent bonds. It describes different types of molecular vibrations that can be observed, such as stretching, bending, and rotational vibrations. It explains that IR active vibrations are those that cause a change in the molecular dipole moment. The document also outlines the basic components of an IR spectrometer and how IR spectra are recorded and interpreted.
This document provides an overview of various spectroscopy techniques including UV-Vis, IR, and NMR spectroscopy. It discusses key concepts like electromagnetic radiation, photon energy, and the electromagnetic spectrum. It describes the interactions between electromagnetic radiation and matter that are measured in different spectroscopy methods. It also provides examples of spectra for organic compounds and explanations of spectral features.
NIR spectroscopy is a technique that is widely used in pharmaceutical applications such as raw material identification, process monitoring, and finished product analysis. It works by measuring overtones and combinations of vibrational bonds like C-H, O-H, and N-H. Common instrumentation includes light sources, monochromators, sample holders, and detectors like PbS, PbSe, Si, InSb, and CCD. Applications include raw material and intermediate identification, tablet and capsule analysis, monitoring of processes like blending and coating, and agricultural uses like determining crop quality and chemical composition. Lyophilized products and final packaging can also be analyzed using NIR to ensure quality and identity.
Infrared spectroscopy is a technique that uses infrared radiation to study molecular vibrations. When the frequency of infrared radiation matches the natural vibrational frequency of a molecule, absorption occurs. Each bond type and molecular structure absorbs infrared radiation at characteristic frequencies. There are several types of molecular vibrations that can be observed using infrared spectroscopy including stretching and bending vibrations. Infrared spectroscopy has many applications such as identifying organic compounds, distinguishing between intramolecular and intermolecular hydrogen bonding, quantitative analysis, and studying chemical reactions by observing changes in absorption bands.
Infrared spectroscopy analyzes the absorption of infrared radiation by molecules to determine their structure. When IR radiation interacts with a molecule, it can cause the bonds and atoms within the molecule to vibrate. For a vibration to be IR active, it must cause a change in the molecule's dipole moment. IR spectroscopy is useful for identifying organic functional groups and determining molecular structure. It has applications in pharmaceutical analysis including identification of drugs and excipients, and quality control of drug formulations.
This document discusses various types of radiation detectors. It begins by explaining the need for detectors to measure ionizing radiation since our senses cannot detect it. The key detection methods discussed are ionization, luminescence, photographic effect, thermoluminescence, chemical effect, and biological effect. Specific detector types covered in detail include gas-filled detectors like ionization chambers and Geiger counters, scintillation detectors, semiconductor detectors, and dosimeters. The document provides information on how each type of detector works and its applications.
The infrared region of electromagnetic spectrum extents from
the red-end of visible spectrum out to microwave region.
The region includes radiation at wavelength between 0.75 and
300 microns or in wave numbers between 13,000 and 33 cm-1
This document describes a scintillation detector. It consists of a scintillator material that emits a flash of light when struck by ionizing radiation. A photodetector like a photomultiplier tube converts the light flashes into electrical pulses that can be analyzed. Scintillation detectors are widely used to detect various types of radiation in applications like radiation protection and medical imaging. They have advantages like efficiency and ease of use but require high voltage and can be affected by temperature and background radiation.
The document discusses Fourier transform infrared spectroscopy (FTIR). It begins by explaining the basic principles of FTIR including how a Fourier transform is used to convert infrared absorption data into a spectrum. It then describes key components of an FTIR instrument and how it works. The document outlines advantages such as high resolution and speed of analysis. Applications including structure determination and identification of organic compounds are also mentioned.
SPECTROSCOPY is defined as the study of the interactions between radiations and matter as function of wavelength λ .
Interactions with particle radiation or a response of a material to an altering field
or varying frequency.
SPECTRUM : A plot of the response as a function of wavelength or more commonly frequency is referred to as spectrum.
SPECTROMETRY : It is measurement of these responses and an instrument which performs such measurements is a spectrophotometer or spectrograph, although
these terms are more limited in use to original field of optics from which the
concept sprang.
Introduction
Instrumentation
Sampling techniques
Group frequencies
Factors affecting group frequencies
Complementarity of IR and Raman spectroscopy
Applications of Infrared spectroscopy
This document provides an overview of infrared spectroscopy, including:
- General uses such as identification of organic/inorganic compounds and determination of functional groups
- Common applications like identification of unknown compounds and reaction components
- Samples that can be analyzed as solids, liquids, or gases in small amounts
- Theory of infrared absorption involving molecular vibrations that change the dipole moment
This document discusses various types of radiation detectors. It begins by explaining that we cannot detect ionizing radiation with our senses and require instruments. There are two main components of radiation detectors - the detector where interactions take place, and a measuring device to record interactions. Important effects used in detection include ionization, luminescence, photographic effect, thermoluminescence, and chemical and biological effects. Common types of detectors discussed include ionization chambers, proportional counters, Geiger-Muller counters, scintillation detectors, semiconductor detectors, and thermoluminescent dosimeters. The document provides details on the operation and uses of different detectors.
Infrared spectroscopy involves using infrared light to analyze chemical bonding and molecular structure. Infrared light is passed through a sample, and the wavelengths absorbed can be measured to identify chemical groups and determine structural features. The technique is widely used to analyze organic materials and identify unknown compounds based on their infrared absorption spectra. Limitations include an inability to determine molecular weight or relative positions of functional groups within a molecule from the infrared spectrum alone.
These lecture slides, by Dr Sidra Arshad, offer a simplified look into the mechanisms involved in the regulation of respiration:
Learning objectives:
1. Describe the organisation of respiratory center
2. Describe the nervous control of inspiration and respiratory rhythm
3. Describe the functions of the dorsal and respiratory groups of neurons
4. Describe the influences of the Pneumotaxic and Apneustic centers
5. Explain the role of Hering-Breur inflation reflex in regulation of inspiration
6. Explain the role of central chemoreceptors in regulation of respiration
7. Explain the role of peripheral chemoreceptors in regulation of respiration
8. Explain the regulation of respiration during exercise
9. Integrate the respiratory regulatory mechanisms
10. Describe the Cheyne-Stokes breathing
Study Resources:
1. Chapter 42, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 36, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 13, Human Physiology by Lauralee Sherwood, 9th edition
NAVIGATING THE HORIZONS OF TIME LAPSE EMBRYO MONITORING.pdfRahul Sen
Time-lapse embryo monitoring is an advanced imaging technique used in IVF to continuously observe embryo development. It captures high-resolution images at regular intervals, allowing embryologists to select the most viable embryos for transfer based on detailed growth patterns. This technology enhances embryo selection, potentially increasing pregnancy success rates.
- Video recording of this lecture in English language: https://youtu.be/Pt1nA32sdHQ
- Video recording of this lecture in Arabic language: https://youtu.be/uFdc9F0rlP0
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Kosmoderma Academy, a leading institution in the field of dermatology and aesthetics, offers comprehensive courses in cosmetology and trichology. Our specialized courses on PRP (Hair), DR+Growth Factor, GFC, and Qr678 are designed to equip practitioners with advanced skills and knowledge to excel in hair restoration and growth treatments.
Travel Clinic Cardiff: Health Advice for International TravelersNX Healthcare
Travel Clinic Cardiff offers comprehensive travel health services, including vaccinations, travel advice, and preventive care for international travelers. Our expert team ensures you are well-prepared and protected for your journey, providing personalized consultations tailored to your destination. Conveniently located in Cardiff, we help you travel with confidence and peace of mind. Visit us: www.nxhealthcare.co.uk
Breast cancer: Post menopausal endocrine therapyDr. Sumit KUMAR
Breast cancer in postmenopausal women with hormone receptor-positive (HR+) status is a common and complex condition that necessitates a multifaceted approach to management. HR+ breast cancer means that the cancer cells grow in response to hormones such as estrogen and progesterone. This subtype is prevalent among postmenopausal women and typically exhibits a more indolent course compared to other forms of breast cancer, which allows for a variety of treatment options.
Diagnosis and Staging
The diagnosis of HR+ breast cancer begins with clinical evaluation, imaging, and biopsy. Imaging modalities such as mammography, ultrasound, and MRI help in assessing the extent of the disease. Histopathological examination and immunohistochemical staining of the biopsy sample confirm the diagnosis and hormone receptor status by identifying the presence of estrogen receptors (ER) and progesterone receptors (PR) on the tumor cells.
Staging involves determining the size of the tumor (T), the involvement of regional lymph nodes (N), and the presence of distant metastasis (M). The American Joint Committee on Cancer (AJCC) staging system is commonly used. Accurate staging is critical as it guides treatment decisions.
Treatment Options
Endocrine Therapy
Endocrine therapy is the cornerstone of treatment for HR+ breast cancer in postmenopausal women. The primary goal is to reduce the levels of estrogen or block its effects on cancer cells. Commonly used agents include:
Selective Estrogen Receptor Modulators (SERMs): Tamoxifen is a SERM that binds to estrogen receptors, blocking estrogen from stimulating breast cancer cells. It is effective but may have side effects such as increased risk of endometrial cancer and thromboembolic events.
Aromatase Inhibitors (AIs): These drugs, including anastrozole, letrozole, and exemestane, lower estrogen levels by inhibiting the aromatase enzyme, which converts androgens to estrogen in peripheral tissues. AIs are generally preferred in postmenopausal women due to their efficacy and safety profile compared to tamoxifen.
Selective Estrogen Receptor Downregulators (SERDs): Fulvestrant is a SERD that degrades estrogen receptors and is used in cases where resistance to other endocrine therapies develops.
Combination Therapies
Combining endocrine therapy with other treatments enhances efficacy. Examples include:
Endocrine Therapy with CDK4/6 Inhibitors: Palbociclib, ribociclib, and abemaciclib are CDK4/6 inhibitors that, when combined with endocrine therapy, significantly improve progression-free survival in advanced HR+ breast cancer.
Endocrine Therapy with mTOR Inhibitors: Everolimus, an mTOR inhibitor, can be added to endocrine therapy for patients who have developed resistance to aromatase inhibitors.
Chemotherapy
Chemotherapy is generally reserved for patients with high-risk features, such as large tumor size, high-grade histology, or extensive lymph node involvement. Regimens often include anthracyclines and taxanes.
5-hydroxytryptamine or 5-HT or Serotonin is a neurotransmitter that serves a range of roles in the human body. It is sometimes referred to as the happy chemical since it promotes overall well-being and happiness.
It is mostly found in the brain, intestines, and blood platelets.
5-HT is utilised to transport messages between nerve cells, is known to be involved in smooth muscle contraction, and adds to overall well-being and pleasure, among other benefits. 5-HT regulates the body's sleep-wake cycles and internal clock by acting as a precursor to melatonin.
It is hypothesised to regulate hunger, emotions, motor, cognitive, and autonomic processes.
Are you looking for a long-lasting solution to your missing tooth?
Dental implants are the most common type of method for replacing the missing tooth. Unlike dentures or bridges, implants are surgically placed in the jawbone. In layman’s terms, a dental implant is similar to the natural root of the tooth. It offers a stable foundation for the artificial tooth giving it the look, feel, and function similar to the natural tooth.
Lecture 6 -- Memory 2015.pptlearning occurs when a stimulus (unconditioned st...AyushGadhvi1
learning occurs when a stimulus (unconditioned stimulus) eliciting a response (unconditioned response) • is paired with another stimulus (conditioned stimulus)
Summer is a time for fun in the sun, but the heat and humidity can also wreak havoc on your skin. From itchy rashes to unwanted pigmentation, several skin conditions become more prevalent during these warmer months.
Cell Therapy Expansion and Challenges in Autoimmune DiseaseHealth Advances
There is increasing confidence that cell therapies will soon play a role in the treatment of autoimmune disorders, but the extent of this impact remains to be seen. Early readouts on autologous CAR-Ts in lupus are encouraging, but manufacturing and cost limitations are likely to restrict access to highly refractory patients. Allogeneic CAR-Ts have the potential to broaden access to earlier lines of treatment due to their inherent cost benefits, however they will need to demonstrate comparable or improved efficacy to established modalities.
In addition to infrastructure and capacity constraints, CAR-Ts face a very different risk-benefit dynamic in autoimmune compared to oncology, highlighting the need for tolerable therapies with low adverse event risk. CAR-NK and Treg-based therapies are also being developed in certain autoimmune disorders and may demonstrate favorable safety profiles. Several novel non-cell therapies such as bispecific antibodies, nanobodies, and RNAi drugs, may also offer future alternative competitive solutions with variable value propositions.
Widespread adoption of cell therapies will not only require strong efficacy and safety data, but also adapted pricing and access strategies. At oncology-based price points, CAR-Ts are unlikely to achieve broad market access in autoimmune disorders, with eligible patient populations that are potentially orders of magnitude greater than the number of currently addressable cancer patients. Developers have made strides towards reducing cell therapy COGS while improving manufacturing efficiency, but payors will inevitably restrict access until more sustainable pricing is achieved.
Despite these headwinds, industry leaders and investors remain confident that cell therapies are poised to address significant unmet need in patients suffering from autoimmune disorders. However, the extent of this impact on the treatment landscape remains to be seen, as the industry rapidly approaches an inflection point.
Medical Quiz ( Online Quiz for API Meet 2024 ).pdf
Infrared Spectroscopy
1. Professor, Department of Pharmaceutical Analysis,
Santhiram College of Pharmacy, Nandyal, Kurnool Dist. AP. India.
drbmdishaq@gmail.com
AICTE PRERANA Virtual GPAT Class for
B. Pharmacy students
http://srcpnandyal.com/
2. All the information and views shared in this presentation belongs
solely to me and not necessarily to my employer, organization,
committee or other group or individual. This presentation is
delivered with the whole and sole educational purpose of students
and not involved any commercial benefits. Thus the presenter or
his employer neither claim for any copyright nor responsible for
any sort of copyright issues arise.
DISCLAIMER
4. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Spectroscopy
“Seeing the unseen”. Molecular Eye
Spectroscopy is the branch of science that deals the study of
interaction of electromagnetic radiation with matter.
Electromagnetic radiation is a type of energy that is
transmitted through space at enormous velocities.
EMR Analyte (low conc.) Spectra
5. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Using electromagnetic radiation as a probe to obtain information
about atoms and molecules that are too small to see.
Electromagnetic radiation is propagated at the speed of light
through a vacuum as an oscillating wave.
Electromagnetic relationships:
λυ = c
E = hυ
E = hc/λ
λ 1/υ
E υ
E 1/λ
λ = wave length
υ = frequency
c = speed of light
E = kinetic energy
h = Planck’s constant
6.626 × 10−34 joule second.
7. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Infrared spectroscopy (IR) measures the bond vibration
frequencies in a molecule and is used to determine the
functional groups.
The infrared region of the spectrum encompasses radiation with
wave numbers ranging from about 12,500 to 50cm-1 (or) wave
lengths from 0.8 to 200µ.
IR SPECTROSCOPY
The infrared region constitutes 3 parts
a) The near IR (0.8 -2.5µm) (12,500-4000 cm-1)
b) The middle IR (2.5 -15µm) (4000-667 cm-1)
i) Group frequency Region (4000-1500 cm-1)
ii)Finger print Region (1500-400 cm-1)
c) The far IR (15-200µm) (400-40 cm-1)
8. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
In any molecule it is known that atoms or groups of atoms are
connected by bonds.
These bonds are analogous to springs and not rigid in
nature.
Because of the continuous motion of the molecule they
maintain some vibrations with some frequency
characteristic to every portion of the molecule. This is called
the natural frequency of vibration.
When energy in the form of infrared radiation is applied and
when, Applied infrared frequency= Natural frequency of
vibration, a signal corresponding to the energy transferred is
obtained.
PRINCIPLE
10. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
For a molecule to be IR active there must be a change in dipole
moment as a result of the vibration that occurs when IR radiation is
absorbed.
Dipoles need not be permanent. A small change in dipole is
sufficient to absorb IR radiation.
Homonuclear diatomic molecules such as N2 and O2 do not have
dipole moments. If such molecules undergoes a stretching
vibration, there is no change in the dipole moment during the
vibrational motion, therefore N2 and O2 do not absorb infrared
radiation.
11. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
There are 2 types of vibrations.
Stretching vibrations
Bending vibrations
• 1) Stretching vibrations: in this bond length is altered.
• They are of 2 types
• a) symmetrical stretching and b) Asymmetrical stretching
MOLECULARVIBRATIONS
12. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
2)Bending vibrations:
•These are also called as deformations.
•These are of 2 types
•a) In plane bending → Scissoring Rocking
•b) Out plane bending→ Wagging Twisting
13. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Molecular vibrations and Hooke’s Law
The stretching frequency of a bond can be approximated by
Hooke’s Law.
Hooke’s law describes the relationship of frequency to mass and
bond length.
The frequency of bond vibration can be derived from Hooke’s law,
which describes the motion of a vibrating spring:
• The force constant (f) is the strength of the bond (or spring). The
larger the value of f, the stronger the bond, and the higher the υ of
vibrations.
•The mass (m) is the mass of atoms. The smaller the value of m, the
higher the υ of vibration.
14. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
FUNDAMENTAL VIBRATIONALMODES
A molecule can vibrate in many ways, and each way is called a
vibrational mode.
The number of possible vibrations for a molecule is determined by
the degrees of freedom of the molecule.
If a molecule contains ‘N’ atoms, will have 3N degrees of
freedom.
For linear molecule it is (3N-5)
For non linear molecule it is (3N-6)
17. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Factors influencing Vibration Frequencies
Calculated value of frequency of absorption for a particular
bond is never exactly equal to its experimental value.
There are many factors which are responsible for vibration shifts
1. Vibration coupling
2. Hydrogen bonding
3. Electronic effect (Mesomeric effect and Inductive effect)
4. Overtone & Fermi-Resonance
18. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Vibration coupling
An isolated C-H Bond has only one stretching
vibrational frequency, whereas –CH2 (Methylene) group
shows two stretching they are: Symmetrical and
asymmetrical.
Because of mechanical coupling or interaction between
C-H stretching vibrations in the CH2 group.
Assymetric vibration require more energy to take place
so, it will occur at higher frequencies or wave numbers
than symmetrical vibrations.
As these vibration occur at different frequencies than
the required for an isolated C-H stretching, these types of
vibrations are called coupled vibrations.
19. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Hydrogen bonding
Hydrogen bonding brings about remarkable downward
frequency shifts.
Stronger the hydrogen bonding, greater is the absorption shift
towards lower wave length than the normal value.
There is 2 types of hydrogen bonding
a) inter molecular→broad bands
b) intra molecular → sharp bands
The inter and intra molecular hydrogen bonding can be
distinguished by dilution.
Intramolecular hydrogen bonding remains unaffected on dilution
and as a result absorption band also remains unaffected
Inter molecular, bonds are broken on dilution and as a result there
is a decrease in the bonded O-H absorption.
20. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Electronic effects
Inductive Effect:
21. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
It causes lengthening or the weakening of a bond leading in the
lowering of absorption frequency.
As Nitrogen atom is less electronegative than oxygen atom, the
electron pair on nitrogen atom in amide is more labile and
participates more in conjugation.
Due to this greater degree of conjugation, the C=O absorption
frequency is much less in amides as compared to that in esters.
Mesomeric effects
22. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Overtone & Fermi-Resonance
Fermi Resonance Coupling of a
fundamental vibration with an
overtone
24. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
There are 2 types of infrared spectrophotometer, characterized
by the manner in which the ir frequencies are handled.
1) dispersive type (IR)
2) Interferometric type (FTIR)
TYPES OF INSTRUMENTATION
In dispersive type the infrared light is separated into individual
frequencies by dispersion, using a grating monochromator.
In interferometric type the IR frequencies are allowed to interact
to produce an interference pattern and this pattern is then analyzed,
to determine individual frequencies and their intensities.
25. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Dispersion Spectrometer
In order to measure an IR
spectrum, the dispersion
Spectrometer takes several
minutes.
Also the detector receives only
a few % of the energy of
original light source.
FTIR
In order to measure an IR
spectrum, FTIR takes only a few
seconds.
Moreover, the detector receives
up to 50% of the energy of
original light source.
(much larger than the
dispersion spectrometer.)
Comparison Beetween Dispersion Spectrometer and FTIR
26. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
PARTS OF INSTRUMENTATION
• I R Radiation Source
– Incandescent lamp
– Nernst Glower (Composed of rare earth oxides
such as Zirconia, Yttria & Thoria)
– Globar Source (silicon carbide)
– Mercury Arc
• Sample Cells & Sampling Substances
– Sampling of solids
• Solids run solution
• Solid films
• Mull technique
• Pressed pellet technique
– Sampling of Liquids
– Sampling of Gases
• Detectors
– Bolometers
– Thermocouple
– Thermistors
– Golay Cells
– Photoconductivity cell
– Semiconductor
– Pyroelectric detectors
•Monochromators
27. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Identification of organic
compounds by IR Spectroscopy
(Interpretation of Spectra)
29. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
A. Introduction
1. When approaching any IR spectrum be sure to use the larger-to-smaller
region approach- do not immediately focus on any one single peak
(even –OH or C=O)
2. From the Hooke’s Law derivation we are using we find that the IR can be
conveniently be divided into four major regions:
Bonds to H Triple bonds Double bonds Single Bonds
O-H
N-H
C-H
C≡C
C≡N
C=O
C=N
C=C
C-C
C-N
C-O
C-X
“Fingerprint
Region”
4000 cm-1 2700 cm-1 2000 cm-1 1600 cm-1 400 cm-1
32. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
Before we begin – Each functional group will be described as follows:
Group
General – What is most recognizable? What makes it different from similar
groups?
Group Frequencies (cm-1):
Bond
observed
n in cm-1 type of vibration Exceptions and things to watch
Scale on bottom summarizes band positions and strengths
Strong - Medium - Weak -
33. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
The Hydrocarbons
Alkanes
General – due to the small electronegativity difference between C and H,
hydrocarbon bands are of medium intensity at best and give simple
spectra
Group Frequencies (cm-1):
C-H 3000-2800 Stretch Strained ring systems may have
higher n
-CH2- ~1465 Methylene bend (scissor)
-CH3 ~1375 Methyl bend (sym)
-(CH2)4- ~720 Rocking motion 4 or more
–CH2- (long chain band)
C-C Not interpretively useful,
small weak peaks
34. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
The Hydrocarbons
Alkanes – Dodecane – C12H26
35. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
The Hydrocarbons
Alkanes – Cyclopentane – C5H10
36. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
The Hydrocarbons
Alkenes
General – slightly more complex than alkanes; asymmetric C=C is observed as
well as the sp2-C-H stretch. Still, bands are weak to medium in intensity
Group Frequencies (cm-1):
=C-H 3095-3010 Stretch - Diagnostic for unsaturation- may be
aromatic as well
=C-H 1000-650 Out-of-plane (oop) bend - Can be used to determine degree
of substitution
C=C 1660-1600 Stretch - Can be reduced by resonance
- Symmetrical C=C do not absorb
- trans- weaker than cis-
37. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
The Hydrocarbons
Alkenes – 1-octene – C8H16
Note – you still have alkane present!
38. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
The Hydrocarbons
Alkenes – trans-4-octene – C8H16
Note – absence of C=C band, shouldering of C-H band
39. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
The Hydrocarbons
Alkynes
General – can be symmetric, psuedo-symmetric or internal – greatly reducing
the number of observed bands
Group Frequencies (cm-1):
C-H ~3300 Stretch - Diagnostic for terminal alkyne
CC ~2150 Stretch - Can be reduced by resonance
-Symmetrical and psuedo-sym. CC
do not absorb
C-H 900-700 Bend (Text does not list)
Possible not to observe any bands
for the CC system
40. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
The Hydrocarbons
Alkynes – 1-hexyne – C6H10
Nice terminal, asymmetric, well behaved alkyne
C
HC
41. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
The Hydrocarbons
Alkynes – 3-hexyne – C6H10
A not-so-nice, internal, symmetrical alkyne C
C
42. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
sp3 Oxygen – Alcohols, phenols and ethers
Alcohols
General – the best recognized group on carefully selected spectra, but H-
bonding effects can drastically change the position, intensity and shape of
the O-H band
Group Frequencies (cm-1):
O-H
(free)
3650-3600 Stretch Seen in dilute solution or gas
phase spectra
O-H
(H-bond)
3400-3300 Stretch The “classic” H-bonded band,
seen in addition to the free band
in solution
C-O-H 1440-1220 Bend Often obscured by -CH3 bend
C-O 1260-1000 Stretch Can be used to determine 1o, 2o,
3o or phenolic structure
43. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
sp3 Oxygen – Alcohols, phenols and ethers
Alcohols – 1-octanol
Neat liquid sample gives classic spectrum HO
44. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
sp3 Oxygen – Alcohols, phenols and ethers
Ethers
General – like alkynes, the simplicity of the spectra may allow them to pass
unnoticed – deduce from molecular formula if one should be present
Group Frequencies (cm-1):
C-O 1300-1000 Stretch (asymm.) Absence of C=O and O-H will
confirm it is not ester or alcohol
Simple alkyl ethers usually one
band at 1120, aryl alkyl ethers
give two bands – 1250 & 1040
45. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
sp3 Oxygen – Alcohols, phenols and ethers
Ethers – diispropyl ether
Spectrum dominated by all other functionality O
46. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
sp3 Nitrogen – Amines
Amines – Once presence is determined, the substitution at nitrogen is easy
to determine; only the 3° amine may present a problem
Group Frequencies (cm-1):
N-H
(-NH2)
3650-3600
(2 bands)
1640-1560
Stretch (sym. and asym.)
Bend
N-H
(-NHR)
3400-3300
(1 band)
1500
Stretch
Bend
For alkyl amines, very weak –
for aromatic 2° amines, stronger
N-H ~800 Oop bend
N-N 1350-1000 Stretch Remember 3° amines have no
N-H bands
47. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
E. Carbonyls
General – Along with alcohols, the most ubiquitous group on the IR spectrum.
Although it is easy to determine if the C=O is present, deducing the exact
functionality and factors that influence the position of the band provide
the challenge
Base C=O Frequencies (cm-1):
C=O 1810 Stretch (sym.) Anhydride band 1
1800 Acid Chloride
1760 Anhydride band 2
1735 Ester
1725 Aldehyde
1715 Ketone
1710 Carboxylic Acid
1690 Amide
48. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
Carbonyls
1. Ketones – Simplest carbonyl group, for a single carbonyl compound,
implied by a lack of any other functionality except hydrocarbon
Group Frequencies (cm-1):
C=O 1715 Stretch (sym.) n Base, sensitive to change
conj.
w/C=C
1700-1675 nC=C reduced to 1644-1617
conj.
w/Ph
1700-1680 nring 1600-1450
C=O 1815-1705 Decreased ring size raises n
1300-1100 Bend
C
C
C
O
49. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
Carbonyls
2. Aldehydes – Presence of the unique carbonyl C-H bond differentiates
this group from ketones
Group Frequencies (cm-1):
C=O 1725 Stretch (sym.) n Base, sensitive to change
conj.
w/C=C
1700-1680 nC=C reduced to 1640
conj.
w/Ph
1700-1660 nring 1600-1450
2820,
2720
Stretch Fermi doublet; Higher n band
often obscured by sp3 C-H
R
C
H
O
50. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
Carbonyls
3. Carboxylic Acids – Various H-bonding effects lead to messy spectra,
especially in the upper frequency ranges – be aware of the effects of
monomeric, dimeric and oligomeric species on the spectrum
Group Frequencies (cm-1):
C=O 1710 Stretch (sym.) n Base, sensitive to change;
conjugation gives reduced n
C-O 1320-1210 Stretch
O-H 3400-2400 Stretch Overlaps C-H region in most
cases; multiple “sub-peaks” can
be seen for the dimeric and
oligomeric species – simplified in
non-polar solution or gas phase
spectra
51. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Group Frequencies and Analysis
E. Carbonyls
4. Esters – Ester oxygen has an electron withdrawing effect that tends to
draw in electrons within the C=O system, strengthening it compared to
other carbonyls
Group Frequencies (cm-1):
C=O 1735 Stretch (sym.) n Base, sensitive to change
conj.
C=C
1735-1715 nC=C reduced to 1640-1625
w/Ph 1735-1715 nring 1600-1450
conj. of
sp3 O
1765-1760
1850-1740 nC=O increases with smaller ring
C-O 1300-1000 Stretch, 2 bands
C
O
O
52. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
Applications of Infrared Analysis
Pharmaceutical research
Forensic investigations
Polymer analysis
Lubricant formulation and fuel additives
Foods research
Quality assurance and control
Environmental and water quality analysis methods
Biochemical and biomedical research
Coatings and surfactants
Etc.
53. Santhiram College of pharmacy, Nandyal, Kurnool Dist. AP. 518501.
References :
Lena Ohannesian, Antony J. Streeter; Handbook of
Pharmaceutical Analysis; Marcel Dekker, Inc.; Reprint 2002
Chatwal and Anand ; Instrumental methods of chemical analysis;
fifth edition; page no-2.43-46
Spectrometric identification of organic compounds, R M
Silverstein,T.C morril G.C. bassler Fifth edition, p.no.99-100
Internet :
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www.authorstream.com
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