ITS AGAIN AN IMPORTANT TOPIC OF ANALYTICAL CHEMISTRY WHERE C13 IS AN TYPE OF NUCLEAR MAGNETIC RESONANCE ALONG WITH PROTON NMR. STUDY THIS TOPIC WELL FOR BTTER UNDERTSANDING OF NMR WHICH IS BELIEVED TO BE ONE OF THE TOUGH PART.
HOPE YOU ALL WILL USE IT WELL.
ITS AGAIN AN IMPORTANT TOPIC OF ANALYTICAL CHEMISTRY WHERE C13 IS AN TYPE OF NUCLEAR MAGNETIC RESONANCE ALONG WITH PROTON NMR. STUDY THIS TOPIC WELL FOR BTTER UNDERTSANDING OF NMR WHICH IS BELIEVED TO BE ONE OF THE TOUGH PART.
HOPE YOU ALL WILL USE IT WELL.
A mass spectrum (MS) is a graphical representation of the relative abundance of ions at different mass-to-charge ratios (m/z) in a sample. Mass spectrometry is a powerful analytical technique used to identify and characterize the chemical composition of a wide range of substances, including organic compounds, proteins, peptides, and even small molecules. Here's how a typical mass spectrum is generated and what it can tell you:
Ionization: In mass spectrometry, the sample is first ionized, meaning that the atoms or molecules are converted into ions (charged particles). Common ionization methods include electron impact, electrospray ionization, and matrix-assisted laser desorption/ionization (MALDI).
Mass-to-Charge Ratio (m/z): After ionization, the ions are separated based on their mass-to-charge ratio (m/z). This ratio is a dimensionless quantity, and it represents the mass of the ion (in atomic mass units, amu) divided by its charge (in elementary charge units, e).
Ion Separation: The ions are separated by a mass analyzer, such as a magnetic sector, time-of-flight (TOF), quadrupole, or ion trap, depending on the specific instrument used. The mass analyzer sorts ions according to their m/z values.
Detector: As the ions exit the mass analyzer, they are detected, and their abundance is recorded. The detector measures the number of ions at each m/z value.
Data Output: The data from the detector is then used to create a mass spectrum. The x-axis of the mass spectrum represents m/z values, while the y-axis represents the relative abundance or intensity of ions at each m/z value.
A typical mass spectrum might have peaks at specific m/z values, and these peaks can provide valuable information about the sample:
Base Peak: The peak with the highest intensity in the spectrum is called the base peak. It represents the most abundant ion.
Molecular Ion Peak: The peak at the highest m/z value (farthest to the right) often represents the molecular ion, which can provide insight into the molecular weight of the compound.
Fragment Peaks: Peaks at lower m/z values are often fragment ions resulting from the breaking of chemical bonds within the original ions. These fragment ions can provide information about the structure of the compound.
Isotopic Peaks: Some elements have natural isotopes, and their presence can result in multiple peaks with slightly different m/z values. These isotopic peaks can also provide information about the composition of the sample.
Interpreting a mass spectrum involves analyzing the positions and intensities of these peaks to identify the compound and its structure. Mass spectrometry is widely used in various fields, including chemistry, biochemistry, environmental science, and forensic analysis, for tasks such as identifying unknown substances, quantifying the amounts of specific compounds, and studying chemical reactions.
In organic chemistry, an alkyne is an unsaturated hydrocarbon containing at least one carbon—carbon triple bond. The simplest acyclic alkynes with only one triple bond and no other functional groups form a homologous series with the general chemical formula CₙH₂ₙ−2
Basic principles & questions and answers of organic chemistry Bryar Ali Rus
this is some basic principles and question & answers of previous years of organic chemistry with notes on dr.emad manhal's examination , school of pharmacy , university of sulaimani .
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
5. Mass spectrum
Mass spectrum
A graph of the relative abundance of each
fragment plotted against its m/z value.
The x-axis, in units of m/z, represents the
formula weight of the detected ions.
The y-axis represents the relative abundance
of each detected ion.
The most abundant ion (tallest peak) is called
the base peak.
The peak at high m/z, is known as molecular
ion peak
.
Fragmentation
peaks
Base
peak
6. 13 RULE
The Rule of Thirteen is so named because, to generate a base formula
(containing only carbon and hydrogen); the molar mass of the substance
is divided by 13. The numerator from division gives the number of carbon
atoms in the base formula. The remainder, when added to the numerator,
gives the number of hydrogen’s in the base formula.
M+/13 H=n+r CnHn+r
If you have heteroatoms, you adjust the formula. For example:
For O, add O and subtract CH4.
For N, add N and subtract CH2.
For 35Cl, add Cl and subtract C2H11,etc.
7. Nitrogen rule
If a compound contain odd number of nitrogen then, its molecular ion peak
will appear at an odd mass value.
If a compound contain even number of nitrogen or no nitrogen then, its
molecular ion peak will appear at an even mass value.
This rule is very useful determining the nitrogen content of an unknown
compound.
8. Hydrogen Deficient Index (HDI)
OR
Index Of Hydrogen Deficiency
Or
Degree Of Unsaturation
Its used to determine how many rings, double bonds, and triple bonds are
present in the compound to be drawn.
Formula for HDI=(x+1)-1/2(y)+1/2(z)
x=tetravalent y=monovalent z=trivalent
10. Molecularion
peakat86
By applying above three rules on
mass spectrum
For carbon
13 rule=molecular ion peak/13
13)86(6 numerator (n)
-78
8 reminder(r)
It means over compound have 6
carbon.
For hydrogen = n+r
=6+8=14
So base formula is C6H14
HDI=(x+1)-1/2(y)+1/2(z)
=(6+1)-1/2(14)+1/2(0)
=(7)-(7)+(0)
HDI=0
HDI is zero so there will be no
unsaturation .
Nitrogen rule as its molecular ion peak
does not appear at an odd mass
value, so presence of single nitrogen
is not possible
Finally we can say that it’s a compound that doesn’t have any
ring or any double bond
Also we knew that no single nitrogen is present and our
comound have C6H14 no any other hint is given for
heteroatom.
M-15
M-29
M-43
M-57
11. • Molecular ion peak observed,
their intensity is inversely
proportional to the No: of carbon
atoms.
• Their fragments are at M-15,
M-29, M-43 etc.
• Base peak is observed at 43, 57
etc. Depend upon quantity of
carbon in the chain.
• Bond cleavage takes place at
the site of branches.
• Due to stable carbocation the
further fragmentation is
favored as a result weak M+
peak occurs.
• No: of branches of alkanes is
inversely proportional to the
intensity of molecular ion peak.
13. • Base peak is at 43 due to
higher abundance of propyl
ion
• CH3-CH2-CH2-CH2-CH3
• Possibility of base peak is:
• CH3-CH2-CH2-CH2-CH3
• CH3-CH2-CH2
+ & .CH2-CH3
pentane
14. Mass spectrum of pentane vs. 2-methylbutane: Both mass spectra are similar to each other with two
notable exception, one the peak in 2-methylbutane at 57 is much more intense than normal pentane and
other is the molecular ion peak is less intense in 2-methylbutane.
.
15. • Fairly prominent M+ peak.
• Terminal alkenes lose allylic cation if possible.
• Most common fragmentation is the cleavage
of allylic bond.
• Positive charge usually remains with the fragments containing double bond in order to give
a resonance stabilized allylic cation.
McLafferty rearrangement may occur when there is a gamma carbon with hydrogen.
• 1-butene and 2-butene Mass spectra are identical –not a good method for alkene
isomer.
17. M+2 (isotopic) peak is observed.
• For bromine isotopic abundance is 1:1 and for chlorine it is of 1:3, due
to natural abundance of halogen (bromine & chlorine).
• Elimination reaction takes place.
• α- cleavage takes place.
• Molecular ion peak is observed.
20. • Intensity of molecular ion peak is depend upon substitute.
• Substitute is inversely proportional to the abundance of molecular ion
peak.
• Primary M+ peak is weak.
• Secondary M+ peak is weakest.
• Tertiary M+ peak is usually absent.
• M-17 peak is observed due to removal of –OH group.
• M-18 peak is observed due to formation of water.
(Elimination reaction)
21. • Base peak is observed at:
• m/z = 31 for primary.
• m/z = 45 for secondary.
• m/z = 59 for tertiary.
Possible Fragmentation
• Elimination.
• α- cleavage.
• β-cleavage.
24. • Base peak is usually lose of alkyl radical.
• The peak formed due to acylium ion is most abundant peak at m/z = 43
• Loss of large alkyl radical favors the ketone in α- cleavage.
• McLafferty rearrangement also occurs.
• α- cleavage takes place.
• Molecular ion peak is observed.
26. M-17 (-OH group) indicates the presence of carboxylic acid.
• Peaks observed at:
• Molecular ion is observed but low abundance.
M-45 (-COOH group) is also observed.
Possible Fragmentation
• α- cleavage.
• β-cleavage.
• McLafferty rearrangement
28. Identify molecule.
Identify the functional group.
Identify molecular ion peak.
Construct the molecule by using base peak, fragmentation & functional
group.
29. • Introduction to Spectroscopy by Pavia.
• Elementary Organic Spectroscopy by Y.R.Sharma.
• Organic chemistry 4th edition by paula yurkanis bruice chapter no#13
mass spectrometry & infrared spectroscopy
• Organic Chemistry by Robert Thornton Morrison, 6th edition.
• Web Sources.
30. I am extremely grateful to almighty ALLAH for His blessings over me
during up and downs of my life.
