These are chemical shift reagents and solvent induced shifts have their application in resolving the NMR Spectra of complex structures by inducing shift with respect to reference compound. Thus useful in interpretation of structures of complex organic compounds.
This presentation describes about the preparation, properties, bonding modes, classification and applications of metal Dioxygen Complexes. Also explains the MO diagram of molecular oxygen.
This presentation describes about the preparation, properties, bonding modes, classification and applications of metal Dioxygen Complexes. Also explains the MO diagram of molecular oxygen.
Introductory PPT on Metal Carbonyls having its' classification,structure and applications.This is a basic level PPT specially prepared for UG/PG Chemistry students.
It contains what are the shift reagents, and how they will use in NMR spectroscopy. It includes lanthanide shift reagents and their effect using NMR spectroscopy. It has mostly used shift reagents like Europium and their importance. paramagnetic species that affect the NMR spectra are also explained in detail. What are contact shift and pseudo-contact shift also explained. It contains what are the chiral shift reagent, and the advantages, and disadvantages of lanthanide shift reagents. Reference books are also included.
THE PERICYCLIC REACTION THE MOST COMMON TOPIC INCLUDE THE SYLLABUS OF MANY SCIENCE STUDY INCLUDING BSC, MSC , PHARMA STUDY, AND MORE HENCE WE ARE COVERED ALL THE DATA OF IT HOPE THIS WILL MAKE READER EASY.
An overview of the use of the Marcus Theory to calculate the energies of transition states.
Contributed by: Elizabeth Greenhalgh, Amanda Bischoff, and Matthew Sigman, University of Utah, 2015
Introductory PPT on Metal Carbonyls having its' classification,structure and applications.This is a basic level PPT specially prepared for UG/PG Chemistry students.
It contains what are the shift reagents, and how they will use in NMR spectroscopy. It includes lanthanide shift reagents and their effect using NMR spectroscopy. It has mostly used shift reagents like Europium and their importance. paramagnetic species that affect the NMR spectra are also explained in detail. What are contact shift and pseudo-contact shift also explained. It contains what are the chiral shift reagent, and the advantages, and disadvantages of lanthanide shift reagents. Reference books are also included.
THE PERICYCLIC REACTION THE MOST COMMON TOPIC INCLUDE THE SYLLABUS OF MANY SCIENCE STUDY INCLUDING BSC, MSC , PHARMA STUDY, AND MORE HENCE WE ARE COVERED ALL THE DATA OF IT HOPE THIS WILL MAKE READER EASY.
An overview of the use of the Marcus Theory to calculate the energies of transition states.
Contributed by: Elizabeth Greenhalgh, Amanda Bischoff, and Matthew Sigman, University of Utah, 2015
It would be use full to All Needy People. It involve information about NMR Spectroscopy ( a spectroscopic techniques), factors influencing , proton NMR and their applications of NMR as well as Nuclear magnetic imaging.
Longifolene is common naturally occurring, oily liquid hydrocarbon found in the high boiling fraction of certain pine resins.
Juvabione is a terpene- derived-keto-ester that has been isolated from plant sources.
Morphine is a major component of opium,it is isolated from poppy straw of the opium poppy.
Graphene is a single layer of carbon from the graphite.
Graphene is the strongest and the thinnest material known to exist.
Graphene is a 2- dimensional network of carbon atom. It is more efficient than silicon transistors. It can run at higher frequency. It is transparent in nature.
Conducting polymers have extended p-orbital system, through which electrons can be moved from one end to another and of polymer. Also, when a polymer is doped, there are changes in it due to resonance the charge can drift through the chain, and generating the conductivity.
Alkenes by absorption of light activated to higher energy singlet & triplet state and undergoes chemical reaction. These reactions are mainly:- 1. Cis - trans isomerization
2. Dimerization
3. Cycloaddition
Hypervalent refers to the main group elements that breaks the octet rule and firmly has more than right electrons in it's valence shell. These are non - metallic oxidation reagents.
Polymer supported Catalysts are in the form of network polymers in the form of beads.these polymers support can easily be recycled at the end the reaction mixture . It facilitates the purification process and isolation.
Biocatalysts are substance which alters to promote the reaction and a substance especially an enzyme, that initiates or modified the rate of chemical reaction.
Conducting polymers are those polymers which conduct electricity due to extended P- orbital system. Due to this extension of P orbital electrons can move from one end to another end of the polymer.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.
NMR Shift reagents
1. CONTENTS
• Introduction
• Why need of NMR shift reagents
• Resolving problem of signal overlap
• History of lanthanide shift reagents
• Mechanism of inducement of chemical
shift
• Interaction of chemical shift reagents
Advantages
• Disadvantages
• Conclusion
• References
2. INTRODUCTION
• Nuclear magnetic resonance spectroscopy (NMR) is
the most powerful tool for organic and
organometallic compound determination.
• Structures can be determined using this technique.
• In general NMR gives information about the number
of magnetically distinct atoms of the specific nuclei
under study, as well as information regarding the
nature of the immediate environment surrounding
each nuclei.
• Because hydrogen and carbon are the major
components of organic and organometallic
compounds, proton (1H) NMR and carbon-13 (13C)
NMR are the most useful nuclei to observe.
3. • Not all the protons experience resonance at the
same frequency in a 1H NMR, so it is possible to
differentiate between them.
• This diversity is due to the existence of a
different electronic environment around
chemically different nuclei.
• Under an external magnetic field (B0), the
electrons in the valence shell are affected; they
start to circulate generating a magnetic field,
which is apposite to the applied magnetic field.
This effect is called diamagnetic shielding or
diamagnetic anisotropy
4. Why need of nmr shift reagents
• The greater the electron density around one
specific nucleus, the greater will be the induced
field that opposes the applied field, and this will
result in a different resonance frequency.
• The identification of protons is simple, however,
the NMR technique has a relatively low sensitivity
of proton chemical shifts to changes in the
chemical and stereochemical environment; as a
consequence the resonance of chemically
similar proton overlap .
5. Methods for resolving problem of signal
overlap
• use of higher frequency spectrometers
• use of shift reagents - aromatic
solvents
• lanthanide complexes
6. History of lanthanide shift reagents
• The first significant induced chemical shift using
paramagnetic ions was reported in 1969 by Conrad
Hinckley , where he used bispyridine adduct of
tris(2,2,6,6-tetramethylhepta-3,5-
dionato)europium(III) (Eu(tmhd)3), better known as
Eu(dpm)3, where dpm is dipivaloyl- methanato.
• Hinckley used Eu(tmhd)3 on the 1H NMR spectrum of
cholesterol from 347 – 2 Hz.
• Hinckley ‘s this new chemical method to improve the
resolution of the NMR spectrum was the stepping-
stone for the work of Jeremy Sanders and Dudley
Williams .
7. Mechanism of inducement of
chemical shift
• Lanthanide atoms are Lewis acids, and because of that,
they have the ability to cause chemical shift by the
interaction with the basic sites in the molecules.
• Lanthanide metals are especially effective over other
metals because there is a significant delocalization of
the unpaired f electrons onto the substrate as a
consequence of unpaired electrons in the f shell of the
lanthanide.
• The lanthanide metal in the complexes interacts with the
relatively basic lone pair of electrons of aldehydes,
alcohols, ketones, amines and other functional groups
within the molecule that have a relative basic lone pair of
electrons, resulting in a NMR spectral simplification.
8. There are two possible mechanisms by
which a shift can occur
SHIFT BY CONTACT
Transfer of electron spin
density via covalent bond
formation from the
lanthanide metal ion to
the associated nuclei.
SHIFT BY
PSUEDOCONTACT
Magnetic effects of the
unpaired electron
magnetic moment causes
the pseudocontact shift.
9. • Lanthanide complexes give shifts primarily by the
pseudocontact mechanism.
• Principal factor that influence the shift of a
specific NMR peak is the distance between the
metal ion and the proton; the shorter the
distance, the greater the shift obtained
• Direction of the shift depends on the lanthanide
complex used. The complexes that produce a shift to a
lower field (downfield) are the ones containing erbium,
europium, thulium and ytterbium, while complexes
with cerium, neodymium, holmium, praseodymium,
samarium and terbium, shift resonances to higher field.
10. Interaction of chemical shift reagents::
Lanthanide complexes interact with a relatively basic pair
of electrons ( an unshared pair ) which can coordinate
with Eu+3. Typically, aldehydes, ketones, alcohols, thiols,
ethers and amines all interact.
11. Example-
The spectra of 1- hexanol:
In the absence of shift
reagent, the spectrum
shown Only the triplet
of the terminal methyl
group the triplet of the
methylene group next
to the hydroxyl are
resolved in the spectrum.
The protons
(aside from O-H) are
found together in a broad,
unresolved group. With the
shift reagent added each
of the methylene groups
is clearly separated and
is resolved into proper
multiplet structure.
12.
13. Advantages of using chemical shift reagents:
•Gives spectra which are much easier to
interpret.
•No chemical manipulation of the sample is
required with the use of shift reagents.
•More easily obtained
•Identifying enantiomeric mixtures in solution
14. disadvantage:
• Shift reagents cause a small
amount of line broadening
At high shift reagent concentrations this
problem becomes serious, but at most useful
concentrations the amount of broadening is
tolerable .
15. Conclusion
Thus the chemical shift reagents and solvent
induced shifts have their application in resolving
the NMR spectra of complex structures by
inducing shifts with respect to reference
compound. Thus useful in interpretation of
structures of complex organic compounds.
16. REFERENCES
• Donald L.pavia, Gary M.Lampman, Georges S.Kriz , Introduction to
spectroscopy , 3 rd edition, printed in the United States Of America,
P.322-323, 109-110.
• William Kemp, organic spectroscopy , 3 rd edition, printed by
replica press ltd., India P.102-106, 131-133, 169-170.
• C. C. Hinckley, J. Am. Chem. Soc., 1969, 91, 5160.
• file:///F:/NMR%20reagents/introduction.xhtml
•Edwin Becker, High Resolution NMR 3rd Edition