5.2 Chemical Shift
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Annual Report 2013-2014
ANNUAL REPORT 2013 – 14 One Hundred and Fifth Year Indian Institute of Science Bangalore - 560 012 i ii Contents Page No Page No Preface 5.3 Departmental Seminars and IISc at a glance Colloquia 120 5.4 Visitors 120 1. The Institute 1-3 5.5 Faculty: Other Professional 1.1 Court 1 Services 121 1.2 Council 2 5.6 Outreach 121 1.3 Finance Committee 3 5.7 International Relations Cell 121 1.4 Senate 3 1.5 Faculties 3 6. Continuing Education 123-124 2. Staff 4-18 7. Sponsored Research, Scientific & 2.1 Listing 4 Industrial Consultancy 125-164 2.2 Changes 12 7.1 Centre for Sponsored Schemes 2.3 Awards/Distinctions 12 & Projects 125 7.2 Centre for Scientific & Industrial 3. Students 19-25 Consultancy 155 3.1 Admissions & On Roll 19 7.3 Intellectual Property Cell 162 3.2 SC/ST Students 19 7.4 Society for Innovation & 3.3 Scholarships/Fellowships 19 Development 163 3.4 Assistance Programme 19 7.5 Advanced Bio-residue Energy 3.5 Students Council 19 Technologies Society 164 3.6 Hostels 19 3.7 Award of Medals 19 8. Central Facilities 165-168 3.8 Placement 21 8.1 Infrastructure - Buildings 165 8.2 Activities 166 4. Research and Teaching 26-116 8.2.1 Official Language Unit 166 4.1 Research Highlights 26 8.2.2 SC/ST Cell 166 4.1.1 Biological Sciences 26 8.2.3 Counselling and Support Centre 167 4.1.2 Chemical Sciences 35 8.3 Women’s Cell 167 4.1.3 Electrical Sciences 46 8.4 Public Information Office 167 4.1.4 Mechanical Sciences 57 8.5 Alumni Association 167 4.1.5 Physical & Mathematical Sciences 75 8.6 Professional Societies 168 4.1.6 Centres under Director 91 4.2. -
4 Nuclear Magnetic Resonance
Chapter 4, page 1 4 Nuclear Magnetic Resonance Pieter Zeeman observed in 1896 the splitting of optical spectral lines in the field of an electromagnet. Since then, the splitting of energy levels proportional to an external magnetic field has been called the "Zeeman effect". The "Zeeman resonance effect" causes magnetic resonances which are classified under radio frequency spectroscopy (rf spectroscopy). In these resonances, the transitions between two branches of a single energy level split in an external magnetic field are measured in the megahertz and gigahertz range. In 1944, Jevgeni Konstantinovitch Savoiski discovered electron paramagnetic resonance. Shortly thereafter in 1945, nuclear magnetic resonance was demonstrated almost simultaneously in Boston by Edward Mills Purcell and in Stanford by Felix Bloch. Nuclear magnetic resonance was sometimes called nuclear induction or paramagnetic nuclear resonance. It is generally abbreviated to NMR. So as not to scare prospective patients in medicine, reference to the "nuclear" character of NMR is dropped and the magnetic resonance based imaging systems (scanner) found in hospitals are simply referred to as "magnetic resonance imaging" (MRI). 4.1 The Nuclear Resonance Effect Many atomic nuclei have spin, characterized by the nuclear spin quantum number I. The absolute value of the spin angular momentum is L =+h II(1). (4.01) The component in the direction of an applied field is Lz = Iz h ≡ m h. (4.02) The external field is usually defined along the z-direction. The magnetic quantum number is symbolized by Iz or m and can have 2I +1 values: Iz ≡ m = −I, −I+1, ..., I−1, I. -
Ditellurides
Molecules 2010, 15, 1466-1472; doi:10.3390/molecules15031466 OPEN ACCESS molecules ISSN 1420-3049 www.mdpi.com/journal/molecules Article Novel Oxidative Ring Opening Reaction of 1H-Isotelluro- chromenes to Bis(o-formylstyryl) Ditellurides Haruki Sashida 1,*, Hirohito Satoh 1, Kazuo Ohyanagi 2 and Mamoru Kaname 1 1 Faculty of Pharmaceutical Sciences, Hokuriku University, Kanagawa-machi, Kanazawa 920-1181, Japan; E-Mail: [email protected] (M.K.) 2 Faculty of Pharmacy, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan; E-Mail: [email protected] (K.O.) * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +81-76-229-6211; Fax: +81-76-229-2781. Received: 5 January 2010; in revised form: 2 February 2010 / Accepted: 5 March 2010 / Published: 9 March 2010 Abstract: The oxidation of 1-unsubstituted or 1-phenyl-1H-isotellurochromenes with m-chloroperbenzoic acid (mCPBA) in CHCl3 resulted in a ring opening reaction to produce as the sole products the corresponding o-formyl or benzoyl distyryl ditellurides, which were also produced by the hydrolysis of the 2-benzotelluropyrylium salts readily prepared from the parent isotellurochromene. Keywords: isotellurochromene; mCPBA oxidation; 2-benzotelluropyrylium salt; distyryl ditelluride 1. Introduction The preparation and investigation of the reactions of new tellurium-containing heterocycles have lately attracted increasing interest in the fields of both heterocyclic [1–3] and organotellurium chemistry [4–8]. We have been studying the syntheses and reactions of the novel tellurium- or selenium-containing heterocyclic compounds over the past twenty years. -
Effect of Electronegative Elements on the NMR Chemical Shift in Some Simple R-X Organic Compounds
IOSR Journal of Applied Physics (IOSR-JAP) e-ISSN: 2278-4861.Volume 6, Issue 4 Ver. III (Jul-Aug. 2014), PP 45-56 www.iosrjournals.org Effect of electronegative elements on the NMR chemical shift in some simple R-X organic compounds Muhammad A. AL-Jalali1, Yahia M. Mahzia2 1Physics Department, Faculty of Science, Taif University, Taif, AL-Haweiah, , P. O. Box 888, Zip code 21974, Kingdom of Saudi Arabia 2Physics Department, Faculty of Science, Damascus University, Damascus, Syrian Arab Republic. Abstract: Organic halides and other organic compounds that contain electronegative elements, have a strong chemical shift and a brilliant NMR spectrum will prevail. Relationship between 1H, 13C NMR chemical shift and Electronegativity in some simple R-X organic compounds (X=F, Cl, Br, I, O, H, ...R=CH3 or CH3-CH2-) give nonlinear equation, as well as a power series equation appears between nuclear magnetogyric ratio, magnetic shielding constant and chemical shift, which are not included in the theoretical expressions. More investigations required to remove the discrepancy between the theoretical and the experimental results. Keywords: Electronegativity, chemical shift, shielding constant, magnetogyric ratio. I. Introduction Nuclear magnetic resonance, or NMR is a physical phenomenon was observed in 1945[1,2], which occurs when the nuclei of certain atoms, firstly, subject to nuclear Zeeman effect[3,4,5]will Precession with the Larmor frequency [6, 7]. Secondly, exposed to an oscillating electromagnetic field (radio waves), then if the radio wave frequency exactly matches the precession frequency, the resonance phenomenon will happen and this is the so-called nuclear magnetic resonance. However, experimentally, it has been noticed [8, 9, 10] that a nucleus may have a different resonant frequency for a given applied magnetic field in different chemical compounds, this difference in resonant frequency is called the chemical shift or sometimes fine structure. -
The Chemical Shift Chem 117 the Chemical Shift Key Questions (1) What Controls Proton Chemical Shifts? Eugene E
E. Kwan Lecture 2: The Chemical Shift Chem 117 The Chemical Shift Key Questions (1) What controls proton chemical shifts? Eugene E. Kwan January 26, 2012. H H H H 0.86 ppm 5.28 2.88 Br Scope of Lecture 16.4 proton chemical problem shift trends diamagnetic vs. (2) What controls carbon chemical shifts? solving paramagnetic O O shielding O CH2 H C OH the chemical 3 H3C CH3 basic DEPT 49.2 49.2 40.5 69.2 and COSY shift H-bonding and solvent (3) What are COSY and DEPT? What useful information effects spin-orbit coupling, can they give about a structure? carbon chemical effect of unsaturation shift trends 123 Helpful References 10 0 1. Nuclear Magnetic Resonance Spectroscopy... Lambert, J.B.; 1 Mazzola, E.P. Prentice-Hall, 2004. (Chapter 3) 2 2. The ABCs of FT-NMR Roberts, J.D. University Science Books, 2000. (Chapter 10) 3 3. Spectrometric Identification of Organic Compounds (7th ed.) Silverstein, R.M.; Webster, F.X.; Kiemle, D.J. Wiley, 2005. (useful charts in the appendices of chapters 2-4) 10 4. Organic Structural Spectroscopy Lambert, J.B.; Shurvell, H.F.; Lightner, D.A.; Cooks, R.G. Prentice-Hall, 1998. I thank Professors William F. Reynolds (Toronto) and Gene Mazzola (Maryland/FDA) for providing some useful 5. Organic Structure Analysis Crews, P. Rodriguez, J.; Jaspars, material for this lecture. The section on chemical shifts M. Oxford University Press, 1998. is based on the discussion in Chapter 3 of reference 1. E. Kwan Lecture 2: The Chemical Shift Chem 117 Proton Chemical Shifts Clearly, the regions overlap: reference: Lambert and Mazzola, Chapter 3. -
NMR Chemical Shifts of Common Laboratory Solvents As Trace Impurities
7512 J. Org. Chem. 1997, 62, 7512-7515 NMR Chemical Shifts of Common Laboratory Solvents as Trace Impurities Hugo E. Gottlieb,* Vadim Kotlyar, and Abraham Nudelman* Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900, Israel Received June 27, 1997 In the course of the routine use of NMR as an aid for organic chemistry, a day-to-day problem is the identifica- tion of signals deriving from common contaminants (water, solvents, stabilizers, oils) in less-than-analyti- cally-pure samples. This data may be available in the literature, but the time involved in searching for it may be considerable. Another issue is the concentration dependence of chemical shifts (especially 1H); results obtained two or three decades ago usually refer to much Figure 1. Chemical shift of HDO as a function of tempera- more concentrated samples, and run at lower magnetic ture. fields, than today’s practice. 1 13 We therefore decided to collect H and C chemical dependent (vide infra). Also, any potential hydrogen- shifts of what are, in our experience, the most popular bond acceptor will tend to shift the water signal down- “extra peaks” in a variety of commonly used NMR field; this is particularly true for nonpolar solvents. In solvents, in the hope that this will be of assistance to contrast, in e.g. DMSO the water is already strongly the practicing chemist. hydrogen-bonded to the solvent, and solutes have only a negligible effect on its chemical shift. This is also true Experimental Section for D2O; the chemical shift of the residual HDO is very NMR spectra were taken in a Bruker DPX-300 instrument temperature-dependent (vide infra) but, maybe counter- (300.1 and 75.5 MHz for 1H and 13C, respectively). -
Durham E-Theses
Durham E-Theses A spectroscopic study of some halogeno-complexes of tellurium (IV) Gorrell, Ian Barnes How to cite: Gorrell, Ian Barnes (1983) A spectroscopic study of some halogeno-complexes of tellurium (IV), Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/7890/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk A SPECTROSCOPIC STUDY OF SOME HALOGENO- COMPLEXES OF TELLURIUM (IV) by Ian Barnes Gorrell A thesis submitted in part fulfilment of the requirements for the degree of Master of Science in the University of Durham. The copyright of this thesis rests with the author. April 19 8 3 No quotation from it should be published without his prior written consent and information derived from it should be acknowledged. -5. OFC. 1983 TO MY MOTHER and MY FATHER1 S MEMORY' iii ACKNOWLEDGMENTS I wish to express my gratitude towards the late Professor T.C. -
Article Is Available Online Is One of the Most Comprehensive Ways to Envision Such at Doi:10.5194/Bg-13-2257-2016-Supplement
Biogeosciences, 13, 2257–2277, 2016 www.biogeosciences.net/13/2257/2016/ doi:10.5194/bg-13-2257-2016 © Author(s) 2016. CC Attribution 3.0 License. Molecular characterization of dissolved organic matter from subtropical wetlands: a comparative study through the analysis of optical properties, NMR and FTICR/MS Norbert Hertkorn1, Mourad Harir1, Kaelin M. Cawley2, Philippe Schmitt-Kopplin1, and Rudolf Jaffé2 1Helmholtz Zentrum München, German Research Center for Environmental Health, Research Unit Analytical Biogeochemistry (BGC), Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany 2Southeast Environmental Research Center, and Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199, USA Correspondence to: Rudolf Jaffé (jaffer@fiu.edu) Received: 23 July 2015 – Published in Biogeosciences Discuss.: 25 August 2015 Revised: 22 December 2015 – Accepted: 7 February 2016 – Published: 19 April 2016 Abstract. Wetlands provide quintessential ecosystem ser- relative disparity was largest between the Everglades long- vices such as maintenance of water quality, water supply and short-hydroperiod samples, whereas Pantanal and Oka- and biodiversity, among others; however, wetlands are also vango samples were more alike among themselves. Other- among the most threatened ecosystems worldwide. Natural wise, molecular divergence was most obvious in the case dissolved organic matter (DOM) is an abundant and criti- of unsaturated protons (δH > 5 ppm). 2-D NMR spectroscopy cal component in wetland biogeochemistry. This study de- for a particular sample revealed a large richness of aliphatic scribes the first detailed, comparative, molecular characteri- and unsaturated substructures, likely derived from microbial zation of DOM in subtropical, pulsed, wetlands, namely the sources such as periphyton in the Everglades. -
Measuring T1 and T2 Relaxation Times
Relaxation Measurements Two Relaxation Mechanisms 90° pulse T1: Spin‐lattice or longitudinal relaxation is the average lifetime of the nuclei in the higher spin state T2: Spin‐spin or transverse relaxation corresponds to a de‐coherence of the transverse nuclear spin magnetization Spin‐Lattice Relaxation Time or T1 • Any factor which slows molecular motion (e.g. increasing solution viscosity, aggregation, or rigidifying the molecule) shortens the spin‐lattice relaxation time • A short T1 favors sensitivity but too short can result in line broadening and degradation of resolution since T2 cannot be longer than T1 • 3 principal magnetic interactions that contribute to T1 relaxation of spin ½ nuclei: o Dipole‐dipole interaction ‐ the nucleus experiences a fluctuating field due to the motions of neighboring dipoles, unpaired electrons, or other nuclei o Chemical shift anisotropy ‐ chemical shielding of the nucleus is a function of molecular orientation with respect to B0 field direction o Spin rotation interaction –small magnetic fields are induced at the nucleus as a molecule reorients; this field fluctuates because the motions are not uniform but proceed by a series of small jumps • Small amounts of paramagnetic substances speed up relaxation • Inversion recovery experiment measures T1 T1 Measurement: Inversion Recovery Parameters to note & Optimize • To change the value of the delay, d7, a variable delay list must be created. • In the acquisition parameters a VDLIST can be generated which contains values that typically cover a time range which extends past vdlist the expected T1 value. 0.05 0.5 Iz = I0(1‐2exp(‐d7/T1) 1.0 1.5 ln(I0‐Iz) = ln(2I0)‐d7/T1 2 Tnull = T1*ln2 4 6 8 Spin‐Spin Relaxation Time or T2 • T1 = T2 when molecular tumbling is fast compared with the Larmor frequency; this is the condition for small molecules. -
NMR Spectroscopy
NMR spectroscopy • Not a single technique but a large set of related techniques • “simple” 1H-NMR • 13C NMR • 2D experiments 1 Nuclear Spin Angular momentum of spinning charge described by quantum spin number “I” Intrinsic magnitude of generated dipole = I = 0, 1/2, 1, 3/2… Spinning nucleus generates a magnetic dipole (µ) Criteria for spin: Atomic mass Atomic # I Example even even 0 12C, 16O, 34S odd odd or even half integer 1H (1/2); 13C (1/2); 15N (3/2) even odd integer 14N (1), 2H (1) Spin ½ nuclei in magnetic field (e.g. 1H and 13C) In the absence of a magnetic field, these spins have the same energy and are randomly aligned #orientations with respect to an applied B = 2I+1 B0 In an external magnetic field (B0) spin ½ can align with the magnetic field or against it (2)(1/2)+1 = 2 ΔE energy difference magnetogyric ratio hγB0 γB0 γ ΔE= ν= resonant frequency 2π 2π ν The difference in energy between the two spin states depends on B: ΔE increases with B β-spin hν ΔE depends on B, so the frequency of light needed to flip the nuclei will depend on Energy B α-spin applied magnetic field (B) 4 Common NMR active nuclei 2πµ γ = hI 7 -1 -1 Nucleus Natural Abundance γ (10 radT s ) 1H 99.9844 26 753 13C 1.108 6 728 19F 100 25 179 31P 100 10 840 1 13 νC = 0.25νΗ For a B0 where ν=200 MHz ( H) ν ≈ 50 MHz ( C) Energy difference and population The number of nuclei in the two states α and β are determined by Boltzmann distribution: N upper = e-ΔE/kT Nlower Since the α-spin state is lower in energy, it is more populated (more nuclei have α than β). -
Stereoselective Synthesis of 2-Deoxyoligosaccharides New
UNIVERSITAT ROVIRA I VIRGILI STEREOSELECTIVE SYNTHESIS OF 2-DEOXYOLIGOSACCHARIDES.NEW APRROACHES TO THE SYNTHESIS OF DIGITOXIN AND P-57 Andrea Köver 978-84-691-9523-9 /DL: T-1261-2008 Departamento de Química Analítica y Química Orgánica Stereoselective Synthesis of 2-Deoxyoligosaccharides ─ New Approaches to the Synthesis of Digitoxin and P57 Memoria presentada por Andrea Kövér Para optar al título de Doctor en Química Tarragona, Abril 2008 UNIVERSITAT ROVIRA I VIRGILI STEREOSELECTIVE SYNTHESIS OF 2-DEOXYOLIGOSACCHARIDES.NEW APRROACHES TO THE SYNTHESIS OF DIGITOXIN AND P-57 Andrea Köver 978-84-691-9523-9 /DL: T-1261-2008 UNIVERSITAT ROVIRA I VIRGILI STEREOSELECTIVE SYNTHESIS OF 2-DEOXYOLIGOSACCHARIDES.NEW APRROACHES TO THE SYNTHESIS OF DIGITOXIN AND P-57 Andrea Köver 978-84-691-9523-9 /DL: T-1261-2008 Departamento de Química Analítica y Química Orgánica Química Analítica y Química Orgánica de la Universitat Rovira i Virgili. CERTIFICAN: Que el trabajo titulado: “Stereoselective Synthesis of 2-Deoxyoligosaccharides ─ New Approaches to the Synthesis of Digitoxin and P57” presentado por Andrea Kövér para optar al grado de Doctor, ha estado realizado bajo su inmediata dirección en los laboratorios de Química Orgánica del Departamento de Química Analítica y Química Orgánica de la Universitat Rovira i Virgili. Tarragona, Abril de 2008 Sergio Castillón Miranda Yolanda Díaz Giménez i UNIVERSITAT ROVIRA I VIRGILI STEREOSELECTIVE SYNTHESIS OF 2-DEOXYOLIGOSACCHARIDES.NEW APRROACHES TO THE SYNTHESIS OF DIGITOXIN AND P-57 Andrea Köver 978-84-691-9523-9 -
VU Research Portal
VU Research Portal The Role of Selenium in Glutathione Peroxidase Bortoli, M. 2019 document version Publisher's PDF, also known as Version of record Link to publication in VU Research Portal citation for published version (APA) Bortoli, M. (2019). The Role of Selenium in Glutathione Peroxidase: Insights from Molecular Modeling. General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. E-mail address: [email protected] Download date: 23. Sep. 2021 VRIJE UNIVERSITEIT UNIVERSITÀ DEGLI STUDI DI PADOVA THE ROLE OF SELENIUM IN GLUTATHIONE PEROXIDASE: INSIGHTS FROM MOLECULAR MODELING ACADEMISCH PROEFSCHRIFT ter verkrijging van de graad Doctor of Philosophy aan de Vrije Universiteit Amsterdam, op gezag van de rector magnificus prof.dr. V. Subramaniam en Dottore di Ricerca aan de Università degli Studi di Padova op gezag van de rector magnificus prof.dr. Rosario Rizzuto, in het openbaar te verdedigen ten overstaan van de promotiecommissie van de Faculteit der Bètawetenschappen op woensdag 17 april 2019 om 11.45 uur in de aula van de universiteit, De Boelelaan 1105 door Marco Bortoli geboren te Marostica, Italië promotoren: prof.dr.