9Be nuclear magnetic resonance spectroscopy trends in discrete complexes: an update

Abstract9Be solution NMR spectroscopy is a useful tool for the characterisation of beryllium complexes. An updated comprehensive table of the 9Be NMR chemical shifts of beryllium complexes in solution is presented. The recent additions span a greater range of chemical shifts than those previously reported, and more overlap is observed between the chemical shift regions of four-coordinate complexes and those with lower coordination numbers. Four-coordinate beryllium species have smaller ω1/2 values than the two- and three-coordinate species due to their higher order symmetry. In contrast to previous studies, no clear relationship is observed between chemical shift and the size and number of chelate rings.

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The characterization of primary, secondary, and tertiary vanadate alkyl esters by 51V nuclear magnetic resonance spectroscopy

Canadian Journal of Chemistry ◽

10.1139/v88-403 ◽

1988 ◽

Vol 66 (10) ◽

pp. 2570-2574 ◽

Cited By ~ 24

Author(s):

Alan S. Tracey ◽

Michael J. Gresser

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Chemical Shift ◽

Magnetic Resonance Spectroscopy ◽

Nuclear Magnetic Resonance Spectroscopy ◽

Chemical Shifts ◽

Hydroxyl Group ◽

Resonance Spectroscopy ◽

Low Field ◽

Nuclear Magnetic

A variety of alkyl vanadates has been studied by 51V nuclear magnetic resonance spectroscopy. It was found that the equilibrium constant for condensation of vanadate with alcohols is insensitive to whether the hydroxyl group is primary, secondary, or tertiary. These products, however, have characteristic vanadium chemical shifts that allow assignment of nmr signals to the appropriate ester. It was also found that chemical shifts are additive in the sense that the chemical shifts of the esters ROVO3H− are one half the chemical shift of the diesters (RO)2VO2− when those shifts are given relative to −559 ppm. This effect is independent of whether the signals are to high or low field of −559 ppm and the additivity extends to mixed ligand systems. This value of −559 ppm is close but not equal to the chemical shift of the vanadate monoanion, H2VO41−, which is at −561 ppm. These results are at variance with arguments concerning the effects of ligand bulkiness on chemical shifts of vanadium(V) complexes.

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The structures and reactions of stannylene acetals from carbohydrate-derived trans-diols. Part I. In the absence of added nucleophiles

Canadian Journal of Chemistry ◽

10.1139/v90-158 ◽

1990 ◽

Vol 68 (7) ◽

pp. 1007-1019 ◽

Cited By ~ 32

Author(s):

T. Bruce Grindley ◽

Rasiah Thangarasa

Keyword(s):

Nuclear Magnetic Resonance ◽

Nmr Spectroscopy ◽

Magnetic Resonance ◽

Magnetic Resonance Spectroscopy ◽

Chemical Shifts ◽

The Other ◽

Resonance Spectroscopy ◽

Pyranose Ring ◽

Regioselective Reactions ◽

C Nmr

Di-n-butylstannylene acetals of benzyl 4,6-O-benzylidene-α- and -β-D-glucopyranoside and galactopyranoside have been prepared and studied in solution by 1H, 13C, and 119Sn nuclear magnetic resonance spectroscopy. The species present in solution have been identified from the 119Sn nmr spectral data, by comparison of the 13C nmr chemical shifts of the stannylene acetals and their precursor diols and also by analysis of the products of reactions performed without added nucleophiles. The orientations of the two substituents on the carbons in the pyranose ring attached to the carbons in the stannylene ring determine the structures adopted by the stannylene acetal in solution. If one substituent is axial and the other equatorial, the stannylene acetal exists as a single symmetrical dimer in which the two oxygen atoms in the two 1,3,2-dioxastannolane rings adjacent to the axial substituents are dicoordinate. A stannylene acetal with two adjacent equatorial substituents exists as a non-interconverting mixture of dimers; one with two adjacent axial substituents is present as a rapidly interconverting mixture of dimers, trimers, and tetramers. Benzoylation and benzylation of the latter two types of stannylene acetals have been performed and have been shown to be only slightly regioselective in contrast to the known highly regioselective reactions of the first type. Only when single dimers are present are regiospecific or highly regioselective reactions obtained. The causes of the variation in the species present and of the reaction regioselectivity for different stannylene acetals are discussed. Keywords: stannylene acetals, 1,3,2-dioxastannolanes, 119Sn NMR spectroscopy, regioselective reactions, carbohydrates.

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About Nuclear Magnetic Resonance Spectroscopy

Bulletin of Science and Practice ◽

10.33619/2414-2948/42/02 ◽

2019 ◽

Vol 5 (5) ◽

pp. 19-24

Author(s):

V. Shvannikov

Keyword(s):

Organic Chemistry ◽

Nuclear Magnetic Resonance ◽

Organic Matter ◽

Nmr Spectroscopy ◽

Magnetic Resonance ◽

Chemical Shift ◽

Resonance Spectroscopy ◽

General Terms ◽

Synthetic Chemist ◽

Main Components

The paper deals with the main components of NMR spectroscopy, namely: terminology (chemical shift, multiplicity, and so on) and some examples of software additions (COSY, HECTOR). The theme of this work is aimed at students in the profile of organic chemistry, it allows you to get acquainted with the phenomenon of NMR (in General terms) and decoding spectra without deepening into quantum chemistry and physics. This improves communication and minimizes misunderstandings between the synthetic chemist and the spectroscopic chemist, as this method is one of the most commonly used in determining the structure of organic matter (does not violate the integrity of the carbon skeleton and prevents fragmentation).

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1H and 13C Nuclear Magnetic Resonance Spectroscopy of Some Derivatives of Nitro Sugars

Canadian Journal of Chemistry ◽

10.1139/v73-268 ◽

1973 ◽

Vol 51 (11) ◽

pp. 1797-1800 ◽

Cited By ~ 2

Author(s):

N. Gurudata ◽

F. J. M. Rajabalee

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Chemical Shift ◽

Magnetic Resonance Spectroscopy ◽

Nuclear Magnetic Resonance Spectroscopy ◽

Addition Reaction ◽

Chemical Shifts ◽

Resonance Spectroscopy ◽

13C Nuclear Magnetic Resonance ◽

Derivatives Of

Eight 2,3-dideoxy-2-amino-3-nitrosugar derivatives have been obtained by an elimination–addition reaction on the α and β anomers of methyl-4,6-O-benzylidene-3-deoxy-3-nitro-glucopyranoside-2-acetate. P.m.r. is used to show that the compounds exist in the CE conformation. 13C.m.r. data are presented for three anomeric pairs. Trends in the C-13 chemical shifts are found to be similar to those reported in other studies of carbohydrates. Exceptions in direction and magnitude of chemical shift differences are discussed.

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Conformational analysis of ketoximes by the application of carbon-13 nuclear magnetic resonance spectroscopy

Canadian Journal of Chemistry ◽

10.1139/v78-315 ◽

1978 ◽

Vol 56 (14) ◽

pp. 1940-1946 ◽

Cited By ~ 32

Author(s):

Patrick Geneste ◽

Robert Durand ◽

Jean-Marc Kamenka ◽

Helmut Beierbeck ◽

Robert Martino ◽

...

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Chemical Shift ◽

Magnetic Resonance Spectroscopy ◽

Conformational Analysis ◽

Nuclear Magnetic Resonance Spectroscopy ◽

Dihedral Angle ◽

Chemical Shifts ◽

Resonance Spectroscopy ◽

Chemical Shift Difference

The carbon-13 chemical shifts for a number of relatively rigid ketoximes are presented. It is shown that the chemical shift difference, Δδ (syn—anti), for the carbons α to the oxime carbon depends on the dihedral angle between the C=N and Cα—H bonds. This stereochemical dependence is then used to determine the preferred conformation of substituted cyclohexanone oximes.

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Biological NMR Spectroscopy

10.1093/oso/9780195094688.001.0001 ◽

1997 ◽

Keyword(s):

Nuclear Magnetic Resonance ◽

Nmr Spectroscopy ◽

Magnetic Resonance ◽

Magnetic Resonance Spectroscopy ◽

State Of The Art ◽

Critical Assessment ◽

Resonance Spectroscopy ◽

History Of ◽

Structure Of Proteins

This book presents a critical assessment of progress on the use of nuclear magnetic resonance spectroscopy to determine the structure of proteins, including brief reviews of the history of the field along with coverage of current clinical and in vivo applications. The book, in honor of Oleg Jardetsky, one of the pioneers of the field, is edited by two of the most highly respected investigators using NMR, and features contributions by most of the leading workers in the field. It will be valued as a landmark publication that presents the state-of-the-art perspectives regarding one of today's most important technologies.

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Studies of specifically fluorinated carbohydrates. Part II. Nuclear magnetic resonance studies of pentopyranosyl fluoride derivatives

Canadian Journal of Chemistry ◽

10.1139/v69-002 ◽

1969 ◽

Vol 47 (1) ◽

pp. 19-30 ◽

Cited By ~ 59

Author(s):

L. D. Hall ◽

J. F. Manville

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Magnetic Resonance Spectroscopy ◽

Nuclear Magnetic Resonance Spectroscopy ◽

Chemical Shifts ◽

Coupling Constants ◽

Resonance Spectroscopy ◽

Magnetic Resonance Studies ◽

Conformational Model ◽

Nuclear Magnetic

Detailed studies, by 1H and 19F nuclear magnetic resonance spectroscopy, of a series of fully esterified pentopyranosyl fluorides, show that all such derivatives favor that conformer in which the fluorine substituent is axially oriented. This conclusion is supported by separate considerations of the vicinal and geminal19F–1H and 1H–1H coupling constants, of the long-range (4J) 1H–1H and 19F–1H coupling constants and of the 19F chemical shifts. The limitations of the above conformational model are discussed.

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Study of the biologically active acyclic ureas by nuclear magnetic resonance

Bulletin of the Karaganda University Chemistry series ◽

10.31489/2020ch4/60-74 ◽

2020 ◽

Vol 100 (4) ◽

pp. 60-74

Author(s):

А.А. Bakibaev ◽

◽

М.Zh. Sadvakassova ◽

V.S. Malkov ◽

R.Sh. Еrkasov ◽

...

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Functional Groups ◽

13C Nmr ◽

Nmr Spectra ◽

Chemical Shifts ◽

Biologically Active ◽

Resonance Spectroscopy ◽

13C Nmr Spectra ◽

Nuclear Magnetic

A wide variety of acyclic ureas comprising alkyl, arylalkyl, acyl, and aryl functional groups are investigated by nuclear magnetic resonance spectroscopy. In general, spectral characteristics of more than 130 substances based on acyclic ureas dissolved in deuterated dimethyl sulfoxide at room temperature are studied. The re-sults obtained based on the studies of 1H and 13C NMR spectra of urea and its N-alkyl-, N-arylalkyl-, N-aryl- and 1,3-diaryl derivatives are presented, and the effect of these functional groups on the chemical shifts in carbonyl and amide moieties in acyclic urea derivatives is discussed. An introduction of any type of substitu-ent (electron-withdrawing or electron-donating) into urea molecule is stated to result in a strong upfield shift in 13C NMR spectra relatively to unsubstituted urea. A strong sensitivity of NH protons to the presence of acyl and aryl groups in nuclear magnetic resonance spectra is pointed out. In some cases, qualitative depend-encies between the chemical shifts in the NMR spectra and the structure of the studied acyclic ureas are re-vealed. A summary of the results on chemical shifts in the NMR spectra of the investigated substances allows determining the ranges of chemical shift variations of the key protons and carbon atoms in acyclic ureas. The literature describing the synthesis procedures are provided. The results obtained significantly expand the methods of reliable identification of biologically active acyclic ureas and their metabolites that makes it promising to use NMR spectroscopy both in biochemistry and in clinical practice.

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Recent Advances in Solid-State Nuclear Magnetic Resonance Spectroscopy

Annual Review of Analytical Chemistry ◽

10.1146/annurev-anchem-061417-125852 ◽

2018 ◽

Vol 11 (1) ◽

pp. 485-508 ◽

Cited By ~ 15

Author(s):

Sharon E. Ashbrook ◽

John M. Griffin ◽

Karen E. Johnston

Keyword(s):

Nuclear Magnetic Resonance ◽

Solid State ◽

Nmr Spectroscopy ◽

Magnetic Resonance ◽

Solid State Nmr ◽

Spectral Lines ◽

Atomic Scale ◽

Resonance Spectroscopy ◽

Diverse Range ◽

Nuclear Magnetic

The sensitivity of nuclear magnetic resonance (NMR) spectroscopy to the local atomic-scale environment offers great potential for the characterization of a diverse range of solid materials. Despite offering more information than its solution-state counterpart, solid-state NMR has not yet achieved a similar level of recognition, owing to the anisotropic interactions that broaden the spectral lines and hinder the extraction of structural information. Here, we describe the methods available to improve the resolution of solid-state NMR spectra and the continuing research in this area. We also highlight areas of exciting new and future development, including recent interest in combining experiment with theoretical calculations, the rise of a range of polarization transfer techniques that provide significant sensitivity enhancements, and the progress of in situ measurements. We demonstrate the detailed information available when studying dynamic and disordered solids and discuss the future applications of solid-state NMR spectroscopy across the chemical sciences.

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