Spectroscopic Properties of a Series of Vinyl–Platinum Complexes

1973 ◽  
Vol 51 (14) ◽  
pp. 2243-2250 ◽  
Author(s):  
T. G. Appleton ◽  
M. H. Chisholm ◽  
H. C. Clark ◽  
L. E. Manzer
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Platinum Complexes ◽  
Spectroscopic Properties ◽  
Coupling Constants ◽  
Neutral Ligand ◽  
Coupling Constant ◽  
Vinyl Proton ◽  
Anionic Ligand ◽  
Nuclear Magnetic

Nuclear magnetic resonance, infrared, and Raman data are given for the series trans-PtRXQ2 and trans-[PtRQ2L]+, where [Formula: see text], Q = (PCH3)2C6H5, L = neutral ligand, and Z = anionic ligand. The coupling constants between 195Pt and the trifluoromethyl 19F nuclei and between 195Pt and the vinyl proton Hv both correlate linearly with [Formula: see text] for the corresponding methylplatinum complexes. The results are explained in terms of platinum hybridization in the Pt—C bond dominating the coupling constant.

Anisotropy of indirect spin–spin coupling constants from nuclear magnetic resonance powder patterns of rigid solids. 1J(31P,199Hg) in [HgP(o-tolyl)3(NO3)2]2

1988 ◽  
Vol 66 (8) ◽  
pp. 1821-1823 ◽  
Author(s):  
Glenn H. Penner ◽  
William P. Power ◽  
Roderick E. Wasylishen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Coupling Constant ◽  
Spin Coupling Constants ◽  
Fermi Contact ◽  
Spin Spin Coupling ◽  
Contact Mechanism ◽  
Nuclear Magnetic

The anisotropy of the indirect 31P,199Hg spin–spin coupling constant, ΔJ, in solid [HgP(o-tolyl)3(NO3)2]2 is obtained from an analysis of the 31P nuclear magnetic resonance powder pattern. The value of ΔJ, 5170 ± 250 Hz, is large and indicates that mechanisms other than the Fermi contact mechanism are important for this spin–spin coupling. The powder spectrum also indicates that the absolute sign of 1J(31P,199Hg) is positive.

Nuclear magnetic resonance studies. XI. Vinyl proton chemical shifts and coupling constants of some substituted styrenes

1967 ◽  
Vol 45 (7) ◽  
pp. 731-737 ◽  
Author(s):  
Gurudata ◽  
J. B. Stothers ◽  
J. D. Talman
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Spin Systems ◽  
Coupling Constants ◽  
Vinyl Proton ◽  
Magnetic Resonance Studies ◽  
Vinyl Carbon ◽  
Proton Chemical Shifts ◽  
Nuclear Magnetic

The proton spectra of the vinyl groups in a series of 23 substituted styrenes have been analyzed as ABC spin systems. The proton chemical shifts are compared with the previously reported shielding data for the corresponding vinyl carbon nuclei. The series includes 12 meta- and para-substituted examples and 10 ortho-substituted examples. The effects of steric inhibition of conjugation on the vinyl proton parameters for some 2,6-disubstituted derivatives are considered in detail.

Long-range 13C, 13C spin–spin coupling constants in anisole and some derivatives

1988 ◽  
Vol 66 (7) ◽  
pp. 1635-1640 ◽  
Author(s):  
Ted Schaefer ◽  
Glenn H. Penner
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Methoxy Group ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Coupling Constant ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling ◽  
Nuclear Magnetic

13C nuclear magnetic resonance chemical shifts and nJ(13C,13C) are reported for anisole and 16 of its derivatives, all enriched with 13C in the methoxyl group. 5J(13C,13C) is directly proportional to sin2θ, where θ is the angle by which the methoxy group twists about the C(1)—O bond. In acetone-d6 solution, 5J(C,C) is not observable for a number of 4-substituted anisoles, except for 1,4-dimethoxybenzene. For the latter, 5J(C,C) is compatible with a twofold barrier of 19.3 ± 1.1 kJ/mol hindering rotation about the C(1)—O bond. However, it is unlikely that the barrier is purely twofold in nature. The observed 5J(C,C) is also compatible with 10.5 and 6.0 kJ/mol for the twofold and fourfold components, respectively, implying a dynamical nuclear magnetic resonance barrier of less than 13 kJ/mol. While phase and solvent effects on the internal barrier in anisole are certainly substantial, it appears that a fourfold component must also be present. The apparent twofold barrier in 2,6-difluoroanisole is 5.4 ± 0.9 kJ/mol, based on 5J(C,C) and 6J(H-4,13C). The latter coupling constant is also reported for 1,2,3-trimethoxybenzene and used to deduce its conformation. The θ dependence of 3J(C,C) and 4J(C,C) is briefly discussed for symmetrical anisole derivatives. Differential 13C, 13C isotope shifts are reported for 1,4-dimethoxybenzene.

Long-range coupling constants for α-13C nuclei in phenyl-X-R (X = O,S,Se,Te) derivatives. Internal rotational information

1988 ◽  
Vol 66 (7) ◽  
pp. 1641-1646 ◽  
Author(s):  
Ted Schaefer ◽  
Glenn H. Penner
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Long Range ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Photoelectron Spectra ◽  
Side Chain ◽  
Coupling Constant ◽  
Stable Conformation ◽  
Nuclear Magnetic

The long-range spin–spin coupling constant over six bonds between the 19F nucleus and the 13C nucleus in the side chain,6J(C,F), is reported for 4—F—C6H4—X—R, where X = O, S and R = CH3, CH2CH3, CH(CH3)2 and C(CH3)3 and 6J(C,F) depends on sin2 θ, where θ is the angle by which the side chain twists out-of-plane about the [Formula: see text] bond. Expectation values of sin2 θ are obtained from 6J(C,F), yielding magnitudes of the apparent twofold barrier to rotation about the [Formula: see text] bond. In these terms, the most stable conformation is that for θ = 0° for all compounds, with the exception of R = C(CH3)3 and of X = S, R = CH(CH3)2; there is effectively free rotation about the [Formula: see text] bond in isopropyl 4-fluorophenyl sulfide in acetone-d6 solution. Good correlations exist between 6J(C,F) and a number of other molecular properties, including certain differences of ionization potentials of the molecular orbitals in the ethers. In particular, the chemical shifts of C-4 are correlated with 6J(C,F). Because 5J(C,C), the coupling constant involving C-4, also depends on sin2 θ, it is measured for the methyl and ethyl selenides and tellurides, as are other 13C,13C couplings involving a 13C nucleus in the side chain. The literature values for the 13C nuclear magnetic resonance chemical shifts in alkyl phenyl selenides and tellurides can be related to θ preferences and also allow estimates of the extrema in 5J(C,C). The resultant values of arcsin [Formula: see text] for R = CH3 are in good agreement with estimates of θ obtained from electron diffraction patterns, photoelectron spectra, and nuclear magnetic resonance in the nematic phase.

Conformational dynamics detected by nuclear magnetic resonance NOE values and J coupling constants

1988 ◽  
Vol 110 (11) ◽  
pp. 3393-3396 ◽  
Author(s):  
Horst. Kessler ◽  
Christian. Griesinger ◽  
Joerg. Lautz ◽  
Arndt. Mueller ◽  
Wilfred F. Van Gunsteren ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Conformational Dynamics ◽  
Coupling Constants ◽  
J Coupling ◽  
J Coupling Constants ◽  
Nuclear Magnetic

Studies of specifically fluorinated carbohydrates. Part I. Nuclear magnetic resonance studies of hexopyranosyl fluoride derivatives

1969 ◽  
Vol 47 (1) ◽  
pp. 1-17 ◽  
Author(s):  
L. D. Hall ◽  
J. F. Manville ◽  
N. S. Bhacca
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Angular Dependence ◽  
Chemical Shifts ◽  
Relative Orientation ◽  
Coupling Constants ◽  
Pyranose Ring ◽  
Spectral Parameters ◽  
Magnetic Resonance Studies ◽  
Nuclear Magnetic

A detailed study has been made of both the 1H and 19F nuclear magnetic resonance (n.m.r.) spectra of a series of hexopyranosyl fluoride derivatives. Some of the 1H spectra were measured at 220 MHz. The 1H spectral parameters define both the configuration and the conformation of each of these derivatives. Study of the 19F n.m.r. parameters revealed several stereospecific dependencies. The 19F chemical shifts depend upon, (a) the orientation of the fluorine substituent with respect to the pyranose ring and, (b) the relative orientation of other substituents attached to the ring; for acetoxy substituents, these configurational dependencies appear to be additive. The vicinal19F–1H coupling constants exhibit a marked angular dependence for which Jtrans = ca. 24 Hz whilst Jgauche = 1.0 to 1.5 Hz for [Formula: see text] and 7.5 to 12.6 Hz for [Formula: see text] The geminal19F–1H couplings depend on the orientation of the substituent at C-2; when this substituent is equatorial JF,H is ca. 53.5 Hz and when it is axial the value is ca. 49 Hz.

An estimate of the spin–spin coupling constant, 1J(1H,13C), in gaseous benzene

1996 ◽  
Vol 74 (8) ◽  
pp. 1524-1525 ◽  
Author(s):  
Ted Schaefer ◽  
Guy M. Bernard ◽  
Frank E. Hruska
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Dielectric Constant ◽  
Magnetic Resonance ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Coupling Constant ◽  
Spin Coupling Constant ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling ◽  
Gaseous Benzene

An excellent linear correlation (r = 0.9999) exists between the spin–spin coupling constants 1J(1H,13C), in benzene dissolved in four solvents (R. Laatikainen et al. J. Am. Chem. Soc. 117, 11006 (1995)) and Ando's solvation dielectric function, ε/(ε – 1). The solvents are cyclohexane, carbon disulfide, pyridine, and acetone. 1J(1H,13C)for gaseous benzene is predicted to be 156.99(2) Hz at 300 K. Key words: spin–spin coupling constants, 1J(1H,13C) for benzene in the vapor phase; spin–spin coupling constants, solvent dielectric constant dependence of 1J(1H,13C) in benzene; benzene, estimate of 1J(1H,13C) in the vapor; nuclear magnetic resonance, estimate of 1J(1H,13C) in gaseous benzene.

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

1969 ◽  
Vol 47 (1) ◽  
pp. 19-30 ◽  
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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