C L Khetrapal
Articles written in Proceedings – Section A
Volume 54 Issue 6 December 1961 pp 331-340
This paper presents the analysis of the proton magnetic resonance spectra of 2:4 dinitro phenol, 1-chloro 2:4 dinitro benzene, 1-nitro, 2-methyl, 3-chloro benzene (2-chloro, 6-nitro toluene) and 5-sulpho, 3-nitro benzoic acid based on the exact solution obtained by Jha for the splitting of NMR lines of a three nuclei system of the ABC type.
Volume 56 Issue 2 August 1962 pp 71-85
The high resolution proton magnetic resonance spectra of AB, ABC and ABCD systems in fourteen coumarins have been studied. Chemical shifts and spin coupling constants for the protons in various positions in the benzo-
The results do not substantiate resonance of the naphthalene type in coumarin as suggested to explain its dipole moment.
Volume 61 Issue 2 February 1965 pp 80-91
The NMR spectrum of five non-equivalent nuclei each with spin 1/2 in
Volume 62 Issue 2 August 1965 pp 90-96
Proton magnetic resonance studies of the solutions of (
Volume 63 Issue 1 January 1966 pp 9-19
The NMR spectra of
Volume 64 Issue 2 August 1966 pp 91-96
C13-F19 coupling constants have been measured in
The coupling constant in trifluoroacetic acid has also been measured in various solvents at several concentrations. A remarkable solvent effect on these couplings has been discovered; this appears-to be related to the dipole moment of the solvent.
Volume 64 Issue 5 November 1966 pp 315-320
A correlation between the dilution shifts of aromatic protons in non-polar, isotropic solvents and the aromaticity of the ring has been established. The aromaticities of thiophene, furan and pyridine have been estimated and the values thus obtained are compared with those obtained from other methods. The merits and the limitations of the method have been pointed out.
Volume 65 Issue 3 March 1967 pp 195-202
The effects of various polar and non-polar solvents on the proton chemical shifts in thiophene and its derivatives have been investigated. Results have been interpreted in terms of possible solute-solute, solute-solvent and solvent-solvent interactions in these systems.
Volume 65 Issue 3 March 1967 pp 203-209
The aromaticities of monosubstituted benzenes and thiophenes have been estimated using a method based on dilution shifts proposed earlier. As a result of such studies, a novel method for the study of molecular association in aromatic compounds has been proposed and utilised to study association in phenol and aniline.
Volume 65 Issue 5 May 1967 pp 265-269
Hydrogen bonding in
Volume 65 Issue 6 June 1967 pp 353-360
The relation between proton chemical shifts and pi-electron densities in aromatic systems suggested by Schug and Dech has been modified so as to include contributions due to steric effects. The proton chemical shifts in
Volume 66 Issue 4 October 1967 pp 189-195
The H-bonding of CH3OH, C6H5SH and CHCl3 with N:N Dimethyl formamide and N:N Dimethyl acetamide has been studied using proton magnetic resonance. It has been observed that the strength of interaction is greater for dimethyl acetamide than for dimethyl formamide for the same solvent. For the same solute, however, the strength increases in the order chloroform, thiol and alcohol. The equilibrium constant for 1:1 complex of these solutes in the chloroform solvent has been estimated. In the case of benzene thiol, complex formation between the pi-electrons of the phenyl ring and the amides has been detected. It has also been observed that the exchange rate of OH proton of CH3OH in the dimethyl formamide decreases considerably.
Volume 66 Issue 4 October 1967 pp 196-200
Interactions of 1, 1, 1 trifluoroacetone with proton donor solvents of the type RH [where R=HO, CH3S, CH3CH2CH2CH2S, CH3O, (CH3)2N, (C2H5)2N] have been investigated using NMR and infra-red techniques. Evidence of the formation of addition products of the type CF3.C(OH)R.CH3 where OH group is hydrogen-bonded with the fluorine of the CF3 group has been obtained.
Volume 67 Issue 6 June 1968 pp 322-327
Interactions of compounds containing OH group with acrylonitrile, 2 : 3 dichloropropene, allyl cyanide and allyl halides have been studied using NMR and IR techniques. Hydrogen bonds of the type O-H ··· N have been detected. With allyl halides bonds of the type O-H ··· Cl have been detected for allyl chloride only. The value of the equilibrium constant has been calculated for O-H ··· N bonds using IR studies.