Dipole moments, Kerr constants and other properties of acetoacetic ester and acetylacetone

1977 ◽  
Vol 30 (3) ◽  
pp. 503
Author(s):  
MA Cusiter ◽  
Fevre RJW Le ◽  
D Millar ◽  
RK Pierens

The proportions of the keto and en01 isomers of ethyl acetoacetateand of acetylacetone incyclohexane, carbon tetrachloride and benzene have been determined by n.m.r. spectroscopy, and expressed as functions of the solute concentrations. Routine methods sufficed for all other observations, except those of electric birefringence, which needed to be examined by a pulsed-voltage technique. The dipole moments and molar Kerr constants so obtained are analysed to provide corresponding data for the separate tautomers. Possible conformations of these keto and en01 molecules can be inferred from considerations involving known bond polarities and anisotropic polarizabilities.

1980 ◽  
Vol 33 (12) ◽  
pp. 2597 ◽  
Author(s):  
PH Gore ◽  
IG John ◽  
RK Pierens ◽  
GLD Ritchie

Experimental dipole moments and molar Kerr constants are reported and analysed for di(pyridin-4-yl), di(pyridin-3-yl) and di(pyridin-2-yl) ketone as solutes in carbon tetrachloride or cyclohexane at 298 K. The preferred conformation of di(pyridin-4-yl) ketone is found to be very similar to those previously deduced for benzophenone and several 4,4'- disubstituted benzophenones. For di(pyridin-3-yl) and di(pyridin-2-yl) ketone three analogous conrotatory structures having different relative dispositions of the nitrogen atoms are considered. In the case of di(pyridin-3-yl) ketone the cis-trans and trans-trans arrangements are approximately equally abundant, but for di(pyridin-2-yl) ketone there is a strong preference for the trans-trans conformation.


1981 ◽  
Vol 34 (2) ◽  
pp. 349 ◽  
Author(s):  
LHL Chia ◽  
KJ Kwan ◽  
HH Huang

Electric dipole moments and molar Kerr constants are reported for seven organic carbonates (dimethyl carbonate, diethyl carbonate, vinylene carbonate, diphenyl carbonate, di-p-tolyl carbonate, di-o- tolyl carbonate and t-butyl phenyl carbonate) examined as solutes in carbon tetrachloride at 25�. The experimental data are analysed to provide information on the probable solution-state conformations.


1976 ◽  
Vol 29 (3) ◽  
pp. 581 ◽  
Author(s):  
MJ Aroney ◽  
EAW Bruce ◽  
IG John ◽  
L Radom ◽  
GLD Ritchie

Ab initio molecular orbital theory has been used to deduce the preferred gas-phase conformations of vinyl formate and vinyl acetate. In addition, experimental dipole moments (1030μ/Cm) and molar Kerr constants (1027mK/m5 V-2 mol-1) at 25�C are reported for both molecules as solutes in carbon tetrachloride: vinyl formate (5.07, + 48.1) and vinyl acetate (5.70, + 3.8). The preferred solution-state conformations indicated by the analysis of these results are shown to be consistent with the theoretical predictions.


1987 ◽  
Vol 40 (3) ◽  
pp. 619 ◽  
Author(s):  
MJ Aroney ◽  
RJW LeFevre ◽  
RK Pierens ◽  
HJ Stootman ◽  
MGM Yong

Measurements are reported of the infinite-dilution dipole moments and molar Kerr constants of dimethyl sulfone and of the four aryl methyl sulfones p-XC6H4S(02)CH3 (X = H, Cl, Br or NO2) dissolved in carbon tetrachloride or dioxan at 298 K and under light of 589 nm. The experimental data are analysed to obtain information on the solution-state conformations in relation to steric and electromeric effects operative between the aryl and methanesulfonyl groups.


1980 ◽  
Vol 33 (10) ◽  
pp. 2181 ◽  
Author(s):  
PH Gore ◽  
IG John ◽  
GLD Ritchie

Experimental dipole moments and molar Kerr constants are reported for eight 4- and 4,4?-halogeno- and -methyl-benzophenones as solutes in carbon tetrachloride at 298 K. Analysis of the results elucidates the conformational preferences of these molecules and suggests that steric effects are of predominant importance, whereas the additional conjugative interactions provided by the substituents apparently play only a minor role.


1973 ◽  
Vol 26 (8) ◽  
pp. 1785 ◽  
Author(s):  
CL Cheng ◽  
GLD Ritchie

Experimental dipole moments and molar Kerr constants at 25�C are reported for di(4-pyridyl) disulphide (1.68 D, + 11 x 10-12 e.s.u. mol-1) and di(2-pyridyl) disulphide (3.95 D, -240x10-12 e.s.u. mol-1) as solutes in carbon tetrachloride. Analysis of results yields information concerning the preferred conformations of these molecules.


1968 ◽  
Vol 21 (8) ◽  
pp. 1965
Author(s):  
FRJW Le ◽  
RK Pierens ◽  
DV Radford ◽  
KD Steel

The apparent dipole moments of ten, and the apparent molar Kerr constants of seven, alkyl nitrites as solutes in carbon tetrachloride at 25� are recorded and discussed in terms of assumptions that the dissolved species are either (a) mixtures of two planar forms in which the R-O and K=O bonds have an s-cis : s-trans relationship, or (b) mixtures of many non-planar rotamers, definable by angles of twist 4 between the planes containing the R-O and S=O units. On basis (b) the observed properties are average values, theoretically predictable only when potential energies as functions of � become known. "Effective" conformations for MeO-N=O and Me3CO-N=O having � values of 98� and 146.5� can be inferred from the ∞(mK2) values found for these esters.


1962 ◽  
Vol 15 (4) ◽  
pp. 703 ◽  
Author(s):  
RS Armstrong ◽  
MJ Aroney ◽  
RJW Le Fevre

Dipole moments and molar Kerr constants, previously recorded by Le F�vre, Le F�vre, and Oh (1957) with only a qualitative discussion pending availability of information on the anisotropic polarizabilities of the C=C and N=N bonds, are here used to indicate the apparent conformations of diethyl maleate, diethyl fumarate, and diethyl azodiformate as solutes in carbon tetrachloride.


1980 ◽  
Vol 33 (11) ◽  
pp. 2343 ◽  
Author(s):  
RS Armstrong ◽  
MJ Aroney ◽  
BS Higgs ◽  
KR Skamp

Electric dipole moments and molar Kerr constants are reported for Ph3SiH, Ph3SiCl, (Ph3Si)2O, Ph2SiH2, Ph2SiMe2 and Ph2SiCl2 as solutes in carbon tetrachloride or cyclohexane solution at 298 K. The data are analysed in terms of the preferred solution-state conformations.


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