Effects of p-substituents on the conformation of acetophenone

1981 ◽  
Vol 34 (7) ◽  
pp. 1443 ◽  
Author(s):  
D Mirarchi ◽  
GLD Ritchie

Experimental dipole moments and infinite-dilution molar Kerr constants are reported for six p-substituted acetophenones (CH3COC6H4X; X = Me, But, NO2, CN, F, Br) as solutes in carbon tetrachloride at 298 K. Analysis of these results and reconsideration of previously reported data for acetophenone and p-chloroacetophenone yields the dihedral angle, Φ, between the planes of the carbonyl and aryl groups in the effective conformation of each molecule (X = H, Φ = 0°; Me, 0°; But, 10�10°; NO2, 20�15°; NO2, 20�20°; F, 27�5°; Cl, 32�5°; Br, 30�10°).

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.


1982 ◽  
Vol 35 (11) ◽  
pp. 2341 ◽  
Author(s):  
D Mirarchi ◽  
GLD Ritchie

Infinite-dilution dipole moments (1030p/Cm) and molar Kerr constants (1027mK/m5 V-2 mol-1) for 1-pivaloylnaphthalene (8.83,-490) and 2-pivaloylnaphthalene (9.24, 218) as solutes in carbon tetrachloride at 25�C are reported and analysed to yield the dihedral angles between the Car-CO-C and naphthyl planes as 90 � 10� and 53 � 8�, respectively.


1957 ◽  
Vol 10 (3) ◽  
pp. 218 ◽  
Author(s):  
CG Le Fevre ◽  
RJW Le Fevre ◽  
WT Oh

Values for the properties and compounds named in the title are recorded at infinite dilution in carbon tetrachloride at 25 �C. Dipole moments of the seven diesters lie between 2 2 and 2.8 D ; the molar Kerr constants of the two azodiformates however differ from those of the maleates, fumarates, and oxalate in being negative. Results with ethyl oxalate are consistent with a structure in which the two ?CO2Et groups are in planes making an azimuthal angle c. 90�. Indications of configurations for the other esters are discussed, but conclusions are indefinite.


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.


1967 ◽  
Vol 45 (10) ◽  
pp. 1097-1100 ◽  
Author(s):  
E. Bock ◽  
E. F. Dojack

The dipole moments of the ethylene derivatives acrylonitrile, chloroacrylonitrile, methyl vinyl ketone, vinyl bromide, 1,1-dichloroethylene, and tribromoethylene were determined in benzene solution at 20 °C. The measured dipole moments were corrected for the solvent effect by the method of Looyenga. In addition the applicability of the Looyenga equation for the solvent effect was tested on earlier reported data for 20 different molecules, whose dipole moments were derived from dilute benzene and carbon tetrachloride solutions, respectively. The corrected dipole moment values were compared with earlier corrected values calculated according to the method of Le Fevre and Le Fevre and with reported gas values. It was found that for most compounds both methods of correction yielded dipole moment values which differed by 0–10% from the gas values.


1982 ◽  
Vol 35 (3) ◽  
pp. 663
Author(s):  
D Mirarchi ◽  
GLD Ritchie ◽  
AJ Williams

Analysis of the experimental infinite-dilution molar Kerr constants of five p-substituted benzaldehydes (X-C6H4-CHO; X = NO2, CN, F, Cl, Br) as solutes in carbon tetrachloride at 298 K confirms that uniplanar molecular conformations are preferred.


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.


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