Kerr constant and dipole moment

Measurements of dipole moments, Kerr constants, and dielectric absorption have been employed (81RCR336) widely to obtain information on the conformational equilibrium in acyl heterocycles. Details on conformer structures and populations depend on the choice of additive scheme, group moments, or polarizability tensor in the case of Kerr constants. Several early conclusions, especially for furan- and thiophene-2-carboxaldehyde, appeared contradictory, owing to the choice of these quantities. A more precise definition of polarizability tensors for several heterocycles and a choice of group moments and additive schemes tested on a large amount of available experimental results and supported by accurate theoretical calculations have led to more confidence in the use of experimental dipole moments and Kerr constants in conformational analysis. A limitation of the method is that the... 

The results of dipole moment and Kerr constant elaboration indicated (84JST(116)377) that in the 2-pivaloyl derivatives of furan and pyrrole the... 

Dipole moments and Kerr constants of dibenzoates of several diols are measured at 298 K. Theoretical analysis is performed with standard methods of the RIS model. Comparison of theory with experiment indicates that is almost insensitive to the conformational energies, particularly for m > 3. Kerr constants are much more sensitive to the conformational energies. Good agreement between theoretical and experimental values of both dipole moments and Kerr constants of all these compounds is achieved by adjustement of the optical parameters and the... 

Based on dipole moments and Kerr constants, Arbusov and co-workers showed that the experimental and calculated data on 2-chloro-4-methyl-l,3,2-dioxarsinane are consistent with a chair conformation with axial chlorine and equatorial methyl <74mi 626-02,75izvi757>. 

General discussion of intra- and intermolecular interactions 3 van der Waals interactions 3 Coulombic interactions 5 Medium effects on conformational equilibria 5 Quantum mechanical interpretations of intramolecular interactions 7 Methods of study 8 Introduction 8 Nmr and esr spectroscopy 8 Microwave spectroscopy (MW) 12 Gas-phase electron diffraction (ED) 12 X-ray crystallographic methods 13 Circular-dichroism spectroscopy and optical rotation 14 Infrared and Raman spectroscopy 18 Supersonic molecular jet technique 20 Ultrasonic relaxation 22 Dipole moments and Kerr constants 22 Molecular mechanic calculations 23 Quantum mechanical calculations 25 Conformations with respect to rotation about sp —sp bonds 27 Carbon-carbon and carbon-silicon bonds 28 Carbon-nitrogen and carbon-phosphorus bonds 42 Carbon-oxygen and carbon-sulphur bonds 48 Conformations with respect to rotation about sp —sp bonds Alkenes and carbonyl derivatives 53 Aromatic and heteroaromatic compounds 60 Amides, thioamides and analogues 75 Conclusions 83 References 84... 

Dipole moment and Kerr constant data have been used in a conformational study of some epoxidized cyclohexanes, for example the di-epoxide (21) exists in a... 

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