Solvents, effect on conformation

Yun-Yu S, W Lu and W F van Gunsteren 1988. On the Approximation of Solvent Effects on Conformation and Dynamics of Cyclosporin A by Stochastic Dynamics Simulation Teclmiqi Molecular Simulation 1 369-383. 

Foresman et al.175 applied the DFT(B3LYP)/SCRF calculations to obtain the polar solvent effect on conformational equilibria in furfuraldehyde and on the C-C rotational barrier of (2-nitrovinyl)amine. The authors demonstrated that the poor results obtained using either spherical or ellipsoidal cavities can be significantly improved upon performing the SCRF calculations for the cavity of molecular shape. 

The above examples show that comparison of gas and solution phase rate constants reveals the direction and magnitude of solvent effects on conformational processes. At present it is not possible to attribute the observed solvent effects to specific causes for several reasons. Qualitative trends can be determined, but the lack of detailed studies in the liquid phase limits a quantitative analysis. 

Professor Lemieux recalls the following incident from this period. In connection with studies then being performed on solvent effects on conformational equilibria, Dr. Mills suggested that 1,2-O-isopropyli-dene 4-0-methyl-/3-L-sorbopyranose should be examined. The ex-... 

Zalesny, R., Bartkowiak, W., Styrcz, S., Leszczynski, J. Solvent effects on conformationally induced enhancement of the two-photon absorption cross section of a pyridinium-A -phenolate betaine dye. A quantum-chemical study. J. Phys, Chem. A 106, 4032-4037 (2002)... 

Solvent Effects on Conformational Change of Chemical Compounds... 

THEORETICAL EVALUATION OF SOLVENT EFFECT ON CONFORMATIONAL EQUILIBRIA OF SUGARS... 

Figure 6,58 Solvent effects on conformational equilibrium in 2-methoxytetrahydropyran.

Use of the combined QM/MM model for studying conformational equilibria has been described by Warshel, Jorgensen, 8o and by Field, Bash, and Karplus.35 The first computer simulation of the solvent effects on conformational equilibrium with a combined QM/MM approach, however, was carried out in 1992 in the investigation of the relative basicity of the syn and anti lone pairs of acetate ion in water. 81 In recognizing that the basicity difference... 

Solvent effects on conformational equilibria can be pronounced, with higher populations of more polar isomers in polar solvents. This is reflected in Bell s expression for the free energy of solvation of a dipole fx with radius / in a continuum with dielectric constant e. ... 

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