Pc. Ray et al., A COMPARATIVE-STUDY OF FIRST HYPERPOLARIZABILITIES OF THE ACIDIC AND BASIC FORMS OF WEAK ORGANIC-ACIDS IN WATER, The Journal of chemical physics, 105(21), 1996, pp. 9633-9639
Dynamic and static first hyperpolarizabilities (beta) of a series of b
enzoic and cinnamic acids in water have been investigated. These acids
exist in a mixture of acidic and basic forms in solution. The hyperpo
larizability of the basic form is higher than that of the correspondin
g acid form which is attributed to the red-shift of the absorption max
imum of the basic form relative to that of the acid form. A ZINDO-corr
ection vector (CV) method including solvent effects through a self-con
sistent reaction held (SCRF) for computing beta reproduce measured val
ues within experimental errors. Static oh initio hyperpolarizabilities
within SCRF are slightly lower than the ZINDO/CV/SCRF beta's Semiempe
rical as well as ab initio gas phase calculations show the correct exp
erimental trend in beta but their magnitudes are much smaller than the
measured values. (C) 1996 American Institute of Physics.