Theoretical Studies of the Quadratic Polarizabilities of Rigid-Rod Monomers

ABSTRACTOne of the requirements in the theoretical determination of optical nonlinearities is the structure of the molecule. Since most of the molecules that we are interested in examining have not been made, we deemed it necessary to determine their molecular geometries. The structures of 2,6-diphenylbenzo[1,2-d:4,5-d']bisoxazole, 2,6-diphenylbenzo[ 1,2-d:5,4-d']bisoxazole, and 2,2'-p-phenylenebisbenzoxazole, and their corresponding donor- and acceptor-substituted derivatives were determined computationally using the AM1 (Austin Model 1) molecular orbital program. The quadratic polarizabilities (β's) of these model compounds were then computed using the CNDO/S (Complete Neglect of Differential Overlap/ Spectroscopy) program and frontier molecular orbital theory. Results from these calculations will be expounded.