<title>Nonlinear optical properties of lithium-containing derivatives</title>

Abstract

The polarizability and first and second hyperpolarizabilities of several 4,4'-disubstituted trans- stilbene (tSB) derivatives, which include the NO<SUB>2</SUB> group as an acceptor (A) and several lithium containing donors (D) have been computed. Ab initio theory using a 6-31G basis set at the SCF and MP2 levels has been sued to optimize the structure of tSB and the disubstituted derivative which includes the NO<SUB>2</SUB> (A) and the NLi<SUB>2</SUB> (D). Their polarizabilities and hyperpolarizabilities have also been computed at the SCF level. MP2 theory has been used to assess the effect of correlation on the largest polarizability and second hyperpolarizability components of the above compounds. The preset results, together with our recent work show that the second hyperpolarizabilities of some lithiated derivatives depend quite a lot on the molecular geometries and lithiation leads to a big increase of the hyperpolarizabilities of the resulting derivatives. This finding suggests that at lest some of the lithiated derivatives are very likely to be useful for non-linear optical applications.