Structures and Nonlinear Optical Properties of the Alkalides M+aza222M′- (M, M′=Li, Na, K)

Using density functional theory with the B3LYP functional, the optimized structures of the organic alkalides M(+)aza222M'(-) (M, M'=Li, Na, K, and aza222=Azacryptand[2.2.2]) were calculated. The nonlinear optical (NLO) properties of these species were calculated by the BHandHLYP method. The results indicate that the M(+)aza222M'(-) alkalides exhibit very large first hyperpolarizabilities (beta(0),) up to 1.0x10(6) a.u. (for M=Li, M'=K). Both the first hyperpolarizabilities and the M-M' distances of M(+)aza222M'(-) were found to depend on the atomic number of the alkali metal atom M(M'). By comparing the beta(0) values of various organic alkalides, aza222 was found to be preferable to the previously investigated complexants in enhancing the first hyperpolarizabilities of alkalides.