Book Description

The chemistry carried out with AFOSR support was aimed at exploring new materials with potentially interesting nonlinear optical properties. All of our work involved transition metal complexes. In these materials we can alter either the the metal ion or the ligands independently. In this way it is possible to alter the electronic properties of a given complex without altering its molecular or solid-state structure. Second and third order NLO properties were investigated in these materials. Both molecular and bulk nonlinearities were examined as second order candidates, while only molecular nonlinearities were examined for the third order materials. Second order properties in coordination compounds were found to scale Sc approx. Cr approx.> 5 Fe> Co- Polar coordination polymers were prepared in which excellent polar order was found in the polyermic chains, however, the adjacent chains pack antiparallel in the crystal leading to no bulk second order activity. Group 4 organometallic complexes were examined for their third order properties. Here the order based on metal was found to be Ti> Zr> Hf. The nonlinearity is thought to arise from extended molecular orbitals.