Molecular Modeling of Photoluminescent Copper(i) Cyanide Materials

Studies show that solid copper(I) cyanide has interesting photoluminescent properties. Recent work has shown that the UV spectrum of CuCN may be attributed to Laporte-allowed excitations from occupied to unoccupied π-type molecular orbitals (MOs). The emission spectrum is attributed to the relaxation from an excited state triplet with a bent structure due to distortions that remove degeneracies in the partially occupied MOs of the linear triplet. The addition of aliphatic and aromatic amines to CuCN chains leads to substantial changes in the structural and photophysical properties of the material including shifts in λmax for both the excitation and emission spectra and orbital mixing. The study of CuCN materials has been expanded to examine the affect of amines on substituted CuCN (zigzag and helical) chains that were optimized at the DFT (BLYP) level. Timedependent DFT (TD-DFT) studies on the optimized structures of these model compounds reveal that the excitations for the substituted chains are generally consistent with the unsubstituted chains; however, differences are attributed to type of ligand, structure, and stoichiometry.