TDDFT study on electronic excitations and first hyperpolarizabilities of mixed-metal carbonyl clusters MonIr4-n(mu-CO)(3)(beta(5)-Cp)(n) (n=1,2,3)

摘要

A series of mixed-metal carbonyl clusters, MonIr4-n(mu-CO)(3)(eta(5)-Cp)(n) (n= 1, 2; Cp=C5H4Me, C5HMe4, C5Me5, C5H5), have been investigated using the TDDFT method. The results estimated the medium magnitude of the first static hyperpolarizabilities (beta(tot) similar to 2 x 10(-30)esu) of these tetrahedral mixed-metal clusters, most of which originate from the intra-cluster charge transfer of the metal skeleton consisting of polar metal-metal interactions. No direct contributions of the Cp ligands to the relevant charge transfer were found, but the cooperative effect between the metal centres and Cp ligands impacts the beta. Based on these studies a mixed-metal cluster Mo3Ir(mu-CO)(3)(CO)(7)(eta(5)-Cp)(2) was designed that exhibits enhanced first hyperpolarizability.