TDDFT Study on the Electronic Excitations and First Hyperpolarizabilities of Mixed-metal Carbonyl Clusters W2Ir2（μ-L）（CO）8（η^5-C5H4Me）2（L = dppe/dppf）

Mixed-metal carbonyl clusters of W2Ir2（CO）10（η^5-C5H4Me）2 1 and W2Ir2（μ-L）（CO）8（η^5-C5H4Me）2 （L = dppe 2, dppf 3） have been studied by TDDFT method focusing on their electronic and nonlinear optical properties. These three clusters exhibit the first static hyperpolarizabilities of medium magnitude （βtot-10×10^-30 esu）. The origin of β is discussed by the new proposed orbital-pair decomposition scheme by Barandes et al. The result suggests that the β values of the two clusters are mainly originated from d-d electron transition within the metal skeleton, and d-p （π＊） electron transition from metals to carbonyls and phenyl. The additional coordination by the electron donor group, ferrocene, makes cluster 3 own much larger β values, and the relatively longer range charge transfer from d orbitals of ferrocene to d orbirals of Ir and W is responsible for the enhanced β values.

TDDFT Study on the Electronic Excitations and First Hyperpolarizabilities of Mixed-metal Carbonyl Clusters W2Ir2(μ-L)(CO)8(η5-C5H4Me)2(L=dppe/dppf)

Mixed-metal carbonyl clusters of W2Ir2(CO)10(η5-C5H4Me)2 1 and W2Ir2(μ-L)(CO)8(η5-C5H4Me)2(L=dppe 2,dppf 3)have been studied by TDDFT method focusing on their electronicand nonlinear optical properties.These three clusters exhibit the first static hyperpolarizabilities ofmedium magnitude (βtot~10×10-30 esu).The origin of βis discussed by the new proposed orbital-pairdecomposition scheme by Barandes et al.The result suggests that the β values of the two clusters aremainly originated from d-d electron transition within the metal skeleton,and d-p(π*)electrontransition from metals to carbonyls and phenyl.The additional coordination by the electron donorgroup,ferrocene,makes cluster 3 own much largerβvalues,and the relatively longer range chargetransfer from d orbitals of ferrocene to d orhirals of Ir and W is responsible for the enhanced βvalues.