Nonlinear optical properties of mixed Mo/Fe, mixed chalcogen clusters Cp2Mo2Fe2STe(CO)7and Cp2Mo2Fe2(m3-S)(m3-Te)(m2-SPh)(m3-H)(CO)5

Abstract

Studies of the third order optical nonlinearity of the mixed-metal, mixed chalcogen clusters Cp2Mo2Fe2STe(CO)7 and Cp2Mo2Fe2(μ3-S)(μ3-Te)(μ2- SPh)(μ3-H)(CO)5 using 532 nm, 6 ns laser pulses are reported. The second compound is the first example in literature of a mixed Fe/Mo mixed chalcogen complex containing a bridging thiolate group. The effective nonlinear absorption coefficient and nonlinear index intensity coefficient of these compounds are measured by the Z-scan technique, from which the corresponding cubic hyperpolarizabilities are evaluated. The obtained values indicate a high nonlinearity comparable to some of the best values reported previously for cluster compounds. Both compounds show strong optical limiting. In addition, their photostability is found to be much superior to many of the previously reported highly nonlinear clusters.