STRUCTURE AND NONLINEAR-OPTICAL PROPERTIES OF THE CUBIC CAGE COMPLEX (N-BU(4)N)(3)[CU3MOOS3BRI3]

Unlike the analogous (n-Bu(4)N)(3)[Cu3MoOS3Br4], in which the cluster has a partially open cage structure, in the salt (n-Bu(4)N)(3)[CU3MoOS 3BrI3] the anion for ms a cubane-like cluster, consisting of a (Cu3Mo) tetrahedron interlocked with an (S3I) tetrahedron. The solid crystall izes in the cubic space group F<(4)over bar 3c> (a = 24.422(3) Angstro m;Z = 8), the cluster adopting 12 allowed orientations randomly. This material exhibits a strong nonlinear optical absorption and a large, s elf-defocusing refractive index change. This behavior is intermediate between that of analogous nest-shaped clusters with an Mo=O group and cubic cage clusters with an Mo=S group, indicating that both the natur e of the metal-chalcogenide and the overall skeletal structure of the cluster influence the nonlinear optical properties of the material.