CRYSTAL-STRUCTURE AND OPTICAL-PROPERTIES OF CD32S14(SC6H5)36.DMF4, A CLUSTER WITH A 15-ANGSTROM CDS CORE

Recrystallization of the solid Cd10S4(SC6H5)12 from a solution of pyridine and N,N-dimethylformamide (DMF) results in the formation of the cluster Cd32S14(SC6H5)36.DMF4 as pale yellow cubes. The structure consists of an 82-atom CdS core that is a roughly spherical piece of the cubic sphalerite lattice approximately 12 angstroms in diameter. The four corners of the lattice are capped by hexagonal wurtzite-like CdS units, which results in an overall tetrahedral cluster approximately 15 angstroms in diameter. This cluster dissolves intact in tetrahydrofuran where its absorption spectrum reveals a sharp peak at 358 nanometers at room temperature and its emission spectra show a strong broad band at 500 nanometers.