Crystal Structure and Optical Properties of Cd 32 S 14 (SC 6 H 5 ) 36 . DMF 4 , a Cluster with a 15 Angstrom CdS Core

Recrystallization of the solid Cd 10 S 4 (SC 6 H 5 ) 12 from a solution of pyridine and N , N -dimethylformamide (DMF) results in the formation of the cluster Cd 32 S 14 (SC 6 H 5 ) 36 ⋅DMF 4 as pale yellow cubes. The structure consists of an 82-atom CdS core that is a roughly spherical piece of the cubic sphalerite lattice ∼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 ∼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.