A "Double-Diamond Superlattice" Built Up of Cd 17 S 4 (SCH 2 CH 2 OH) 26 Clusters

Abstract

A simple preparation of Cd₁₇S₄(SCH₂CH₂OH)₂₆ clusters in aqueous solution leads to the formation of colorless blocky crystals. X-ray structure determinations revealed a superlattice framework built up of covalently linked clusters. This superlattice is best described as two enlarged and interlaced diamond or zinc blende lattices. Because both the superlattice and the clusters display the same structural features, the crystal structure resembles the self-similarities known from fractal geometry. The optical spectrum of the cluster solution displays a sharp transition around 290 nanometers with a large absorption coefficient (∼84,000 per molar per centimeter).