Open platinum aggregate frameworks with overhead dithiolate bridges

Abstract

A convenient method has been developed to bring together two discrete moieties of [Pt2(μ-S)2(PPh3)4] to give an open Pt4 aggregate of Pt2⋯(spacer) ⋯Pt2, as exemplified in the isolation of [(PPh 3)4Pt2(μ-S)(μ-SRS)(μ-S)Pt 2(PPh3)4](PF6)2 [R = m-CH2C6H4CH2, p-CH2C 6H4CH2, CH2C10H 6CH2, and CH2(C6H4) 2CH2]. The spacer is a dithiolate with an extended skeletal backbone formed from the alkylation of sulfide with a suitable dibromo-organic compound. This synthetic methodology can tolerate a range of conformationally contrasting thiolate substituents with different chemical functionalities. Shorter or stereochemically more restrictive spacers could opt to be an intramolecular bridge over the Pt2 core, as given in [Pt2(μ-S-o-CH2C6H4-C 6H4CH2S)(PPh3)4](PF 6)2. A few representative complexes have been characterized by single-crystal X-ray diffraction analysis. © Wiley-VCH Verlag GmbH & Co. KGaA, 2007.