Synthesis and crystal structures of [W(3,6-dichloro-1,2-benzenedithiolate)3]n=1, 2) and [Mo(3,6-dichloro-1,2-benzenedithiolate)3]2- :: Dependence of the coordination geometry on the oxidation number and counter-cation in trigonal-prismatic and octahedral structures

The novel complexes (Et4N)(2)[W(bdtCl(2))(3)] (1a), (Ph4P)(2)-[W(bdtCl(2))(3)] (1b), (Et4N)[W(bdtCl(2))(3)] (2a), (Ph4P)[W(bdtCl(2))(3)] (2b), (C5NH6)[W(bdtCl(2))(3)] (2c), and (Et3NH)(2)]MO(bdtCl(2))(3)] (3a) (bdtCl(2) 3,6-dichloro-1,2-benzenedithiolate) were prepared and characterized by X-ray crystallographic, UV/Vis spectroscopic, and electrochemical methods. Versatile geometrical changes around the tungsten centers were observed. The trigonal-prismatic structure of the tungsten center in (Et4N)2[W(bdtCl2)31 (1a) is changed to an intermediate structure between trigonal prismatic and octahedral upon solid-state oxidation of the complex to (Et4N)[W(bdtCl(2))(3)] (2a). Replacement of the counter-cation of (Et4N)(2)[W(bdtCl(2))(3)] (1a) with Ph4P+ also resulted in geometrical changes and somewhat of an octahedral contribution is included in (Ph(4)p)(2)-[W(bdtCl(2))(3)] (1b). However, almost the same coordination structures are present in the series of structures (Et4N)[W(bdtCl(2))(3)] (2a), (Ph4P)[W(bdtCl(2))(3)] (2b), and (C5NH6)[W(bdtCl(2))(3)] (2c), with an oxidation number of +5. These structures adopt an intermediate geometry between trigonal prismatic and octahedral. No geometrical change was observed upon changing the metal center from tungsten to molybdenum in [M(bdtCl(2))(3)](2-) (M = W and Mo). (c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.