Synthesis and molecular structures of di- and trinuclear molybdenum complexes containing pyridine-2-thiolato (pyS) ligand

Abstract

Dinuclear complexes [Mo 2(μ-pyS) 2(CO) 4(PPh 3) 2], [Mo 2(μ-pyS) 2(CO) 5(PPh 3)] ( 2) and a trace quality of trinuclear complex [Mo 3( μ-pyS) 3( μ 3-pyS) 2(CO) 6] ( 3) were obtained from the reaction of [Mo(CO) 3(MeCN) 3] with pyridine-2-thione (pySH) and PPh 3 in THF. The crystal structures of 1 · 2C 7H 8 and 3 · C 7H 8 have been determined by X-ray diffraction studies. Crystals of 1 · 2C 7H 8 are monoclinic, space group C2 c and Z = 4, with a = 18.797(3), b = 11.143(4), c = 28.157(7) A ̊ , β = 101.23(2)° . The structure was refined to R = 0.050 and Rw = 0.057 for 3146 observed reflections. Crystals of 3 · C 7H 8 are monoclinic, space group P2 a and Z = 4, with a = 13.912(2), b = 17.161(2), c = 15.577(3) A ̊ , β = 101.17(1)° . The structure was refined to R = 0.046 and Rw = 0.051 for 4357 observed reflections. The molecule of 1 consists of two Mo(CO) 2(PPh 3) fragments linked by an MoMo (2.974(2) Å0 and by two doubly-bridging pyS ligands. The compound 3 contains a bent open geometry of three molybdenum atoms (Mo(1)Mo(2)Mo(3) angle 122.99(3)°) linked by two MoMo bonds (2.943(1) and 2.950(1) Å) and by two doubly- and two triply-bridging pyS ligands.