Reactions of [MoO2(2,3-butanediolate)2]·2(butane-2,3-diol) with Phenylhydrazine in methanol, followed by an arenethiolate ligand, yield complex binuclear anions with (organodiazenido)molybdenum centers triply bridged by thiolato groups. The synthesis of analogous rhenium species may be accomplished from appropriate precursors and the properties compared to those of the molybdenum complexes. The chemical and structural consequences of the thiolate ligand type are illustrated by the structures of [Mo2(NNHPh)(NNPh)(SCH2CH2S)3(SCH2CH2SH)]2-(22-) and [Mo2(NNPh)4(SPh)5]- (3a-), isolated as [NHEt3]+ salts. Complex 2 exhibits gross geometric features common to the triply bridged class of molybdenum-oxo and tungsten-oxo species. Each molybdenum center is coordinated to the sulfur donors of a terminal bidentate ethanedithiolate ligand, three bridging thiolate donors from a bidentate bridging dimercaptoethane group and a monodentate dithiolate, and the α-nitrogen of a linearly coordinated organodiazenido (NNR) or organohydrazido(2-) (NNHR) ligand. The short Mo-Mo distance of 2.837 Å is consistent with the metal-metal interaction invoked for this type of complex; similar structural details are observed for the structure of [HNEt3]-[Re2(NNPh)2(SPh)7] (4), synthesized from the reaction of [ReCl(NNPh)2(PPh3)2] with thiophenol. In contrast, complex 3a, while exhibiting the triply thiolate-bridged geometry, presents a Mo-Mo distance of 3.527 (1) Å and bridge symmetry consistent with the description of the structure in terms of confacial octahedra, rather than edge-sharing square pyramids with a long axially bridging interaction, the appropriate description for all other members of this class of triply bridged binuclear complexes. Crystal data: for 2, triclinic space group P1, a = 10.224 (2) Å, b = 10.874 (3) Å, c = 35.942 (8) Å, α = 86.59 (1)°, β = 88.79 (1)°, γ = 61.96 (1)°, V = 3520.5 (10) Å, Z = 3, and R = 0.052 for 5699 reflections; for 3a, triclinic space group P1, a = 10.994 (2) Å, b = 12.173 (2) Å, c = 24.179 (4) Å, α = 91.03 (1)Å, β = 91.45 (1)°, γ = 109.78 (1)°, V= 3042.9 (12) Å3, Z = 2, and R = 0.059 for 4763 reflections; for 4, monoclinic space group P21/n, a = 16.137 (2) Å, b = 9.863 (2) Å, c = 16.668 (2) Å, β = 111.12 (1)°, V = 2474.4 (7) Å3, Z = 4, and R = 0.055 for 2984 reflections.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry