Molybdenum and tungsten complexes of the N(CH2CH2S)33− (NS3) ligand with oxide, sulfide, diazenide, hydrazide and nitrosyl co-ligands

Abstract

Reaction of [MoO₂(acac)₂] with N(CH₂CH₂SH)₃ in CH₂Cl₂ gave an insoluble, red, diamagnetic complex formulated as [{MoO(NS₃)}₂] 1 [NS₃ = N(CH₂CH₂S)₃³⁻] together with a small amount of dark red, diamagnetic [{Mo(NS₃)}₂(μ-S)] 2. The linear, sulfur-bridged structure of 2 was confirmed by a crystal structure determination. With NH₂NHR (R = Me or Ph) in CH₂Cl₂, 1 gave soluble, red, diamagnetic diazenides [Mo(NS₃)(N₂R)] (R = Me 3 or Ph 4) whereas with N₂H₄ it gave a dark brown, insoluble compound formulated as [{Mo(NS₃)(N₂H)}_n] 5. The crystal structures of 3 and 4 have been obtained. Both 3 and 4 react with mineral acids HX (X = BF₄ or Cl) in CH₂Cl₂ to give the yellow-brown, diamagnetic hydrazides [Mo(NS₃)(N₂HR)]X (6, R = Me, X = BF₄; 7, R = Me, X = Cl; 8, R = Ph, X = BF₄), which deprotonate in more basic solvents to regenerate the parent complexes. Compound 3 reacted with [Me₃O]BF₄ to give yellow, diamagnetic [Mo(NS₃)(N₂Me₂)]BF₄9 and with NO to give yellow, diamagnetic [Mo(NS₃)(NO)] 10, whose crystal structure shows it to have a linear MoNO system. Reaction of N(CH₂CH₂SH)₃ with [{Mo(μ-Br)Br(CO)₄}₂] and [WI₂(CO)₃(MeCN)₂] gave the poorly soluble, diamagnetic complexes [{M(NS₃)}₂{μ-SCH₂CH₂N(CH₂CH₂SH)₂-S}₂] (M = Mo 11 or W 12) whose structures have been established by determination of the crystal structure of 12.