Coordination and cluster compounds of ruthenium with the [hypho-1,2-S2B6H9]− ligand

Abstract

The reaction between [tmndH][hypho-1,2-S₂B₆H₉] (tmnd = N,N,N′,N′-tetramethylnaphthalene-1,8-diamine) and [RuCl(PPh₃)₂(η⁵-Cp)] in CH₂Cl₂ at room temperature afforded two ruthenathiaboranes, [5-(η⁵-Cp)-5-(PPh₃)-5,4,6-RuS₂B₆H₉], 1, and [Ru(η¹-1,2-S₂B₆H₉)(PPh₃)₂(η⁵-Cp)], 2, in 6 and 48% yields, respectively. The heating of a solution of [Ru(η¹-1,2-S₂B₆H₉)(PPh₃)₂(η⁵-Cp)] 2 in CH₂Cl₂ at reflux temperature afforded 1 in 59% yield. Compound 1 could be described as either a hypho nine-vertex {RuS₂B₆} cluster or a coordination compound of ruthenium which contains a bidentate η²-dithiaborate cluster ligand; the latter description is preferred. Compound 2 contains an eight-atom hypho-type {1,2-S₂B₆} cage bonded to the ruthenium atom of the {Ru(PPh₃)₂(η⁵-Cp)} unit by one sulfur atom and may be described as a compound of ruthenium coordinated η¹- to the dithiaborate cluster ligand. The reaction between [tmndH][hypho-1,2-S₂B₆H₉] and [RuCl₂(η⁶-MeC₆H₄Prⁱ)]₂ in CH₂Cl₂ at room temperature afforded [5-(η⁶-MeC₆H₄Prⁱ)-arachno-5,4,6-RuS₂B₆H₈], 3, in 94% yield. Further reaction of 3 and PMePh₂ afforded another arachno {RhS₂B₆}cluster, [5-(η⁶-MeC₆H₄Prⁱ)-8-(PMePh₂)-arachno-5,4,6-RuS₂B₆H₆], 4, in 25% yield. Compounds 1, 2 and 4 were characterised with single crystal X-ray analyses.