Organoruthenaborane chemistry. Part 5. Products of the reaction between closo-[B10H10]2– and [(η6-C6Me6)ClRuB3H8]. Nuclear magnetic resonance studies and the crystal and molecular structure of [{(η6-C6Me6)2Ru2H4}RuB10H8(OEt)2]

Abstract

Reaction of [{Ru(η⁶-C₆Me₆)Cl₂}₂] with Tl[B₃H₈] gives the yellow arachno four-vertex species [2-(η⁶-C₆Me₆)-2-Cl-2-RuB₃H₈](1) in a yield of 66%. Treatment of this with closo-[B₁₀H₁₀]^2– in refluxing ethanol results in the formation of yellow [1-(η⁶-C₆Me₆)-isocloso-1-RuB₉H₈-2-(OEt)](2, ca. 2% yield), yellow [1-(η⁶-C₆Me₆)-isocloso-1-RuB₁₀H₉-2-(OEt)](3, ca. 5% yield), and the novel dark red triruthenium–decaboron double-cluster compound [1-{(η⁶-C₆Me₆)₂Ru₂H₄}-isocloso-1-RuB₁₀H₈-2,3-(OEt)₂](4, 32% yield). Compounds (1)–(4) are reasonably air-stable and are characterised by n.m.r. spectroscopy. A single-crystal X-ray diffraction analysis of compound (4) showed that the crystals were monoclinic, space group P2₁/c, with a= 1 081.7(1), b= 1 622.6(3), c= 2 120.4(3) pm, β= 102.07(1)°, and Z= 4. The (η⁶-C₆Me₆)₂Ru₃H₄ sub-cluster of compound (4) exhibits novel features.