Organoruthenaborane chemistry. Part 6. The reaction of [{Ru(η6-C6Me6)Cl2}2] with the closo-[B10H10]2– anion: characterisation of some closo-type eleven-vertex 1-ruthenaundecaboranes and the molecular structure of [5-(η-6-C6Me6)-6-(OMe)-nido-5-RuB9H12]

Abstract

The reaction between [{Ru(η⁶-C₆Me₆)Cl₂}₂] and closo-[B₁₀H₁₀]^2– in dichloromethane solution gives the eleven-vertex closo-type metallaborane [1-(η⁶-C₆Me₆)-1-RuB₁₀H₁₀](1; 82% yield) together with trace quantities of its 2-chloro derivative (2). When the reaction is carried out in refluxing methanol solution the metallaborane products are the two eleven-vertex species [1-(η⁶-C₆Me₆)-2-(OMe)-‘isocloso’-1-RuB₁₀H₉](3; 52% yield) and its 4-(OMe) isomer (4; trace quantities), together with the ten-vertex nido compound [5-(η⁶-C₆Me₆)-6-(OMe)-5-RuB₉H₁₂](5; 32% yield). The new ruthenaboranes (1)–(5) are all yellow solids, reasonably robust in air, and are characterised by n.m.r. spectroscopy, elemental analysis, and, in the case of (5), by single-crystal X-ray diffraction analysis. Crystals of (5) are monoclinic, space group P2₁/c, with a= 1 385.3(2), b= 1 030.7(2), c= 1 419.8(2) pm, β= 103.67(1)° and Z= 4.