Diruthenium analogues of Hexaborane(12) and Pentaborane(9): Synthesis and structural characterization of [(1,2-Cp*Ru)2B2H6S2] and [(2,3-Cp*Ru)2B3H6(μ-η1-EPh)], (E = S, Se and Te) (Cp* = η5-C5Me5)

In an objective to synthesize metallaheteroboranes containing heavier chalcogen atoms, we performed the reaction of dimetallaborane analogues of pentaborane(9) with various chalcogen sources. As a result, the thermolysis of nido-[1,2-(Cp*RuH)(2)B3H7], 1 (Cp* = eta(5)-C5Me5) with mixture of S and Se powder was carried out, that led to the isolation of half sandwich dimetallaheteroborane arachno-[(1,2-Cp*Ru)(2)B2H6S2], 2. On the other hand, the reaction of nido-1 with diorganyldichalcogenide ligands, Ph2E2] afforded chalcogen bridged half sandwich complexes [(2,3-Cp*Ru)(2)B3H6(mu-eta(1)-EPh)], 4a-c (4a: E = S; 4b: E = Se and 4c: E = Te). Compound 2 can be derived from a closo-snub disphenoid by removing a 5-connect vertex followed by the removal of a 3-connect vertex. Compound 4a-c can be described as nido-square pyramidal structures, isoelectronic and isostructural with nido-1. All the compounds have been characterized by mass spectrometry, H-1, B-11 and C-13 spectroscopy. Further, the geometry of compounds 2, 3, 4b and 4c were unequivocally established by crystallographic analysis. (C) 2014 Elsevier B.V. All rights reserved.