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 B 3 H 7 ], 1 (Cp* = η 5 -C 5 Me 5 ) 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 B 2 H 6 S 2 ], 2 . On the other hand, the reaction of nido - 1 with diorganyldichalcogenide ligands, [Ph 2 E 2 ] afforded chalcogen bridged half sandwich complexes [(2,3-Cp*Ru) 2 B 3 H 6 (μ-η 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, 1 H, 11 B and 13 C spectroscopy. Further, the geometry of compounds 2 , 3 , 4b and 4c were unequivocally established by crystallographic analysis. [ABSTRACT FROM AUTHOR]