Rational construction of oligomeric polymetallic ensembles consisting of Ru_2H_4 subunits interconnected by flexible carbon chains

摘要

Novel dinuclear ruthenium bromo-carbonyl complexes {(-~5-C _5Me_4)(CH_2)_n(-~5-C _5Me_4)}Ru_2(CO)_4Br_2 (n = 4 (4a), 5 (4b), and 6 (4c)) are synthesized by the metalation of the corresponding bis(cyclopentadiene)-type ligands C_5Me_4H(CH _2)_nC_5Me_4H (n = 4, 5, and 6) with Ru_3(CO)_(12), followed by bromination. Allylation of 4 with allyl bromide and subsequent treatment with LiEt_3BH affords tetranuclear ruthenium octahydride complexes 6a-c, composed of two Ru _2H_4 sites. X-ray diffraction analysis reveals that the approximate geometry of the four ruthenium atoms in 6b is parallelogram shaped.