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Recently we described the synthesis and structural characterization of various dimetallaherteroborane clusters, namely nido-[(CpMo)BEClH], 1- 3; ( 1: E = S, x = 0; 2: E = Se, x = 0; 3: E = Te, x = 1). A combined theoretical and experimental study was also performed, which demonstrated that the clusters 1- 3 with their open face are excellent precursors for cluster growth reaction. In this investigation process on the reactivity of dimetallaheteroboranes with metal carbonyls, in addition to [(CpMo)BHEFe(CO)] ( 4: E = S, 6: E = Te) reported earlier, reaction of 2 with [ Fe(CO)] yielded mixed-metallaselenaborane [(CpMo)BHSeFe(CO)], 5 in good yield. The quantum chemical calculation using DFT method has been carried out to probe the bonding, NMR chemical shifts and electronic properties of dimolybdaheteroborane clusters 4- 6. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

In an attempt to synthesize expanded-cage metallaheteroboranes containing heavier chalcogen atoms, the reaction of diruthenaborane analogue of pentaborane(9), nido -[1,2-(Cp*RuH) 2 B 3 H 7 ] ( 1 ) with phenyl-chalcogenoborates Li[BH 3 (EPh)] (E = S, Se or Te) was carried out. Thermolysis of nido - 1 with Li[BH 3 (SPh)] led to the formation of the dimetalla-pentaborane(11) analogue arachno -[(Cp*Ru) 2 B 3 H 8 (SPh)] ( 2 ). In parallel to the formation of 2 , the reaction also yielded three B-H functionalized compounds, namely [(Cp*Ru) 2 B 4 H 7 (Ph)] ( 3 ), [(Cp*Ru) 2 B 4 H 7 (Cl)] ( 4 ) and [(Cp*Ru) 2 B 4 H 6 (SPh)(Cl)] ( 5 ). On the other hand, reaction of 1 with Li[BH 3 (SePh)] led to the formation of the diruthenium analogue of hexaborane(10) nido -[(Cp*Ru) 2 B 4 H 9 (SePh)] ( 6 ), whereas Li[BH 3 (TePh)] yielded the capped nido -pentagonal-pyramidal [(Cp*Ru) 2 B 4 H 6 Te] ( 7 ). Compound 7 is a rare ruthenaborane cluster containing a heavier chalcogen element (Te). All the compounds were characterized by mass spectrometry and 1 H, 1 H{ 11 B}, 11 B{ 1 H} and 13 C{ 1 H}NMR spectroscopy. The solid state X-ray structures of all the compounds were unequivocally established by crystallographic analysis. Additionally, the electronic properties of compound 2 were analyzed. [ABSTRACT FROM AUTHOR]