Sulfur and oxygen functionalized cyclopentadienyl half-sandwich cobalt complexes with 1,2-dicarba- closo-dodecaborane-1,2-dichalcogenolato ligands

Abstract

Sulfur and oxygen functionalized cyclopentandienyl half-sandwich cobalt dicarbonyl complexes [η 5-C 5H 4(CH 2) 2SCH 2CH 3]Co(CO) 2 ( 3) and [η 5-C 5H 4(CH 2) 2OCH 3]Co(CO) 2 ( 7) were prepared. Oxidation of 3 or 7 with I 2 led to formation of 18-electron complexes [η 5-C 5H 4(CH 2) 2SCH 2CH 3]CoI 2 ( 4) and [η 5-C 5H 4(CH 2) 2OCH 3]Co(CO)I 2 ( 8). The reactions of diiodide complex ( 4) with dilithium 1,2-dicarba- closo-dodecaborane(12)-1,2-dichalcogenolates [(THF) 3LiE 2C 2B 10H 10Li(THF)] 2 [E=S ( 1a), Se ( 1b)] afforded 18-electron mononuclear complexes [η 5-C 5H 4(CH 2) 2SCH 2CH 3]Co(E 2C 2B 10H 10) [E=S ( 5a), Se ( 5b)] in which sulfur atoms of side-chain were attached via an intramolecular coordination. Complex 7 reacted with 1a and 1b to give the binuclear complexes {[η 5-C 5H 4(CH 2) 2OCH 3]Co(E 2C 2B 10H 10)} 2 [E=S ( 10a), Se ( 10b)]. The molecular structures of 5a and 10b were determined by X-ray crystallographic analysis. According to the X-ray structure analyses, 10b contains two o-carborane diselenolate bridges, and each Cp ′Co fragment is attached to one terminal and two bridging selenolato ligands. The central Co 2Se 2 four-membered ring is planar, and the direct metal–metal interaction is absent.