Homocubane Chemistry: Synthesis and Structures of Mono- and Dicobaltaheteroborane Analogues of Tris- and Tetrahomocubanes
Résumé
Room-temperature reactions between [Cp*CoCl] (Cp* = η-CMe) and large excess of [BHE]Li (E = S or Se) led to the formation of homocubane derivatives, . These species are bimetallic tetrahomocubane, [(Cp*Co)(μ-S)(μ-S)BH], ; bimetallic trishomocubane isomers, [(Cp*Co)(μ-S)(μ-S)BH], and ; monometallic trishomocubanes, [M(μ-E)(μ-E)BH] [: M = Cp*Co, E = S; : M = Cp*Co, E = Se and : M = {(Cp*Co)(μ-H)(μ-Se)}Co, E = Se], and bimetallic homocubane, [(Cp*Co)(μ-Se)(μ-Se)BH], . As per our knowledge, is the first isolated and structurally characterized parent prototype of the 1,2,2',4 isomer of tetrahomocubane, while , , and are the analogues of parent -trishomocubane. Compounds and are the structural isomers in which the positions of the μ-S ligands in the trishomocubane framework are altered. Compound is an example of a unique vertex-fused trishomocubane derivative, in which the -trishomocubane [Co(μ-Se)(μ-Se)BH] moiety is fused with an exopolyhedral trigonal bipyramid (tbp) moiety [(Cp*Co)(μ-H)(μ-Se)}Co]. Multinuclear NMR and infrared spectroscopy, mass spectrometry, and single crystal X-ray diffraction analyses were employed to characterize all the compounds in solution. Bonding in these homocubane analogues has been elucidated computationally by density functional theory methods.
Domaines
Chimie de coordination
Origine : Publication financée par une institution
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