title: Influence of Benzannulation on Metal Coordination Geometries: Synthesis and Structural Characterization ofTris(2-mercapto-1-methylbenzimidazolyl)hydroborato Cadmium Bromide, {[TmMeBenz]Cd(μ-Br)}2.
abstract: Thetris(2-mercapto-1-methylbenzimidazolyl)hydroborato cadmium complex, {[TmMeBenz]Cd(μ-Br)}2, may be synthesizedviathe reaction of [TmMeBenz]K with CdBr2. X-ray diffraction demonstrates that {[TmMeBenz]Cd(μ-Br)}2exists as a dimer, which is in marked contrast to the monomeric structure of the non-benzannulated counterpart, [TmMe]CdBr, and thereby demonstrates that benzannulation oftris(2-mercapto-1-methylbenzimidazolyl)hydroborato ligands can have a distinct impact on the molecular structure of their metal complexes. In accord with this observation, density functional theory calculations indicate that the benzannulated dimers, {[TmMeBenz]Cd(μ-X)}2(X = Cl, Br, I), are more stable with respect to dissociation than are their non-benzannulated counterparts, {[TmMe]Cd(μ-X)}2. Furthermore, the calculations also indicate that the stability of the dimer depends on the nature of X, such that the dimer becomes more stable in the sequence I < Br < Cl.
authors.affiliation: Department of Chemistry, Columbia University, New York, New York 10027, USA.
authors.forename: Joshua H
authors.initials: JH
authors.lastname: Palmer
authors.affiliation: Department of Chemistry, Columbia University, New York, New York 10027, USA.
authors.forename: Gerard
authors.initials: G
authors.lastname: Parkin
keywords: Cadmium; benzannulation; halide; trigonal-bipyramidal; tris(2-mercaptoimidazolyl)hydroborato