Influence of Benzannulation on Metal Coordination Geometries: Synthesis and Structural Characterization of Tris(2-mercapto-1-methylbenzimidazolyl)hydroborato Cadmium Bromide, {[Tm(MeBenz)]Cd(?-Br)}2.

ABSTRACT: The tris(2-mercapto-1-methylbenzimidazolyl)hydroborato cadmium complex, {[Tm(MeBenz)]Cd(?-Br)}2, may be synthesized via the reaction of [Tm(MeBenz)]K with CdBr2. X-ray diffraction demonstrates that {[Tm(MeBenz)]Cd(?-Br)}2 exists as a dimer, which is in marked contrast to the monomeric structure of the non-benzannulated counterpart, [Tm(Me)]CdBr, and thereby demonstrates that benzannulation of tris(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, {[Tm(MeBenz)]Cd(?-X)}2 (X = Cl, Br, I), are more stable with respect to dissociation than are their non-benzannulated counterparts, {[Tm(Me)]Cd(?-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.

SUBMITTER: Palmer JH 

PROVIDER: S-EPMC4296741 | biostudies-other | 2015 Feb

REPOSITORIES: biostudies-other