Rheingold Arnold L, Zakharov Lev N, Trofimenko Swiatoslaw
Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
Inorg Chem. 2003 Feb 10;42(3):827-33. doi: 10.1021/ic0205280.
New homoscorpionate ligands containing a 3-benzyl substituent, hydrotris(3-benzyl-5-methylpyrazol-1-yl)borate, Tp(Bn,Me), and hydrotris(3-benzyl-4-phenylpyrazol-1-yl)borate, Tp(Bn,4Ph), have been synthesized, and the dynamic behavior of a number of metal complexes was studied by NMR. Structures of the complexes Tl[Tp(Bn,Me)], 1, Tl[Tp(Bn,4Ph)], 2, Co[Tp(Bn,Me)][Tp(Np)], 3, MoTp(Bn,Me)(2)NO, 4, Co[Tp(Bn,4Ph)][Tp], 5, and MoTp(Bn,Me)(2)(eta(3)-methallyl), 6, were determined by X-ray crystallography. In the Tp(Bn,Me) ligand, the benzyl group is freely rotating and provides less steric hindrance to the coordinated metal than a neopentyl group, but steric hindrance is increased in the Tp(Bn,4Ph) ligand, where the rotation of the benzyl substituent is restricted by the 4-phenyl substituent.
