Tennyson, A. G.; Dhar, S.; Lippard, S. J. Synthesis and Characterization of {Ni(NO)}10 and {Co(NO)2}10 Complexes Supported by Thiolate Ligands.
Journal of the American Chemical Society 2008,
130, 15087-15098.
Abstract
Nitric oxide is an important mol. in biol. and modulates a variety of physiol. and pathophysiol. processes. Some of its regulatory functions are exerted through interactions with redox-active elements, including Fe, Ni, Co, and S. Metalloenzymes contg. [nFe-nS] (n = 2 or 4) clusters can be activated or inactivated by reaction with NO, affording dinitrosyl Fe complexes. Studies of the NO chem. of small-mol. Fe thiolate complexes provided insight into these biol. processes and suggested probable intermediates. To explore this chem. from a different perspective, the authors prepd. Ni and Co thiolate complexes and studied their reactions with NO and related compds. The authors report here the first examples of anionic complexes contg. {Ni(NO)}10 and {Co(NO)2}10 units, the reactivity of which suggests possible intermediates in the interconversion of Fe thiolate nitrosyl compds. The authors' results demonstrate new chem. involving NO and simple complexes of Ni and Co supported by thiolates, which were known for >30 years. The use of mass balance methodol. was key to their discovery. Among the novel complexes reported are (Et4N)2[Ni(NO)(SPh)3] (2), from (Et4N)2[Ni(SPh)4] (1) and NO, (Et4N)2[Ni2(NO)2(μ-SPh)2(SPh)2] (3), from 1 and NO+ or 2 and Me3O+, (Et4N)[Co(NO)2(SPh)2] (5), from (Et4N)2[Co(SPh)4] (4) and NO, and [Co3(NO)6(μ-SPh)3] (6), from 5 and Me3O+. In the syntheses of 2 and 5, NO could be replaced by the convenient solid Ph3CSNO. [on SciFinder(R)]