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Updated: Mar 28, 2026

Synthesis of a Water-soluble Metal–Organic Complex Array
Published on: October 8, 2016
The synthesis and unexpected solution chemistry of thermochromic carborane-containing osmium half-sandwich complexes
Anaïs Pitto-Barry1, Amy South, Alison Rodger
1Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK. N.Barry@warwick.ac.uk.
Abstract:
The functionalisation of the 16-electron complex [Os(η(6)-p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-dithiolato)] (1) with a series of Lewis bases to give the 18-electron complexes of general formula [Os(η(6)-p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-dithiolato)(L)] (L = pyridine (2), 4-dimethylaminopyridine (3), 4-cyanopyridine (4), 4-methoxypyridine (5), pyrazine (6), pyridazine (7), 4,4'-bipyridine (8) and triphenylphosphine (9)) is reported. All 18-electron complexes are in equilibrium in solution with the 16-electron precursor, and thermochromic properties are observed in some cases (2, 3, 5, 8, and 9). The binding constants and Gibbs free energies of the equilibria are determined using UV-visible titrations and their stabilities investigated. Synthetic routes for forcing the formation of the 18-electron species are proposed, and analytical methods to characterise the equilibria are described.
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