92345-44-3Relevant articles and documents
Synthesis of binuclear cationic complexes of iridium containing a dimetalated olefin and the crystal and molecular structures of [Ir2(CO)3Cl(μ-H3CO2CC=CCO 2CH3)((C6H5)2PCH 2P(C6H5)2)2]-PF 6·CH3CN
Mague, Joel T.,Klein, Cheryl L.,Majeste, Richard J.,Stevens, Edwin D.
, p. 1860 - 1869 (2008/10/08)
A new synthesis of [Ir2(CO)3Cl(μ-CO)(DPM)2]A (DPM = bis(diphenylphosphino)methane; A = BPh4, PF6, ClO4) is reported. These complexes react with dimethyl acetylenedicarboxylate and methyl propiolate to yield the dimetalated olefin derivatives [Ir2(CO)3Cl(μ-H3CO2CC=CCO 2CH3)(DPM)2]A and [Ir2(CO)3Cl(μ-HC=CCO2CH 3)(DPM)2]BPh4. The former (A = ClO4, PF6) loses one carbonyl group on refluxing in tetrahydrofuran. In solution these dicarbonyl complexes undergo chloride exchange between the two metal atoms and add trimethyl phosphite to give [Ir2(CO)2(P(OMe)3)(μ-H3CO 2CC=CCO2CH3)(DPM)2]ClO4. When A = BPh4, decarbonylation occurs similarly, but the product reacts with the anion to yield the phenyl derivative [Ir2(CO)2(C6H5)(μ-H 3CO2CC=CCO2CH3)(DPM) 2]BPh4 plus [Ir2(CO)2Cl2(μ-H3CO 2CC= CCO2CH3)(DPM)2]. The phenyl complex adds 1 equiv of tert-butyl isocyanide to yield [Ir2(CO)2(CNC(CH3)3)(C 6H5)(μ-H3CO2CC=CCO 2CH3)(DPM)2]BPh4 and reacts with carbon monoxide to form [Ir2(CO)3(C6H5)(μ-H 3CO2CC=CCO2CH3)(DPM) 2]BPh4. An excess of tert-butyl isocyanide converts [Ir2(CO)3Cl(μ-H3CO2CC=CCO 2CH3)(DPM)2]BPh4 to [Ir2(CNC(CH3)3)4(μ-H 3CO2CC=CCO2CH3)(DPM) 2]2+, which was isolated as the tetraphenylborate salt. [Ir2(CO)3Cl(μ-H3CO2CC=CCO 2CH3)(DPM)2]PF6·CH 3CN crystallizes in the space group P21/n with a = 10.531 (9) A?, b = 27.522 (3) A?, c = 20.233 (4) A?, β = 92.40 (4)°, V = 5859.2 A?3, and Z = 4. The structure was refined by using the 8129 independent reflections with I ≥ 3σ(I) to final residuals of R = 0.034 and Rw = 0.044. Each iridium atom in the binuclear cation can be considered to have a distorted square-pyramidal coordination with a carbonyl ligand in the apical position, a phosphorus atom of each DPM ligand in trans-basal positions, and a carbon atom of the dimetalated olefin. Completing the basal plane of Ir1 is a second carbonyl ligand while for Ir2 it is the chloride ligand. The Ir1-Ir2 distance of 2.8933 (2) A? is indicative of the presence of a metal-metal single bond.
