92270-18-3Relevant academic research and scientific papers
Neutral and cationic alkyne-bridged complexes of iridium and the structure of [Ir2Cl2(CO)2(μ-CH3O 2CC2CO2CH3)(Ph2PCH 2PPh2)2]·2CH2Cl2
Sutherland, Bruce R.,Cowie, Martin
, p. 1869 - 1878 (2008/10/08)
The reactions of trans-[IrCl(CO)(DPM)]2 with dimethyl acetylenedicarboxylate (DMA), hexafluro-2-butyne (HFB), and acetylene yield the species [Ir2Cl2(CO)2(μ-RC2R)(DPM) 2] (R = CO2CH3, CF3, H) in which the alkyne ligand bridges the two iridium centers as a cis-dimetalated olefin. In contrast, no reaction is observed with 2-butyne. Refluxing the DMA and HFB adducts in toluene results in CO loss to produce [Ir2Cl2(CO)(μ-RC2R)(DPM)2] (R = CO2CH3, CF3). The reaction of [Ir2Cl2(CO)2(μ-RC2R)(DPM) 2] (R = CO2CH3, CF3) with AgBF4 produces the cationic compounds [Ir2Cl(CO)2(μ-RC2R)(DPM) 2][BF4] that are observed to be fluxional on the NMR time scale. Isomers of these latter two compounds can be prepared by the reaction of DMA and HFB with [Ir2(CO)2(μ-Cl)(DPM)2][BF4]. Both sets of isomers react with CO to give [Ir2Cl(CO)3(μ-RC2R)(DPM) 2][BF4]. Refluxing these tricarbonyl species regenerates the isomers obtained by the AgBF4 route. [Ir2Cl2(CO)2(μ-DMA)(DPM) 2]·2CH2Cl2 crystallizes in the space group P1 with a = 11.880 (2) A?, b = 23.514 (3) A?, c = 11.689 (1) A?, α = 95.429 (9)°, β = 110.389 (9)°, γ = 77.999 (10)°, and Z = 2. The structure was refined to R = 0.037 and Rw = 0.067 based on 7796 unique observed reflections and 367 variables.
