1,4-Dicyanobutene Bridged Binuclear Iridium (￥°, ￥2) Complexes and Their Catalytic Activities

摘要

Reactions of Ir(CIO4)(CO)(PPh3)2 with dicyano olefins, cis-NCCH = CHCH2CH2CN (cDC1B), trans-NCCH = CHCH2CH2CN (tDC1B), trans-NCCH2CH = CHCH2CN (tDC2B), and NCCH2CH2CH2CH2CN (DCB) produce binuclear dicationic iridium (グ) complexes, [(CO)(PPh3)2Ir-NC-A-CN-Ir(PPh3)2(CO)](ClO4)2 (NC-A-CN = cDC1B (1a), tDC1B (1b), tDC2B (1c), DCB (1d)). Complexes 1a-1d react with hydrogen to give binuclear dicationic tetrahydrido iridium (ゲ ) complexes, [(CO)(PPh3)2(H)2Ir-NC-A-CN-Ir(H)2(PPh3)2(CO)]( ClO4)2 (NC-A-CN = cDC1B (2a), tDC1B (2b), tDC2B (2c), DCB (2d)). Complexes 2a and 2b catalyze the hydrogenation of cDC1B and tDC1B, respectively to give DCB, while the complex 2c is catalytically active for the isomerization of tDC2B to give cDC1B and tDC1B and the hydrogenation of tDC2B to give DCB at 100∩.