Mixed-metal cluster chemistry III .PC activation at tungsten-triiridium cores; X-ray crystal structures of [CpwIr3{μ3-η2-PPh(C6H4})(μ-CO)2(CO)7] and [CpWIr3{μ3-η2-PPh(C6H4)}(μ-CO)2(CO)6(PPh3)]
摘要:
The thermolysis of [CpWIr(3)(mu-CO)(3)(CO)(7)(PPh(3))] in refluxing toluene gives [CpWIr(3){mu-eta(2)-PPh(C6H4)}(mu-CO)(2)(CO)(7)] (1) in good yield (56%), together with [CpWIr(3)(CO)(11)] (2) (32%); an analogous reaction with [CpWIr(3)(mu-CO)(3)(CO)(6)(PPh(3))(2)] gives 1 (23%) and [CpWIr(3){mu(3)-eta(2)-PPh(C6H4)}(mu-CO)(2)(CO)(6)(PPh(3))] (3) (39%). Products 1 and 3 (in 15 and 44% yield respectively) are also obtained from heating [CpWIr(3)(mu-CO)(3)(CO)(5)(PPh(3))(3)]. Both 1 and 3 have been structurally characterized, The structural studies show that orthometallation has occurred, to afford products with (phenylphosphido)phenyl-P,C ligands capping the triiridium faces, In 3, the intact PPh, resides at an iridium ligated by the phosphorus of the capping group, Attempts to effect further P-C cleavage of 1 (pyrolysis, photolysis, reaction with trimethylamine-N-oxide) were unsuccessful, as were attempts to effect C-H activation at the analogous[CpWIr(3)(mu-CO)(3)(CO)(7)(PMe(3))].