106520-04-1Relevant articles and documents
Transition-metal derivatives of the cyclopentadienyl phosphine ligands. 3. New pathways to polymetallic complexes
He, Xiao Dong,Maisonnat, André,Dahan, Fran?oise,Poilblanc, René
, p. 2618 - 2626 (2008/10/08)
A series of new derivatives of heterodifunctional ligands have been synthesized starting from lithium (diphenylphosphino)- or ((diphenylphosphino)ethyl)cyclopentadienide and from ((diphenylphosphino)-cyclopentadienyl)- or ((dimethylphosphino)cyclopentadienyl)thallium. These are monometallic (1,2, and 4) and heterobimetallic molybdenum(0), tungsten(0), iridium(I), and iridium(I) complexes (3) together with dissymmetric (5) and symmetric (6) homobimetallic rhodium(I) and iridium(I) complexes. They have been fully characterized by their spectroscopic data (including phosphorus-rhodium and phosphorus-tungsten coupling constant measurements) and by electron-impact mass spectroscopy. Interestingly, the synthesis of the bimetallic compounds involves a novel pathway beginning with steps of coordination of the phosphorus extremity of the bifunctional ligands. Of special interest are the compounds L2Rh(η5-C5H4)Ph 2PRhCl(PPh3)L (5), which associate one 18-electron and one 16-electron site, and the compounds [M(η5-C5H4)PR2(CO)]2 (M = Rh, Ir; R = Ph, Me) (6), which associate two 18-electron sites. Complex 6a (M = Rh; R = Ph) crystallizes in the triclinic space group P1 with one molecule in the unit cell of dimensions a = 9.475 (1) A?, b = 9.527 (1) A?, c = 9.145 (1) A?, α = 99.80 (1) A?, β = 109.86 (1)°, γ = 90.36 (1)°, and V = 763.2 (3) A?3. Least-squares refinement leads to a value of 0.032 for the conventional R index for 2938 reflections having I > 3σ(I). The dinuclear molecule consists of two "Rh(CO)" moieties bridged by two (diphenylphosphino) cyclopentadienyl ligands that are in a mutual head-to-tail arrangement, and the large Rh-Rh separation, 4.3029 (6) A?, precludes any metal-metal interaction.