om050897e_si_002.cif (190.12 kB)
Synthesis of a Library of Iridium-Containing Dinuclear Complexes with Bridging PNNN and PNNP Ligands (BL), [LM(μ-BL)M‘L‘]BF4. 2. Preparation, Basic Coordination Properties, and Reactivity of the Carbonyl Complexes
dataset
posted on 2006-03-13, 00:00 authored by Christian Dubs, Toshiki Yamamoto, Akiko Inagaki, Munetaka AkitaA series of dinuclear carbonyl complexes with PNNP and PNNN ligands, [(L)M(PNNX)M‘(L)]BF4
(X = P, N; M(L), M‘(L‘) = Ir(CO)2, Rh(CO)2, Pd(allyl)), have been prepared by carbonylation (1 atm)
of the corresponding cod complexes, and the Rh/Ir complexes have been further converted to μ-η1:η2-acetylide complexes, where effective π-back-donation to the acetylide ligand is essential to stabilize
them. On the basis of the stability of the acetylide complexes, the π-donating ability of the metal fragment
in the PNNX system is estimated to be (P,N)Rh > (P,N)Ir > (N,N)M. The dinuclear PNNX complexes
catalyze alkyne hydrogenation, alkene hydroformylation, and allylation of aniline with allyl alcohol, and,
for the allylation, a dinuclear mechanism involving activation of allyl alcohol by interaction with a CO
ligand is proposed.