Photochemical intermediates of trans-Rh(CO)L2Cl where L=PMe3, PBu3, and i-Pr2HN and cis-Rh(CO)2(i-Pr2HN)Cl in frozen organic glasses
摘要:
The Nujol glass matrix photolyses of Rh(CO)(PMe3)(2)Cl (1), Rh(CO)(PBu3)(2)Cl (2), Rh(CO)(2)(i-Pr2HN)Cl (3), and Rh(CO)(i-Pr2HN)(2)Cl (4), have been examined. Phototolysis of 1 (lambda(irr) > 400 nm) and 2 (350 < lambda(irr) < 400 nm) give new species, A, with carbonyl stretching bands slightly below the parent bands. In the case of 1 this species appears to give rise to a second product, C, upon either extended photolysis or annealing, High-energy photolysis of 1, 2, and 4, result in loss of CO and formation of an IR silent species. RhL2Cl. In the case of 1 a new carbonyl species, B. is observed upon high-energy photolysis or annealing of a matrix containing CO and Rh(PMe3)(2)Cl. B may be converted to 1 by either back photolysis or annealing. Compound 3 undergoes photochemical CO-loss to form two isomeric photoproducts. Comparison of the carbonyl stretching frequencies of phosphine and ammine derivatives and photoproducts made it possible to eliminate PR, loss as the source of A. DFT calculations suggest that A may be a non-planar, triplet excited state of 1 or 2. DFT calculations also support the assignment of B to cis-Rh(CO)(PMe3)(2)Cl. (C) 2002 Elsevier Science B.V. All rights reserved.
trans-[RhX(CO) L2] complexes (X = anionic ligand, L = tertiaryphosphine) from [Rh4(CO)12], phosphine (L), and acid (HX) is described. A plausible formation pathway is proposed. The electron density on the phosphorus atom in trans-[RhX(CO)L2] decreases and the length of the Rh–P bond increases with an increase in the electronegativity of the anionic ligand, X, in a cis position to the phosphine ligand. The rhodium
In the hydrogenation of olefins in alcoholic solventscatalysed by phosphinerhodium complexes a hydrogentransfer reaction from the alcohols to the olefins takes place alongside the main reaction. With primary alcohols the aldehydes formed are decarbonylated and the in situ catalysts formed from [Rh(diene)Cl]2 and phosphines are partially converted into Rh(CO)(PR3)2Cl type complexes and thereby deactivated
X-Ray photoelectron spectroscopic and infrared studies of some rhodium(I) aminophosphine complexes. Correlation with selected properties in homogeneous hydroformylation of 1-hexene
作者:J. Grimblot、J.P. Bonnelle、A. Mortreux、F. Petit
DOI:10.1016/s0020-1693(00)94673-5
日期:1979.1
Complexes of long alkyl chain tertiary phosphines. 4. Oxidative addition of methyl iodide to trans-[RhCl(CO)(PR3)2]