A dinuclear phosphite rhodium(I) complex obtained by syngas treatment of a Rh/hydroxy phosphonite olefin hydroformylation precatalyst

Abstract

A hydroxy phosphonite was found to be unstable during the catalyst preformation routine applied towards a rhodium olefin hydroformylation catalyst. C-P bond cleavage occurred when the phosphonite was reacted with [(acac)-Rh(1,5-COD)] (acac is acetyl acetate and 1,5-COD is cycloocta-1,5-diene) at 80 C and 20 bar of CO/H 2 . As a result, a nearly planar six-membered ring structure consisting of two rhodium(I) cations and two bridging phosphorous acid diester anions was formed, namely bis [-(4,8-,3,2]dioxaphosphepin-6-yl)oxy]-1:2 2 P:O;1:2 2 O:P-bis{[6-([1,1 0 -biphenyl]-2-yloxy)-4,8-di-tert-butyl-2,10-dimethoxydibenzo[d,f][1,3,2]dioxaphosphepine-P]carbonylrhodium(I)} toluene tetrasolvate, [Rh 2 (C 22 H 28 O 5 P) 2 -(C 34 H 37 O 5 P) 2 (CO) 2 ]Á4C 7 H 8 . Further coordination of phosphite and of carbonyl groups resulted in 16-electron rhodium centres. research papers Acta Cryst. (2019). C75, 398-401 Selent et al. A dinuclear phosphite rhodium(I) complex 399 Figure 1 Products obtained from the reaction of two different rhodium sources with phosphonite I and syngas. research papers 400 Selent et al. A dinuclear phosphite rhodium(I) complex Acta Cryst. (2019). C75, 398-401 research papers Acta Cryst. (2019). C75, 398-401 Selent et al. A dinuclear phosphite rhodium(I) complex 401