Formation of anionic carbonylrhodium complexes from Wilkinson's complex under conditions of hydroformylation of formaldehyde

Abstract

The compositions and the dynamics of transformations of carbonylrhodium complexes formed from Wilkinson's complex, RhCl(PPh3)3, dissolved in mesitylene—N,N-dimethylacetamide (DMAA) mixtures in which the DMAA concentration varied from 0 to 100 %, in an atmosphere of synthesis gas\(p_{{\text{CO + H}}_{\text{2}} } \) = 6 MPa,T=373 K) were investigatedin situ by IR spectroscopy. The anion complexes, [Rh(CO)2(PPh3) x (DMAA) y ]− (x=1, 2;y=1, 0) and [Rh(CO)4]−, which are the centers of formaldehyde hydroformylation, are produced in noticeable quantities when 100 % DMAA is used as a solvent. Separate steps of the formation of anionic complexes from RhCl(PPh3)3 have been identified. Under the conditions of hydroformylation of formaldehyde, CH2O participates in the formation of the anionic complexes, along with DMAA.