Reinvestigation of the reaction of acid chloride with Wilkinson's catalyst: crystal and molecular structure of cis-RhCl2(PPh3)2(COC2H5) complex

• Published in: Journal of organometallic chemistry Vol. 371; no. 3; pp. 383 - 392
• Main Authors: Shie, Ju-Yeh, Lin, Ying-Chih, Wang, Yu
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.08.1989; Elsevier Science
• Subjects: Chemistry; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Organic chemistry; Organic compounds; Organometalloidal and organometallic compounds; Physics; Preparations and properties; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Transition metals derivatives; Catalytic reaction; Decarbonylation; Tertiary phosphine; Molecular structure; Organic ligand; Acyl complex; Transition metal Complexes; Experimental study; X ray diffraction; Rhodium Complexes; Chloro complex; Platinoid Complexes; NMR spectrum; Crystalline structure
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/0022-328X(89)85233-7

The interactions of Wilkinson's catalyst RhCl(PPh3)3 (1) with some acid chlorides are reported. The less known cis-complex obtained directly from oxidative addition is the subject of this study. Reaction of CH3CHClC(O)Cl with 1 initially gives the cis-Rh(III) acyl complex, RhCl2(PPh3)2(COCHClCH3) (cis-2d), which then transforms to the corresponding trans-isomer. The 13P NMR spectra of this cis-complex show the virtual coupling for the two magnetically inequivalent PPh3 ligands with the coupling constant of 15 Hz. No such virtual coupling was observed in the trans-isomer. Another five-coordinated cis-complex Cl2Rh(COC2H5)(PPh3)2 was isolated from the reaction of CH3CH2COCl with 1 at low temperature and its crystal structure has also been determined. The cis-complex crystallizes in the monoclinic space group P21/c in a cell having dimensions of a = 13.329(3), b = 14.644(3) c = 19.712(3) Å and β = 99.52(1)°. Some 2954 unique reflections with I > 2.5 σ(I) were used in the refinement to give final discrepancy indices of R = 0.045 and Rw = 0.038. The shortest RhC separation 1.95(1) Å, known for a single bond, might be the reason why the isolation and crystallization of this complex is possible.