Synthesis of Chalcogenidoimidodiphosphinato–RhI Complexes and DFT Investigation of Their Catalytic Activation in Olefin Hydroformylation. Issue 7 (19th December 2012)

• Record Type: Journal Article
• Authors: Grigoropoulos, Alexios; Maganas, Dimitrios; Symeonidis, Dimitrios; Giastas, Petros; Cowley, Andrew R.; Kyritsis, Panayotis; Pneumatikakis, Georgios
• Is Part Of: European journal of inorganic chemistry. Issue 7(2013)
• Page Start: 1170
• Page End: 1183
• Publication Date: 2012-12-19
• Subjects: Rhodium -- Hydroformylation -- Density functional calculations -- Hemilabile ligands; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201200921
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: The synthesis and spectroscopic characterization of [Rh{R2 P(S)NP(S)R2 ‐ S, S′ }(cod)] [cod = 1, 5‐cyclooctadiene; R = Ph (1 ), i Pr (4 )], [Rh{Ph2 P(S)NP(S)Ph2 ‐ S, S′ }(CO)2 ] (2 ) and [Rh{Ph2 P(S)NP(S)Ph2 ‐ S, S′ }(CO)(PPh3 )] (3 ) is described. The crystal structures of complexes1 and3 are also presented. The synthesized Rh I complexes are essentially not catalytically active against olefin hydroformylation, in contrast to the previously reported complex [Rh{Ph2 P(O)NPPh2 ‐ P, O }(CO)(PPh3 )] (6 ). Differences in the catalytic activity were interpreted with the aid of a well‐defined DFT‐based protocol involving relativistic effects and dispersion correction. The steric and electronic effects of the Rh I coordination environment with respect to their activation by H2 are discussed. The results demonstrate that the presence of the more electronegative oxygen atom in the Rh I coordination sphere polarizes the H–H bond and promotes its heterolytic cleavage, thereby leading to the formation of a Rh I –monohydride complex in which the oxygen atom of the ligand is protonated. Abstract : The different catalytic properties of mono‐ and dichalcogenidoimidodiphosphinato–Rh I complexes have been investigated through a combined experimental and computational approach. The results indicate that catalytic activation proceeds by means of the ligand‐assisted heterolytic cleavage of H2 .