Structural Variation in [PdX₂{RE(CH₂)<i>_n</i>NMe₂}] (E = Se, Te; X = Cl, OAc) Complexes: Experimental Results, Computational Analysis, and Catalytic Activity in Suzuki Coupling Reactions

Abstract

Abstract A series of chalcogenoether ligands RE(CH 2 ) n NMe 2 ( 1 ) [E = Se or Te; R = Ph, o ‐tol ( o ‐tol = ortho ‐tolyl), Mes (Mes = 2,4,6‐trimethylphenyl); n = 2 or 3] and their palladium complexes [PdX 2 {RE(CH 2 ) n NMe 2 }] m [X = Cl ( 2 ) or OAc ( 3 ); m = 1, 2] were synthesized. Complexes [PdCl 2 (RECH 2 CH 2 NMe 2 )] [R/E = Ph/Se ( 2a ), Mes/Se ( 2b ), Mes/Te ( 2c )] were isolated as monomers. Complexes [PdCl 2 (RECH 2 CH 2 CH 2 NMe 2 )] m [R/E = Ph/Se ( 2d ), Ph/Te ( 2e ), o ‐tol/Te ( 2f )] exist in one monomeric and two dimeric forms in solution; their ratio depends on E and R as revealed by NMR spectroscopic data. Crystal structures of monomeric 2a , 2b , 3b , 2d , 2f , and dimeric 2e were established. Compounds 2a , 2d , 2e , and 2f were also investigated by means of density functional theory (DFT)‐based quantum chemical calculations to understand structural variation. The complexes that contained acetate or chalcogenoether ligands with n = 3 showed higher catalytic activity than other derivatives in Suzuki C–C cross‐coupling reactions.