Monodentate palladium(0)–[60]fullerene complexes of diphosphine ligands as efficient and sustainable nanocatalysts for the Mizoroki–Heck coupling reaction of aryl chlorides

Two mononuclear coordination complexes of fullerene[60] with Pd(dba)(2) (dba = dibenzylideneacetone), [(eta(2)-C-60) Pd(Ph2P(CH2)(2)PPh2=C(H) C(O) R)(2)] (R = C10H7 (1), C6H4Cl (2)), have been prepared using a simple procedure to explore new directions in palladium catalysis and nanocarbon chemistry. The palladium(0)-[60] fullerene complexes incorporating unsymmetrical phosphorus ylides have been characterized by H-1, C-13 and P-31 NMR spectroscopic methods and other conventional techniques such as IR, TGA, SEM, ICP-OES, EDX and TEM analysis. Attributed to the enhanced dispersity and uniform size of the Pd nanoparticles with phosphine-functionalized fullerenes, the prepared catalysts exhibited comparable catalytic activity to those reported for the Mizoroki-Heck coupling reaction of aryl chlorides. Because of their abundance and low cost, aryl chlorides are the most desirable substrates from an industrial point of view in Csp(2)-Csp(2) coupling reactions. Furthermore, overall bonding modes in the palladafullerenes of bifunctional diphosphine-based ligands were investigated by spectroscopic analysis and theoretical calculations. DFT studies of geometry-optimized monodentate and bidentate structures for 1 were calculated at the B3LYP/LANL2MB level of theory to understand the origin of the observed coordination modes.