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Four homodinuclear rare earth metal (RE) complexes 1-4 bearing a multidentate diglycolamine-bridged bis(phenolate) ligand were synthesized. In addition, seven heterobimetallic RE-Zn complexes 5-11 were prepared through a one-pot strategy. In these heterobimetallic complexes, two RE centers are bridged by either Zn(OAc)2 or Zn(OBn)2 moieties. All complexes were characterized by single crystal X-ray diffraction, elemental analysis, IR spectroscopy, and multinuclear NMR spectroscopy (in the case of diamagnetic complexes 1, 4, 7 and 11). Moreover, the multi-nuclear structures of complexes 4 and 11 in solution were also studied by 1H DOSY spectroscopy. These complexes were applied in catalyzing the coupling reaction of carbon dioxide (CO2) with epoxides. Zn(OAc)2- and Zn(OBn)2-bridged heterobimetallic complexes showed comparable catalytic activities under ambient conditions and were more active than monometallic RE complexes. Significant synergistic effect in heterobimetallic complexes is observed. Mono-substituted epoxides were converted into cyclic carbonates under 1 atm CO2 at 25 °C in 88-96% yields, whereas di-substituted epoxides reacted under 1 atm CO2 at higher temperatures in 40-80% yields.

Four homodinuclear rare earth metal (RE) complexes 1-4 bearing a multidentate diglycolamine-bridged bis(phenolate) ligand were synthesized. In addition, seven heterobimetallic RE-Zn complexes 5-11 were prepared through a one-pot strategy. In these heterobimetallic complexes, two RE centers are bridged by either Zn(OAc)

Mono- and dinuclear group 3 metal complexes incorporating polydentate bis(imino)phenoxy {N

International audience; Three heterometallic rare earth metal-zinc complexes were synthesized and structurally characterized. They catalyzed the cycloaddition of CO2 with epoxides at ambient temperature and pressure, which generated a wide range of cyclic carbonates in good yield (44-98%). This is the first rare earth metal-based homogenous catalysts, which are active and recyclable under ambient conditions. The synergistic effect of the two metal centers is evidenced by means of computational study.

Zirconium complexes supported by multidentate aminophenolato ligands were synthesized and characterized. The catalytic activities of neutral zirconium complexes and their cationic derivatives in the hydrophosphination of alkenes as well as heterocumulenes have been investigated and compared. Neutral complex 1 bearing a multidentate amino mono(phenolato) ligand exhibited high activity in hydrophosphination of simple alkenes, and anti-Markovnikov products were obtained in 37-94% yields at room temperature. Cationic species generated in situ from complex 3 stabilized by a bis(phenolato) ligand were found to be more active for hydrophosphination of heterocumulenes, i.e., carbodiimides and isocyanates, and gave phosphaguanidines and phosphaureas in 67-93% yields. The Lewis acidity and coordination space of metal centers are modified through changes in the ligand structure, which is found to significantly influence catalytic activity. These complexes are among the most active group 4 metal-based catalysts for hydrophosphination reactions.