Synthesis, characterization and structural investigation of new rhenium-oxo complexes containing bidentate phosphine ligands: an exploration of chirality and conformation in chelate rings of small and large bite angle ligands

2005 ◽  
Vol 29 (4) ◽  
pp. 613 ◽  
Author(s):  
Maria L. Parr ◽  
Carmen Perez-Acosta ◽  
J. W. Faller
Keyword(s):  
Structural Investigation ◽  
Phosphine Ligands ◽  
Oxo Complexes ◽  
Bite Angle ◽  
Bidentate Phosphine ◽  
Rhenium Oxo Complexes ◽  
Chelate Rings

Mono- and Bidentate Phosphine Ligands in the Palladium-Catalyzed Methyl Acrylate Dimerization

2003 ◽  
Vol 345 (3) ◽  
pp. 402-409 ◽  
Author(s):  
Jörg Zimmermann ◽  
Igor Tkatchenko ◽  
Peter Wasserscheid
Keyword(s):  
Methyl Acrylate ◽  
Phosphine Ligands ◽  
Palladium Catalyzed ◽  
Bidentate Phosphine

scholarly journals Quantum Mechanistic Studies of the Oxidation of Ethylene by Rhenium Oxo Complexes

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Emmanuel Adu Fosu ◽  
Collins Obuah ◽  
Louis Hamenu ◽  
Albert Aniagyei ◽  
Michael Kojo Ainooson ◽  
...  
Keyword(s):  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Frontier Molecular Orbital ◽  
Molecular Orbital Calculations ◽  
Oxo Complexes ◽  
Reaction Energies ◽  
Energy Surfaces ◽  
Rhenium Oxo Complexes ◽  
Epoxidation Catalyst ◽  
Addition Pathway

Transition-metal-mediated oxygen transfer reactions are of importance in both industry and academia; thus, a series of rhenium oxo complexes of the type ReO3L (L = O−, Cl−, F−, OH−, Br−, I−) and their effects as oxidation catalysts on ethylene have been studied. The activation and reaction energies for the addition pathways involving multiple spin states (singlet and triplet) have been computed. In all cases, structures on the singlet potential energy surfaces showed higher stability compared to their counterparts on the triplet potential energy surfaces (PESs). Frontier Molecular Orbital calculations show electrons flow from the HOMO of ethylene to the LUMO of rhenium for all complexes studied except ReO4− where the reverse case occurs. In the reaction between ReO3L (L = O−, Cl−, F−, OH−, Br−, and I−) and ethylene, the concerted [3 + 2] addition pathway on the singlet PES leading to the formation of dioxylate intermediate is favored over the [2 + 2] addition pathway leading to the formation of a metallaoxetane intermediate and subsequent rearrangement to the dioxylate. The activation and the reaction energies for the formation of the dioxylate on the singlet PES for the ligands studied followed the order O− > OH− > I− > F− > Br− > Cl− and O− > OH− > F− > I− > Br− > Cl−, respectively. Furthermore, the activation and the reaction energies for the formation of the metallaoxetane intermediate increase in the order O− > OH− > I− > Br− > Cl− > F− and O− > Br− > I− > Cl− > OH− > F−, respectively. The subsequent rearrangement of the metallaoxetane intermediate to the dioxylate is only feasible in the case of ReO4−. Of all the complexes studied, the best dioxylating catalyst is ReO3Cl (singlet surface) and the best epoxidation catalyst is ReO3F (singlet surface).

Coordination chemistry of bidentate phosphine ligands with hydrogen-bonding arms: Picket-fence rhodium complexes

Polyhedron ◽  
2014 ◽  
Vol 69 ◽  
pp. 156-159 ◽  
Author(s):  
Ilknur Babahan ◽  
James T. Engle ◽  
Nishant Kumar ◽  
Christopher J. Ziegler ◽  
Li Jia
Keyword(s):  
Hydrogen Bonding ◽  
Coordination Chemistry ◽  
Phosphine Ligands ◽  
Rhodium Complexes ◽  
Picket Fence ◽  
Bidentate Phosphine
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