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NH 3 Synthesis in the N 2 /H 2 Reaction System using Cooperative Molecular Tungsten/Rhodium Catalysis in Ionic Hydrogenation: A DFT Study
Author(s) -
Moha Verena,
Leitner Walter,
Hölscher Markus
Publication year - 2016
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201504660
Subject(s) - heterolysis , pincer movement , pincer ligand , catalysis , chemistry , rhodium , hydride , tungsten , cationic polymerization , ionic bonding , density functional theory , catalytic cycle , medicinal chemistry , inorganic chemistry , computational chemistry , polymer chemistry , ion , organic chemistry , hydrogen
The ionic hydrogenation of N 2 with H 2 to give NH 3 is investigated by means of density functional theory (DFT) computations using a cooperatively acting catalyst system. In this system, N 2 binds to a neutral tungsten pincer complex of the type [(PNP)W(N 2 ) 3 ] (PNP=pincer ligand) and is reduced to NH 3 . The protons and hydride centers necessary for the reduction are delivered by heterolytic cleavage of H 2 between the N 2 –tungsten complex and the cationic rhodium complex [Cp*Rh{2‐(2‐pyridyl)phenyl}(CH 3 CN)] + . Successive transfer of protons and hydrides to the bound N 2 , as well as all N x H y units that occur during the reaction, enable the computation of closed catalytic cycles in the gas and in the solvent phase. By optimizing the pincer ligands of the tungsten complex, energy spans as low as 39.3 kcal mol −1 could be obtained, which is unprecedented in molecular catalysis for the N 2 /H 2 reaction system.