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Cleavage of CO by Mo[N(R)Ar] 3 Complexes
Author(s) -
Christian Gemma,
Stranger Robert,
Yates Brian F.,
Cummins Christopher C.
Publication year - 2007
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200700304
Subject(s) - chemistry , endothermic process , dimer , cleavage (geology) , exothermic reaction , bond cleavage , crystallography , binding energy , stereochemistry , medicinal chemistry , catalysis , adsorption , organic chemistry , physics , geotechnical engineering , fracture (geology) , nuclear physics , engineering
The reaction of MoL 3 [L = NH 2 and N( t Bu)Ar] with CO was explored using DFT in order to rationalize why CO cleavage is not observed experimentally for this system in contrast to the corresponding N 2 reaction which results in spontaneous cleavage of the N–N bond. The binding of CO to MoL 3 was found to be both kinetically and thermodynamically favored over the binding of N 2 , with the formation of the encounter complex, L 3 Mo–CO, calculated to be without barrier and exothermic. While the overall reaction to form the C–MoL 3 and O–MoL 3 products was calculated to be energetically favorable, both the encounter complex and intermediate dimer, L 3 Mo–CO–MoL 3 , were found to be lower in energy than the products, with the final C–O cleavage step calculated to be endothermic by 169 kJ mol –1 and 163 kJ mol –1 for L = NH 2 and N( t Bu)Ar, respectively. The unfavorable CO cleavage step can be attributed to the fact that Mo does not possess the optimum d‐electron configuration to sufficiently stabilise the carbide and oxide products relative to the CO‐bridged intermediate dimer.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)