TY - JOUR
T1 - Mechanisms for CO production from CO 2 using reduced rhenium tricarbonyl catalysts
AU - Agarwal, Jay
AU - Fujita, Etsuko
AU - Schaefer, Henry F.
AU - Muckerman, James T.
PY - 2012/3/21
Y1 - 2012/3/21
N2 - The chemical conversion of CO 2 has been studied by numerous experimental groups. Particularly the use of rhenium tricarbonyl-based molecular catalysts has attracted interest owing to their ability to absorb light, store redox equivalents, and convert CO 2 into higher-energy products. The mechanism by which these catalysts mediate reduction, particularly to CO and HCOO -, is poorly understood, and studies aimed at elucidating the reaction pathway have likely been hindered by the large number of species present in solution. Herein the mechanism for carbon monoxide production using rhenium tricarbonyl catalysts has been investigated using density functional theory. The investigation presented proceeds from the experimental work of Meyer's group (J. Chem. Soc., Chem. Commun.1985, 1414-1416) in DMSO and Fujita's group (J. Am. Chem. Soc.2003, 125, 11976-11987) in dry DMF. The latter work with a simplified reaction mixture, one that removes the photo-induced reduction step with a sacrificial donor, is used for validation of the proposed mechanism, which involves formation of a rhenium carboxylate dimer, [Re(dmb)(CO) 3] 2(OCO), where dmb = 4,4′-dimethyl-2, 2′-bipyridine. CO 2 insertion into this species, and subsequent rearrangement, is proposed to yield CO and the carbonate-bridged [Re(dmb)(CO) 3] 2(OCO 2). Structures and energies for the proposed reaction path are presented and compared to previously published experimental observations.
AB - The chemical conversion of CO 2 has been studied by numerous experimental groups. Particularly the use of rhenium tricarbonyl-based molecular catalysts has attracted interest owing to their ability to absorb light, store redox equivalents, and convert CO 2 into higher-energy products. The mechanism by which these catalysts mediate reduction, particularly to CO and HCOO -, is poorly understood, and studies aimed at elucidating the reaction pathway have likely been hindered by the large number of species present in solution. Herein the mechanism for carbon monoxide production using rhenium tricarbonyl catalysts has been investigated using density functional theory. The investigation presented proceeds from the experimental work of Meyer's group (J. Chem. Soc., Chem. Commun.1985, 1414-1416) in DMSO and Fujita's group (J. Am. Chem. Soc.2003, 125, 11976-11987) in dry DMF. The latter work with a simplified reaction mixture, one that removes the photo-induced reduction step with a sacrificial donor, is used for validation of the proposed mechanism, which involves formation of a rhenium carboxylate dimer, [Re(dmb)(CO) 3] 2(OCO), where dmb = 4,4′-dimethyl-2, 2′-bipyridine. CO 2 insertion into this species, and subsequent rearrangement, is proposed to yield CO and the carbonate-bridged [Re(dmb)(CO) 3] 2(OCO 2). Structures and energies for the proposed reaction path are presented and compared to previously published experimental observations.
UR - http://www.scopus.com/inward/record.url?scp=84858674455&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84858674455&partnerID=8YFLogxK
U2 - 10.1021/ja2105834
DO - 10.1021/ja2105834
M3 - Article
C2 - 22364649
AN - SCOPUS:84858674455
VL - 134
SP - 5180
EP - 5186
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 11
ER -