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Title: Studies of the decomposition of the ethylene hydrophenylation catalyst TpRu(CO)(NCMe)Ph

Abstract

TpRu(CO)(NCMe)Ph is a catalyst for the conversion of benzene and ethylene to ethylbenzene. Previously, the formation of ethylbenzene has been shown to occur through a pathway that involves ethylene coordination to Ru, insertion of ethylene into the Ru–phenyl bond and Ru–mediated benzene C–H activation. Here, the effect of ethylene pressure and catalyst concentration (between 0.2 and 0.01 mol % based on benzene) on the decomposition of TpRu(CO)(NCMe)Ph was examined. Studies have shown that there are two competing catalyst deactivation pathways. At higher concentrations of TpRu(CO)(NCMe)Ph, the dominant deactivation pathway is likely initiated by a binuclear reaction of two Ru complexes that leads to formation of unidentified paramagnetic species. Kinetic studies show that this pathway for catalyst decomposition occurs with a second-order rate of 0.007 (1) M-1 s-1. At lower Ru concentrations, ethylene C–H activation to form the allyl complex TpRu(CO)(η3-C4H7) is the predominant deactivation pathway. The effect of ethylene pressure on catalyst decomposition was also examined. At higher ethylene pressure nearly quantitative formation of TpRu(CO)(η3-C4H7) was observed.

Authors:
 [1];  [2];  [3]; ORCiD logo [2]
  1. Univ. of Virginia, Charlottesville, VA (United States); Univ. of Sewanee, TN (United States)
  2. Univ. of Virginia, Charlottesville, VA (United States)
  3. Univ. of North Texas, Denton, TX (United States)
Publication Date:
Research Org.:
Univ. of Virginia, Charlottesville, VA (United States); Univ. of North Texas, Denton, TX (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences, and Biosciences Division
OSTI Identifier:
1596960
Grant/Contract Number:  
SC0000776; FG02-03ER15387
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Organometallic Chemistry
Additional Journal Information:
Journal Volume: 847; Journal Issue: C; Journal ID: ISSN 0022-328X
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; C–H activation; Ethylene; Hydroarylation; Ruthenium; Homogeneous catalysis

Citation Formats

Joslin, Evan E., McKeown, Bradley A., Cundari, Thomas R., and Gunnoe, T. Brent. Studies of the decomposition of the ethylene hydrophenylation catalyst TpRu(CO)(NCMe)Ph. United States: N. p., 2017. Web. doi:10.1016/j.jorganchem.2017.03.051.
Joslin, Evan E., McKeown, Bradley A., Cundari, Thomas R., & Gunnoe, T. Brent. Studies of the decomposition of the ethylene hydrophenylation catalyst TpRu(CO)(NCMe)Ph. United States. https://doi.org/10.1016/j.jorganchem.2017.03.051
Joslin, Evan E., McKeown, Bradley A., Cundari, Thomas R., and Gunnoe, T. Brent. Thu . "Studies of the decomposition of the ethylene hydrophenylation catalyst TpRu(CO)(NCMe)Ph". United States. https://doi.org/10.1016/j.jorganchem.2017.03.051. https://www.osti.gov/servlets/purl/1596960.
@article{osti_1596960,
title = {Studies of the decomposition of the ethylene hydrophenylation catalyst TpRu(CO)(NCMe)Ph},
author = {Joslin, Evan E. and McKeown, Bradley A. and Cundari, Thomas R. and Gunnoe, T. Brent},
abstractNote = {TpRu(CO)(NCMe)Ph is a catalyst for the conversion of benzene and ethylene to ethylbenzene. Previously, the formation of ethylbenzene has been shown to occur through a pathway that involves ethylene coordination to Ru, insertion of ethylene into the Ru–phenyl bond and Ru–mediated benzene C–H activation. Here, the effect of ethylene pressure and catalyst concentration (between 0.2 and 0.01 mol % based on benzene) on the decomposition of TpRu(CO)(NCMe)Ph was examined. Studies have shown that there are two competing catalyst deactivation pathways. At higher concentrations of TpRu(CO)(NCMe)Ph, the dominant deactivation pathway is likely initiated by a binuclear reaction of two Ru complexes that leads to formation of unidentified paramagnetic species. Kinetic studies show that this pathway for catalyst decomposition occurs with a second-order rate of 0.007 (1) M-1 s-1. At lower Ru concentrations, ethylene C–H activation to form the allyl complex TpRu(CO)(η3-C4H7) is the predominant deactivation pathway. The effect of ethylene pressure on catalyst decomposition was also examined. At higher ethylene pressure nearly quantitative formation of TpRu(CO)(η3-C4H7) was observed.},
doi = {10.1016/j.jorganchem.2017.03.051},
journal = {Journal of Organometallic Chemistry},
number = C,
volume = 847,
place = {United States},
year = {Thu Apr 13 00:00:00 EDT 2017},
month = {Thu Apr 13 00:00:00 EDT 2017}
}