Understanding the factors affecting the activation of alkane by Cp ' Rh(CO)(2) (Cp ' = Cp or Cp*)
2010
Autori
George, Michael W.Hall, Michael B.
Jina, Omar S.
Portius, Peter
Sun, Xue-Zhong
Towrie, Michael
Wu, Hong
Yang, Xinzheng
Zarić, Snežana D.
Članak u časopisu (Objavljena verzija)
Metapodaci
Prikaz svih podataka o dokumentuApstrakt
Fast time-resolved infrared spectroscopic measurements have allowed precise determination of the rates of activation of alkanes by Cp'Rh(CO) (Cp' = eta(5)-C5H5 or eta(5)-C5Me5). We have monitored the kinetics of C-H activation in solution at room temperature and determined how the change in rate of oxidative cleavage varies from methane to decane. The lifetime of CpRh(CO)(alkane) shows a nearly linear behavior with respect to the length of the alkane chain, whereas the related Cp*Rh(CO)(alkane) has clear oscillatory behavior upon changing the alkane. Coupled cluster and density functional theory calculations on these complexes, transition states, and intermediates provide the insight into the mechanism and barriers in order to develop a kinetic simulation of the experimental results. The observed behavior is a subtle interplay between the rates of activation and migration. Unexpectedly, the calculations predict that the most rapid process in these Cp'Rh (CO)(alkane) systems is the 1,3-...migration along the alkane chain. The linear behavior in the observed lifetime of CpRh(CO)(alkane) results from a mechanism in which the next most rapid process is the activation of primary C-H bonds (-CH3 groups), while the third key step in this system is 1,2-migration with a slightly slower rate. The oscillatory behavior in the lifetime of Cp*Rh(CO)(alkane) with respect to the alkane's chain length follows from subtle interplay between more rapid migrations and less rapid primary C-H activation, with respect to CpRh(CO)(alkane), especially when the CH3 group is near a gauche turn. This interplay results in the activation being controlled by the percentage of alkane conformers.
Ključne reči:
organometallic / photochemistry / computation / transition metal / sigma complexIzvor:
Proceedings of the National Academy of Sciences of the United States, 2010, 107, 47, 20178-20183Izdavač:
- Natl Acad Sciences, Washington
Finansiranje / projekti:
- Proučavanje odnosa reaktivnosti, nekovalentnih interakcija i strukture molekula i modelovanje hemijskih sistema (RS-MESTD-MPN2006-2010-142037)
- European Union, FP6-502440
- Welch Foundation [A-0648]
- National Science Foundation [CHE-0910552, CHE-0518074, CHE-0541587, DMS-0216275]
- Wolfson Merit Award
- Engineering and Physical Sciences Research Council
DOI: 10.1073/pnas.1001249107
ISSN: 0027-8424
PubMed: 21048088
WoS: 000284529000010
Scopus: 2-s2.0-78650585987
Kolekcije
Institucija/grupa
Hemijski fakultet / Faculty of ChemistryTY - JOUR AU - George, Michael W. AU - Hall, Michael B. AU - Jina, Omar S. AU - Portius, Peter AU - Sun, Xue-Zhong AU - Towrie, Michael AU - Wu, Hong AU - Yang, Xinzheng AU - Zarić, Snežana D. PY - 2010 UR - https://cherry.chem.bg.ac.rs/handle/123456789/1136 AB - Fast time-resolved infrared spectroscopic measurements have allowed precise determination of the rates of activation of alkanes by Cp'Rh(CO) (Cp' = eta(5)-C5H5 or eta(5)-C5Me5). We have monitored the kinetics of C-H activation in solution at room temperature and determined how the change in rate of oxidative cleavage varies from methane to decane. The lifetime of CpRh(CO)(alkane) shows a nearly linear behavior with respect to the length of the alkane chain, whereas the related Cp*Rh(CO)(alkane) has clear oscillatory behavior upon changing the alkane. Coupled cluster and density functional theory calculations on these complexes, transition states, and intermediates provide the insight into the mechanism and barriers in order to develop a kinetic simulation of the experimental results. The observed behavior is a subtle interplay between the rates of activation and migration. Unexpectedly, the calculations predict that the most rapid process in these Cp'Rh (CO)(alkane) systems is the 1,3-migration along the alkane chain. The linear behavior in the observed lifetime of CpRh(CO)(alkane) results from a mechanism in which the next most rapid process is the activation of primary C-H bonds (-CH3 groups), while the third key step in this system is 1,2-migration with a slightly slower rate. The oscillatory behavior in the lifetime of Cp*Rh(CO)(alkane) with respect to the alkane's chain length follows from subtle interplay between more rapid migrations and less rapid primary C-H activation, with respect to CpRh(CO)(alkane), especially when the CH3 group is near a gauche turn. This interplay results in the activation being controlled by the percentage of alkane conformers. PB - Natl Acad Sciences, Washington T2 - Proceedings of the National Academy of Sciences of the United States T1 - Understanding the factors affecting the activation of alkane by Cp ' Rh(CO)(2) (Cp ' = Cp or Cp*) VL - 107 IS - 47 SP - 20178 EP - 20183 DO - 10.1073/pnas.1001249107 ER -
@article{ author = "George, Michael W. and Hall, Michael B. and Jina, Omar S. and Portius, Peter and Sun, Xue-Zhong and Towrie, Michael and Wu, Hong and Yang, Xinzheng and Zarić, Snežana D.", year = "2010", abstract = "Fast time-resolved infrared spectroscopic measurements have allowed precise determination of the rates of activation of alkanes by Cp'Rh(CO) (Cp' = eta(5)-C5H5 or eta(5)-C5Me5). We have monitored the kinetics of C-H activation in solution at room temperature and determined how the change in rate of oxidative cleavage varies from methane to decane. The lifetime of CpRh(CO)(alkane) shows a nearly linear behavior with respect to the length of the alkane chain, whereas the related Cp*Rh(CO)(alkane) has clear oscillatory behavior upon changing the alkane. Coupled cluster and density functional theory calculations on these complexes, transition states, and intermediates provide the insight into the mechanism and barriers in order to develop a kinetic simulation of the experimental results. The observed behavior is a subtle interplay between the rates of activation and migration. Unexpectedly, the calculations predict that the most rapid process in these Cp'Rh (CO)(alkane) systems is the 1,3-migration along the alkane chain. The linear behavior in the observed lifetime of CpRh(CO)(alkane) results from a mechanism in which the next most rapid process is the activation of primary C-H bonds (-CH3 groups), while the third key step in this system is 1,2-migration with a slightly slower rate. The oscillatory behavior in the lifetime of Cp*Rh(CO)(alkane) with respect to the alkane's chain length follows from subtle interplay between more rapid migrations and less rapid primary C-H activation, with respect to CpRh(CO)(alkane), especially when the CH3 group is near a gauche turn. This interplay results in the activation being controlled by the percentage of alkane conformers.", publisher = "Natl Acad Sciences, Washington", journal = "Proceedings of the National Academy of Sciences of the United States", title = "Understanding the factors affecting the activation of alkane by Cp ' Rh(CO)(2) (Cp ' = Cp or Cp*)", volume = "107", number = "47", pages = "20178-20183", doi = "10.1073/pnas.1001249107" }
George, M. W., Hall, M. B., Jina, O. S., Portius, P., Sun, X., Towrie, M., Wu, H., Yang, X.,& Zarić, S. D.. (2010). Understanding the factors affecting the activation of alkane by Cp ' Rh(CO)(2) (Cp ' = Cp or Cp*). in Proceedings of the National Academy of Sciences of the United States Natl Acad Sciences, Washington., 107(47), 20178-20183. https://doi.org/10.1073/pnas.1001249107
George MW, Hall MB, Jina OS, Portius P, Sun X, Towrie M, Wu H, Yang X, Zarić SD. Understanding the factors affecting the activation of alkane by Cp ' Rh(CO)(2) (Cp ' = Cp or Cp*). in Proceedings of the National Academy of Sciences of the United States. 2010;107(47):20178-20183. doi:10.1073/pnas.1001249107 .
George, Michael W., Hall, Michael B., Jina, Omar S., Portius, Peter, Sun, Xue-Zhong, Towrie, Michael, Wu, Hong, Yang, Xinzheng, Zarić, Snežana D., "Understanding the factors affecting the activation of alkane by Cp ' Rh(CO)(2) (Cp ' = Cp or Cp*)" in Proceedings of the National Academy of Sciences of the United States, 107, no. 47 (2010):20178-20183, https://doi.org/10.1073/pnas.1001249107 . .