Mechanistic information from low-temperature rapid-scan and NMR measurements on the protonation and subsequent reductive elimination reaction of a (diimine)platinum(II) dimethyl complex

Wik BJ, Ivanovic-Burmazovic I, Tilset M, van Eldik R (2006)


Publication Type: Journal article, Original article

Publication year: 2006

Journal

Original Authors: Wik B., Ivanovic-Burmazovic I., Tilset M., Van Eldik R.

Publisher: American Chemical Society

Book Volume: 45

Pages Range: 3613-3621

Journal Issue: 9

DOI: 10.1021/ic0519537

Abstract

A detailed kinetic study of the protonation and subsequent reductive elimination reaction of a (diimine)platinum(II) dimethyl complex was undertaken in dichloromethane over the temperature range of -90 to +10°C by stopped-flow techniques. Time-resolved UV-vis monitoring of the reaction allowed the assessment of the effects of acid concentration, coordinating solvent (MeCN) concentration, temperature, and pressure. The second-order rate constant for the protonation step was determined to be 15200 ± 400 M s at -78°C, and the corresponding activation parameters are ΔH = 15.2 ± 0.6 kJ mol and ΔS = -85 ± 3 J mol K, which are in agreement with the addition of a proton that results in the formation of the platinum(IV) hydrido complex. The kinetics of the second, methane-releasing reaction step do not show an acid dependence, and the MeCN concentration also does not significantly affect the reaction rate. The activation parameters for the second reaction step were found to be ΔH = 75 ± 1 kJ mol, ΔS = +38 ± 5 J mol K, and ΔV = +18 ± 1 cm mol, strongly suggesting a dissociative character of the rate-determining step for the reductive elimination reaction. The spectroscopic and kinetic observations were correlated with NMR data and assisted the elucidation of the underlying reaction mechanism. © 2006 American Chemical Society.

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How to cite

APA:

Wik, B.J., Ivanovic-Burmazovic, I., Tilset, M., & van Eldik, R. (2006). Mechanistic information from low-temperature rapid-scan and NMR measurements on the protonation and subsequent reductive elimination reaction of a (diimine)platinum(II) dimethyl complex. Inorganic Chemistry, 45(9), 3613-3621. https://doi.org/10.1021/ic0519537

MLA:

Wik, Bror J., et al. "Mechanistic information from low-temperature rapid-scan and NMR measurements on the protonation and subsequent reductive elimination reaction of a (diimine)platinum(II) dimethyl complex." Inorganic Chemistry 45.9 (2006): 3613-3621.

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