Density matrix model for hydrogen transfer in the benzoic acid dimer
โ Scribed by Christoph Scheurer; Peter Saalfrank
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 552 KB
- Volume
- 245
- Category
- Article
- ISSN
- 0009-2614
No coin nor oath required. For personal study only.
โฆ Synopsis
The double hydrogen transfer in benzoic acid dimers ('the system') embedded in a crystal ('the bath') is studied with time-dependent density matrix theory. The Liouville-von Neumann equation is solved for a two-dimensional model, using a state representation for the operators, and a polynomial expansion to treat the time evolution of the reduced nuclear density matrix. The bath-induced vibrational relaxation and dephasing processes are treated within the Lindblad formalism, with interlevel transition probabilities obtained from a microscopic perturbative theory due to Meyer and Ernst. The approach of various initial non-equilibrium states towards thermal equilibrium, is monitored with the help of: (i) state populations, (ii) system-bath energy exchange, (iii) the yon Neumann and relative entropies and (iv) the decay of 'coherences'. Simulations are carried out at low and at high bath temperatures.
๐ SIMILAR VOLUMES
A single crystal pulsed neutron diffraction study of benzoic acid has been carried out at four temperatures, 20, 50, 100 and 175 K. This has allowed accurate site occupancies to be obtained for the hydrogen atom disorder in the hydrogen bonded carboxylic acid dimer motif. The temperature dependence
A precise investigation of spin-lattice relaxation rates for protons and deuterons of partially deuterated benzoic acid crystals showed a remarkable quenching of the transfer rate of an HD pair in hydrogen-bonded dimeric units of carboxyl groups with increasing concentration of D in the surrounding
The substituent effect on the single and double hydrogen atom transfer reactions in para-substituted benzoic acid isobutyl esters has been investigated by electron impact mass spectrometry. Electron-donahg substituents favour formation of the [M-C4&]+' ion generated by single hydrogen atom transfer