- 作者: 陳錦明 ; 牟中原 ; 林聖賢
- 作者服務機構: 台灣大學化學系
- 中文摘要:
We present a simple quantum mechanical model for solvent bridge-mediated long-range nonadiabatic electron-transfer reaction rate. A perturbation theory using a one-electron model is employed to treat the electronic transition element that includes donor, acceptor and bridge unit wave functions. Reaction-coordinate activation is treated by high-temperature approximation. The pre-exponential factor in the rate coefficient becomes dependent on the distance between donor and acceptor; the decay length depends strongly on the driving force and is effective at a large range if the level of energy of the donor is nearly that of the bridge. This condition is satisfied for a process of electron transfer with excited donor molecules or in the highly exothermic regime.
According to a simple model calculation, the non-existence of an "inverted" regime in highly exothermic reaction is favored for solvent media with large relative permittivity and low-lying HOMO (highest occupied molecular orbital) or LUMO (lowest unoccupied molecular orbital). In the normal regime in which the driving force(.DELTA.G.degree.) is positive or nearly zero this effect at large-range is negligible, and transfer of the electron occurs mostly at the distance of contact. - 英文摘要: --
- 中文關鍵字: Electron Transfer Reaction; Solvent Effect; One Electron Model; Wave Function; Molecular Orbital; Perturbation Theory
- 英文關鍵字: 電子轉移反應;溶劑效應;單一電子模型;波函數;分子軌域;微擾理論