title: Theoretical calculation of reorganization energy for electron self-exchange reaction by constrained density functional theory and constrained equilibrium thermodynamics.
abstract: Within the framework of constrained density functional theory (CDFT), the diabatic or charge localized states of electron transfer (ET) have been constructed. Based on the diabatic states, inner reorganization energy λin has been directly calculated. For solvent reorganization energy λs, a novel and reasonable nonequilibrium solvation model is established by introducing a constrained equilibrium manipulation, and a new expression of λs has been formulated. It is found that λs is actually the cost of maintaining the residual polarization, which equilibrates with the extra electric field. On the basis of diabatic states constructed by CDFT, a numerical algorithm using the new formulations with the dielectric polarizable continuum model (D-PCM) has been implemented. As typical test cases, self-exchange ET reactions between tetracyanoethylene (TCNE) and tetrathiafulvalene (TTF) and their corresponding ionic radicals in acetonitrile are investigated. The calculated reorganization energies λ are 7293 cm(-1) for TCNE/TCNE(-) and 5939 cm(-1) for TTF/TTF(+) reactions, agreeing well with available experimental results of 7250 cm(-1) and 5810 cm(-1), respectively.
authors.affiliation: College of Chemistry, Sichuan University, Chengdu 610064, China.
authors.forename: Hai-Sheng
authors.initials: HS
authors.lastname: Ren
authors.forename: Mei-Jun
authors.initials: MJ
authors.lastname: Ming
authors.forename: Jian-Yi
authors.initials: JY
authors.lastname: Ma
authors.forename: Xiang-Yuan
authors.initials: XY
authors.lastname: Li
mesh_terms: D004583:Electrons; D005030:Ethylenes / Q000737:chemistry*; D006571:Heterocyclic Compounds / Q000737:chemistry*; D015394:Molecular Structure; D009570:Nitriles / Q000737:chemistry*; D011789:Quantum Theory; D013816:Thermodynamics
chemical_list: D005030:Ethylenes; D006571:Heterocyclic Compounds; D009570:Nitriles; C003393:tetracyanoethylene; C063887:tetrathiafulvalene