Nonempirical ab initio studies on inner-sphere reorganization energies of M2+(H2O)6/M3+(H2O)6 redox couples at valence basis level

✍ Scribed by Yuxiang Bu; Yangjun Ding; Faxin He; Lifu Jiang; Xinyu Song

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 179 KB
• Volume: 61
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/(sici)1097-461x(1997)61:1<117::aid-qua14>3.0.co;2-b

✦ Synopsis

On the basis of the basic feature of the electron transfer reactions, a new theoretical scheme and application of a nonempirical ab initio method in computing the inner-sphere Ž . reorganization energies RE of hydrated ions in electron transfer processes in solution Ž . are presented at valence STO basis VSTO level. The potential energy surfaces and the various molecular structural parameters for transition metal complexes are obtained Ž . using nonempirical molecular orbital MO calculations, and the results agree very well with experimentally observed ones from vibrational spectroscopic data. The results of inner-sphere REs obtained from these calculations via this new scheme give a good agreement with photoemission experimental findings and those from the improved 2q Ž . 3 q Ž . Ž self-exchange model proposed early for M H O rM H O MsV, Cr, Mn, Fe, 2 6 2 6

. and Co redox couple systems and are better than those from semiempirical INDOrII MO method and other classical methods. Further, the observed agreement of the optimized structural data and the results of inner-sphere REs of complexes with Ž . experimental findings confirms the following: 1 the validity of nonempirical MO calculation method to get accurate structural parameters and inner-sphere RE for the Ž . redox systems for which reliable vibrational spectroscopic data are not available, 2 the Ž . validity of the improved self-exchange model proposed early for inner-sphere RE, and 3 the reasonableness of some approximations adopted in this study.