title: Electrochemical Oxidation and Radical Cations of Structurally Non-rigid Hypervalent Silatranes: Theoretical and Experimental Studies.
abstract: Using 18 silatranes XSi(OCH2CH2)3N (1) as examples, the potentials of electrochemical oxidation E0of the hypervalent compounds of Si were calculated for the first time at the ab initio and DFT levels. The experimental peak potentials Ep(acetonitrile) show an excellent agreement (MAE=0.03) with the MP2//B3PW91 calculated E0(C-PCM). Radical cations of 1 reveal a stretch isomerism of the N→Si dative bond. Localization of the spin density (SD) on the substituent X and the short (s) coordination contact Si⋅⋅⋅N (dSiN<2.13 Å) along with the high five-coordinate character of Si are typical for the first isomer 1+.(s), whereas the second one, 1+.(l), has a longer (l) Si⋅⋅⋅N distance (dSiN>3.0 Å), the four-coordinate Si and the SD localized on the silatrane nitrogen atom Ns. The vertical model of adiabatic ionization (1→1+.(s)or 1→1+.(l)) was developed. It allows, in accordance with an original experimental test (electrooxidation of 1 in the presence of ferrocene), a reliable prediction of the most probable pathways of the silatrane oxidation. The reliable relationships of E0(1) with the strength characteristics of the dative contact N→Si were revealed.
authors.affiliation: A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Favorsky, 1, Irkutsk, 664033, Russian Federation.
authors.forename: Valery F
authors.initials: VF
authors.lastname: Sidorkin
authors.affiliation: A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Favorsky, 1, Irkutsk, 664033, Russian Federation.
authors.forename: Elena F
authors.initials: EF
authors.lastname: Belogolova
authors.affiliation: University of Rennes I, Molecular Chemistry and Photonics, UMR 6226 ISCR, 35042, Rennes, France.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: University of Rennes I, Molecular Chemistry and Photonics, UMR 6226 ISCR, 35042, Rennes, France.
authors.forename: Viatcheslav
authors.initials: V
authors.lastname: Jouikov
authors.affiliation: A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Favorsky, 1, Irkutsk, 664033, Russian Federation.
authors.forename: Evgeniya P
authors.initials: EP
authors.lastname: Doronina
keywords: Group 14 elements; cyclic voltammetry; density functional calculations; hypervalent compounds; silatranes