Autor: |
Romanovs, Vitalijs, Spura, Jana, Jouikov, Viatcheslav |
Předmět: |
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Zdroj: |
Synthesis; 2018, Vol. 50 Issue 18, p3679-3685, 7p, 5 Diagrams |
Abstrakt: |
Novel fused bis-germatranes containing three hypercoordinated atoms (two Ge and one N) and substituted at the 1,1′-positions with bromo-thienyl groups [(3-bromo-2-thienyl)-, (3,5-dibromo-2-thienyl)-, and 3-(4-bromo)-2-thienyl] have been synthesized from the corresponding triethoxy(thienyl)germanes and tris(1,3-dihydroxypropan-2-yl)amine. The doubly degenerated HOMO and HOMO-1 in these compounds are localized on the thienyl substituents while a 5c-6e hyperbond of the bis-germatranyl core (C–Ge←N→Ge–C system) is only a lower lying HOMO-2. Square-wave pulse voltammetry in CH3CN/0.1 M Bu4NPF6 shows all three compounds to undergo reversible electrochemical oxidation affecting one thienyl substituent. The DFT B3LYP/Lanl2DZ//HF/6-311G(d,p) calculations of their cation radicals suggest the enhancement and shortening of the N→Ge intramolecular dative bond on the side of the oxidized thienyl unit because of the positive charge and the increased acceptor character of the latter; this is accompanied by the loss of the N→Ge dative bond on the side of the non-oxidized substituent and a substantial pyramidalization of the Ge atom. [ABSTRACT FROM AUTHOR] |
Databáze: |
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