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Cation radicals of organogermatranes
Author(s) -
Soualmi Saida,
Ignatovich Luba,
Jouikov Viatcheslav
Publication year - 2010
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.1710
Subject(s) - chemistry , delocalized electron , acetonitrile , electron paramagnetic resonance , crystallography , radical , trigonal bipyramidal molecular geometry , atom (system on chip) , aryl , spectroscopy , density functional theory , computational chemistry , photochemistry , crystal structure , nuclear magnetic resonance , organic chemistry , physics , alkyl , quantum mechanics , computer science , embedded system
Cation radicals (CRs) of 1‐substituted germatranes were generated by one‐electron electrochemical oxidation and studied by real‐time EPR spectroscopy for the first time. In contrast to CRs of trialkylamines, the CRs of germatranes are much more stable and can be observed in acetonitrile solution at 253 K. As follows from g ‐factors and hfc constants, spin density in the CRs of aryl germatranes is localized mainly on the axially directed p z orbital of N atom, pointed inside the atrane cage. EPR spectroscopy and Fermi contact coupling from DFT B3LYP/LANL2DZ calculations reveal an interesting feature: no contribution from the Ge atom was found in the spin delocalization in these species. Contrary to the neutral germatranes and to what was expected from the qualitative estimations, the nitrogen atom in the CR does not adopt an exo ‐configuration and is practically planar. Experimental hfc constants and DFT B3LYP/LANL2DZ calculations support the observed feature: the geometry around the N atom in CR is close to planar whereas the Ge atom undergoes remarkable reorganization, approaching a trigonal bipyramid in benzyl germatranes and tetrahedral configuration in aryl germatranes. 1‐Substitution of germatranes with the groups with low own ionization potential (R 2 NC 6 H 4 ‐, where R = Me, Et) inverts the roles of the fragments—upon electrooxidation, these compounds behave as corresponding germatranyl‐substituted organic derivatives. Copyright © 2010 John Wiley & Sons, Ltd.