Portal de Periódicos da CAPES

An NMR study of a 13 C‐labeled hypervalent (10‐C‐5) [1] pentacoordinate carbon species

1993; Wiley; Volume: 4; Issue: 2-3 Linguagem: Inglês

10.1002/hc.520040205

1098-1071

T. R. Forbus, J. C. Martin,

Coordination Chemistry and Organometallics

Abstract Removal of two electrons from 1,8‐bis(4‐methylphenylthio)‐9‐(2, 6‐dimethoxyphenyl‐1‐ 13 C)‐10‐phenylanthracene (2) provides stable dication 1 . Isotopic enrichment (85%) of 13 C at the labeled site of the aromatic carbon, between the two sulfurs, makes possible the observation of spin‐spin coupling constants between this 13 C‐carbon and the directly bonded equatorial ligand carbons. The magnitudes of these coupling constants (two 1 J C1′C2′ = 61.9 Hz and one 1 J C1′C9 = 56.3 Hz) suggest that this carbon is sp 2 hybridized, with the postulated trigonal bipyramidal (TBP) geometry about this carbon center. The 13 C NMR chemical shifts for the 10‐C‐5 carbon ( δ 109.3) and for other carbons provide strong evidence against alternative structures for this dication. The data are consistent with the 10‐C‐5 species, with apical sulfonium ligands and equatorial carbons of the hypervalent TBP carbon species 1 .