Quantitative study and visualization of spherical 2( N + 1) 2 homoaromaticity by through space NMR shieldings (TSNMRS)

Abstract

The through space NMR shielding (TSNMRS) values of adamantane, the 2( N + 1) 2 spherical (4c, 2e) homoaromatic compounds 1,3-dehydro-5,7-adamantandiyl dication ( C 10 H 12 2 + ) and 1,3-dehydro-5,7-cubandiyl dication ( C 8 H 4 2 + ), and the (6c, 8e) homoaromatic compound 2,2′,4,4′,6,6′,8,8′,10,10′-dehydroadamantane tetracation ( C 10 H 4 4 + ) have been ab initio calculated, employing the NICS concept, and visualized as iso-chemical shielding surfaces (ICSSs). TSNMRS values can be successfully employed to study both the endohedral and exohedral aromaticity/antiaromaticity of the compounds studied.