Heteroaromatic substituted diimidosulfinates

Coupling of two diimidosulfinate units via a conjugated organic substituent to facilitate electronic communication between the two S(NR)2-moieties seems advantageous because polyimido sulfur compounds are exposed to SET processes. The coupling might facilitate electron transport. In this paper we present the syntheses and crystal structures of the heteroaromatic S-substituted metal diimidosulfinates [(thf)Li2{(H3CNC4H3)S(NtBu)2}2] (1), [(tmeda)Li{(SC8H5)S(NtBu)2}] (2), [Fe{(SC8H5)S(NtBu)2}2] (3), and [Cu{(SC8H5)S(NtBu)2}]2 (4), as potential starting materials. As the structural investigation shows that electronic communication between the S(NR)2-moiety and a S-bonded conjugated organic substituent is only feasible when the aromatic perimeter is arranged strictly in-plane to one S–N bond as observed in 1. Here the ring nitrogen atom is blocked against metal coordination. In the other complexes in-plane arrangement of the S-heteroaromatic substituent is precluded even by very weak metal coordination of the ring sulfur atom. The (N,N)-chelating lithium (2) and iron (3) coordination forces the ring in a more or less orthogonal arrangement relative to the SN2-plane. The ring-S⋯copper coordination in 4, which could have forced the heteroarene ring into the plane of one S–N bond, apparently is to weak to turn the ring about the S–C(sp2) bond.