Structure-Directing Interplay between Tetrel and Halogen Bonding in Co-Crystal of Lead(II) Diethyldithiocarbamate with Tetraiodoethylene

The co-crystallization of the lead(II) complex [Pb(S(2)CNEt(2))(2)] with tetraiodoethylene (C(2)I(4)) gave the co-crystal, [Pb(S(2)CNEt(2))(2)]∙½C(2)I(4), whose X-ray structure exhibits only a small change of the crystal parameters than those in the parent [Pb(S(2)CNEt(2))(2)]. The supramolecular organization of the co-crystal is largely determined by an interplay between Pb⋯S tetrel bonding (TeB) and I⋯S halogen bonding (HaB) with comparable contributions from these non-covalent contacts; the TeBs observed in the parent complex, [Pb(S(2)CNEt(2))(2)], remain unchanged in the co-crystal. An analysis of the theoretical calculation data, performed for the crystal and cluster models of [Pb(S(2)CNEt(2))(2)]∙½C(2)I(4), revealed the non-covalent nature of the Pb⋯S TeB (−5.41 and −7.78 kcal/mol) and I⋯S HaB (−7.26 and −11.37 kcal/mol) interactions and indicate that in the co-crystal these non-covalent forces are similar in energy.