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(S2CNEt2)(2)] with tetraiodoethylene (C2I4) gave the co-crystal, [Pb(S2CNEt2)(2)]center dot 1/2C(2)I(4), whose X-ray structure exhibits only a small change of the crystal parameters than those in the parent [Pb(S2CNEt2)(2)]. The supramolecular organization of the co-crystal is largely determined by an interplay between PbMIDLINE HORIZONTAL ELLIPSISS tetrel bonding (TeB) and IMIDLINE HORIZONTAL ELLIPSISS halogen bonding (HaB) with comparable contributions from these non-covalent contacts; the TeBs observed in the parent complex, [Pb(S2CNEt2)(2)], remain unchanged in the co-crystal. An analysis of the theoretical calculation data, performed for the crystal and cluster models of [Pb(S2CNEt2)(2)]center dot 1/2C(2)I(4), revealed the non-covalent nature of the PbMIDLINE HORIZONTAL ELLIPSISS TeB (-5.41 and -7.78 kcal/mol) and IMIDLINE HORIZONTAL ELLIPSISS HaB (-7.26 and -11.37 kcal/mol) interactions and indicate that in the co-crystal these non-covalent forces are similar in energy.