Syntheses and crystal structures of two isomeric crown ether lead (II) bis(dithiolate) complexes [K(18C6)]2[Pb(i-mnt)2]

Two isomeric crown ether lead (II) bis(dithiolate) complexes with the same chemical formula of [K(18C6)]2[Pb(i-mnt)2] (i-mnt=1,1-dicyanoethylene-2,2-ditholate) were synthesized and characterized by elemental analysis, FT-IR spectra and single crystal X-ray diffraction. 1 crystallizes in the triclinic, space group Pī and 2 crystallizes in the monoclinic, space group P21/c. Complexes 1 and 2 both consist of two [K(18C6)]+ complex cations and one [Pb(i-mnt)2] anion and every two complex molecules form a dimer through two intermolecular Pb···S interactions. However, the molecular structures of 1 and 2 are isomeric, which leads to their different polymeric superstructures, i.e. the 1D chain structure of 1 and the 2D network structure of 2, both constructed by intermolecular K-N and Pb···S interactions.