A new (3,3,6)-connected achiral 3D supramolecular network containing unique helical chains based on 1H-benzimidazole-5,6-dicarboxylato and Pb(II)

A new 1D Pb(II) coordination polymer, {[Pb(Hbidc)(phen)]·H2O}n (1), has been synthesized by a solvothermal method based on 1H-benzimidazole-5,6-dicarboxylato (H3bidc) and 1,10-phenanthroline (phen). Complex 1 features two types of helical chains, a 1D left- and right-handed double-stranded helical chain and a supramolecular helical chain, which interweave into a new (3,3,6)-connected achiral 3D supramolecular network. Notably, the supramolecular helical chains are induced by the different spatial orientations of the 1D double-stranded helical chains. The structure and properties of 1 have been determined by single crystal X-ray diffraction, powder X-ray diffraction (PXRD), elemental analysis (EA), thermogravimetric (TG) analysis and solid state fluorescence spectra.