Supramolecular assembly of two two-folded helical structures based on 2-substituted 8-hydroxyquinoline complexes

Based on two 2-substituted 8-hydroxyquinoline ligands containing single bondNO2 and single bondCl, two complexes [Co(L2)2(pyridine)2] (1) and [Cu(L3)2] (2) were synthesized and characterized with single-crystal X-ray diffractions, powder X-ray diffractions (PXRD), thermal analyses (TGA) and elemental analyses (EA). In the solid state, the supramolecular structures of 1 and 2 feature two different two-folded helical chains, which were constructed by non-covalent interactions, such as π⋯π stacking, Csingle bondH⋯π, Csingle bondH⋯O, Csingle bondCl⋯π and Cl⋯Cl interactions. The present research holds great promise in the development of novel functional helical structure, and may contribute to the understanding of helical organized systems in biology.