D/L-mandelic acid-based three new Pb(II) coordination polymers: Influence of temperature and 5,5′-dimethyl-2,2′-dipyridyl ancillary ligand on constructuring enantiomeric coordination polymers

[Display omitted] •The influence of temperature on constructuring enantiomeric coordination polymers.•The influence of ancillary ligand on constructuring enantiomeric coordination polymers.•The luminescent properties of enantiomeric coordination polymers in the solid state. Three new Pb(II) coordination polymers, namely [Pb2(mand)2]n (1), {[Pb(L-Hmand)(NO3)(5,5′-DM-2,2′-bipy)]·2H2O}n (2-L), {[Pb(D-Hmand)(NO3)(5,5′-DM-2,2′-bipy)]·2H2O}n (2-D) (H2mand = D/L-mandelic acid, 5,5′-DM-2,2′-bipy = 5,5′-dimethyl-2,2′-bipyridyl), have been prepared. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, powder X-ray diffraction and thermogravimetric analyses. Complex 1 crystallizes in the triclinic system with space group P-1, and displays a 2D layer structure. Complexes 2-L and 2-D are pairs of enantiomers. They crystallize in the same chiral space group P212121 and feature a 1D chain structure. The influence of the temperature and steric-hinerance of 5,5′-dimethyl-2,2′-dipyridyl molecules on constructing enantiomeric Pb(II) coordination polymers based on chiral mandelic acid ligands have been demonstrated. In addition, the circular dichroism (CD) spectroscopy of 2-L and 2-D exhibit obvious positive or negative Cotton effects indicating their homochirality. The luminescent properties of 1, 2-L and 2-D in the solid state have also been investigated.