Comprehensively understanding the steric hindrance effect on the coordination sphere of Pb ions and photophysical nature of two luminescent Pb(ii)-coordination polymers.

New luminescent Pb(ii)-coordination polymers (Pb(ii)-CPs), [Pb(2-anc)] (1) and [Pb(3-qlc)(HO)] (2) (2-anc = 2-aminonicotinate, 3-qlc = 3-quinolinecarboxylate), were synthesized by a solvothermal reaction and characterized using microanalysis, IR spectrometry and thermogravimetric analysis. Single crystal structure analysis revealed that the Pb ion displays a hemi-directed coordination geometry in 1 and a holo-directed coordination geometry in 2. The difference between the coordination spheres of 1 and 2 is related to the steric hindrance effect of the ligands.