Novel Zn (II) and Pb (II) coordination networks with large circuits: Synthesis, crystal structures and self-focusing effects

2-D polymers {[Zn(btx)2(NO3)2]}n (1) and {[Pb(btx)1.5(NCS)]NO3}n (2) (btx = 1,4-bis(triazol-1-ylmethyl)benzene) with large circuits are synthesized and their third-order NLO properties are investigated. We found that the effects of metal ions on the third-order NLO properties of polymers 1 and 2 are weak, and the effects of ligand are crucial.