Synthesis, crystal structures and vapor adsorption properties of Hg(II) and Cd(II) coordination polymers derived from two hydrazone Schiff base ligands.

• Four 1D coordination polymers have been synthesized and characterized. • The ligands show different coordination sites in coordination polymers. • Methanol vapor adsorption for the four complexes was measured. Four coordination polymers, [Hg L1 Br 2 ] n (1), {[Cd(L1) 2 Cl 2 ]·2CH 3 OH} n (2), [Hg L2 Cl 2 ] n (3) and [Cd(L2) 2 Cl 2 ] n (4), have been synthesized and characterized from two hydrazone Schiff base ligands (L1 and L2) with mercury(II) or cadmium(II) halide, respectively. In complexes 1 and 3 , each mercury(II) center is five-coordinated with distorted square pyramidal geometry in 1D coordination polymers. In complexes 2 and 4 , each cadmium(II) center is six-coordinated with slightly distorted octahedral geometry in 1D looped-chain structures. Interestingly, the ligands show different coordination sites in the formation of coordination polymers. In complexes 2 , 3 and 4 , the ligands coordinate to the metal centers by pyridine nitrogen atoms and amino nitrogen atoms, whereas in complex 1 it coordinates by pyridine nitrogen atoms and carbonyl oxygen atoms instead of amino nitrogen atoms. [ABSTRACT FROM AUTHOR]