Structural diversity of five new bitriazole-based complexes: luminescence, sorption, and magnetic properties

Employing an uninvestigated eight N-donor bitriazole ligand, 5'-(pyrazin-2-yl)-2H,4'H-3,3'-bi(1,2,4-triazole) (H2pzbtz), five complexes, {[Zn2(pzbtz)(SO4)(H2O)2]·2H2O}n (), {[Cd(pzbtz)]·3H2O}n (), [Zn3(Hpzbtz)2(SO4)2(H2O)6] (), [Co(Hpzbtz)2(H2O)2] () and {[Co2(pzbtz)2(H2O)2]·4H2O}n (), have been solvothermally synthesised by altering the reaction solvents and temperatures. Complex shows a three-dimensional (3D) framework with a very rare (3,5)-connected fsc-3,5-Cmce-2 topology. Complex exhibits a (4,4)-connected 3D pts framework with 1D channels. Complexes and are discrete trinuclear and mononuclear molecules, respectively. Complex presents a chiral 3D framework based on a novel trinuclear Co3(tr)4 cluster and features an unusual six-connected lcy topology. In the five complexes, H2pzbtz show a very variety of geometrical configurations and coordination modes. Due to the planarity of H2pzbtz, complexes display strong photoluminescence; in particular, features highly selective luminescent sensing for the Cu(2+) ion and nitrobenzene molecule. In addition, shows highly selective adsorption for CO2 over CH4, and exhibits antiferromagnetic exchange interactions among the Co(2+) ions.