Synthesis And Properties Of Complexes Containing Nitrogen - Containing Heterocyclic Ligands

In recent years, the considerable interest has focused on coordination polymers (CPs), not only owing to their fascinating geometry structures, as well as because of their potential application in catalysis, gas adsorption and separation, drug delivery, electronic, magnetic and fluorescent sensing. Studies showed that the employment of various organic ligands is effective synthetic strategy to construct charming CPs. In addition to pure carboxylate ligands, N-containing heterocyclic (pyridine, imidazole, triazole, tetrazole) multidentate ligands can also synthesis excellent CPs. Due to the diversity of coordination model for the N-containing heterocyclic multidentate ligand, these complexes show the diversity of structure.In this context, the author have selected flexible 3,3’,5,5’-tetramethyl-4,4’-bipyrazole (H2bpz) and multidentate bi-1,2,4-triazole derivative 5’-(pyrazin-2-yl)-2H,4’H-3,3’-bi(1,2,4-triazole) (H2pzbtz) to construct coordination polymers, respectively. Under the solvothermal reaction, the eleven CPs were obtained: [Ag4(H2bpz)4(SO4)2]·H2O (1), [Ag2(H2bpz)2(SO4)]·3H2O (2), [Ag3(H2bpz)4](SO4)2/3(OH)5/3·4H2O (3),{[Zn2(pzbtz)(SO4)(H2O)2]·2H2O}n (4), {[Cd(pzbtz)]·3H2O}n (5), [Zn3(Hpzbtz)2(SO4)2(H2O)6] (6), [Co(Hpzbtz)2(H2O)2] (7), {[Co2(pzbtz)2(H2O)2]·4H2O}n (8),{[Mn3(pzbtz)2(Cl)2(H2O)2]·4H2O}n (9), {[Mn3(pzbtz)3(H2O)3]·2H2O·1.5DMA}n (10) (DMA = N,N-Dimethylacetamide), {[Mn2(pzbtz)(SO4)(H2O)3]·3H2O}n (11). The structures of all complexes have been determined by X-ray single crystal diffraction. Complexes 1 and 2 are structural isomers, in which 1 exhibits a 2-fold interpenetrated (3,5)-connected hms net, and 2 is a 3-connected ths net containing interesting 3-fold and 2-fold heterochiral helical chains. Complex 3 is a rare 2D+2D+2D → 3D polycatenating porous framework based on interpenetration of three sets of layers, featuring an unprecedented d-d-d interpenetration mode, such an unusual polycatenation leads to intriguing structure. Complex 4 shows the uncommon (3,5)-connected fsc-3,5-Cmce-2 topology,5 is a binodal (4,4)-connected pts net, Complexes 6 and 7 are discrete trinuclear and mononuclear molecules, respectively. Complex 8 presents a chiral framework based on a novel trinuclear Co3(tr)4 cluster and features an unusual 6-connected Icy topology. Complex 9 is a three-dimensional (3D) framework with a similar paddlewheel SBU. Complex 10 shows a 3D framework based on a novel tetranuclear Mn4(tr)6 cluster. Complex 11 is a 3D framework with a 1D channels. All complexes have been characterized by power X-ray diffraction (PXRD), elemental analyses, IR spectra and thermogravimetric analysis (TGA). The luminescence, magnetic and adsorption properties of some complexes have also been tested and investigated mainly.