Syntheses, Structures And Properties Of Tetrazole And Triazole Derivatives Based Complexes

The properties of functional materials depend much on their structures and compositions.Structure-properties relationship research provides an important reference for the design andsynthesis of functional materials, making the designed assembly of new molecular basedmaterials with expected properties become possible. In this paper, fourteen new complexesZn₂（5-ATA）₃（HCOO）（1）,{[Zn₂（μ₄-SO4）（μ₃-OH）（5-ATA）（NH₃）]·2H₂O}n（2）,{[Zn（2,2’-bpy）₃]（trans-AT）_0.5NO₃·6H₂O}（3）,{[Ni（2,2’-bpy）₃]₂（cis-AT）（trans-AT）·10H₂O}（4）,{[M（en）₂（trans-AT）₂]（trans-H₂en）·2H₂O}（M=Zn,5; Ni,6; Cu,7）,{[Co（en）₃]₂（AT）₃·3H₂O}（8）,{[Ni（en）₂（trans-AT）]（trans-AT）（trans-H₂en）·2H₂O}（9）,{[Cu（en）₂（trans-AT）]·2H₂O}（10）,{[Cu（en）₂（trans-AT）_0.5]（trans-AT）_0.5}（11）,[Cd₂（H₂ATSA）₄]·13H₂O（12）,{[Mn（4,4’-bpy）₂-（H₂O）₄]（4,4’-bpy）₂（H₂ATSA）₂·7H₂O}（13）,[Mn₇（BTA）₆（OH）₂（H₂O）₁₂]（14），（5-ATA=5-amino-tetrazole, AT=5,5’-azotetrazolate, H₃ATSA=5-azotriazolyl salicylic acid,2,2’-bpy=2,2’-bipyridine, en=ethylenediamine,4,4’-bpy=4,4’-bipyridine） have been synthesized andcharacterized by single crystal X-ray diffraction analysis, elemental analysis, IR and UV-visspectroscopy, thermogravimetric （TG） analysis, luminescence spectroscopy and confocal laserscanning microscope.Complex1displays a four-connected2D bilayer honeycomb network and the2D bilayersfurther pack into3D porous supramolecular structure via strong π-π stacking interactionsbetween the neighboring5-ATA-ligands.2features a3D porous structure in which both5-ATA-and SO42-anions act as μ₄bridging ligands. In3, a novel1D water chain, which isformed by a planar bicyclo[5.5.0] decameric water cluster of （H₂O）₁₂linking each otherthrough the O···O mono hydrogen bond, is observed. In4, both trans and cis isomers of AT^2-anions are observed, and the cis isomers are nonplanar with the dihedral angle between twotetrazolate rings of about87°and show a nearly vertical point-to-face structure. In5-11, thetrans-AT^2-anions show four different coordinating modes and unusual face-to-face AT^2--AT^2-π--π-stacking interactions with the separated interplanar center to center distances ranging from3.32to4.0are observed.5-11display3D supramolecular structures and the π--π-stacking,hydrogen bonding and electrostatic inteactions are responsible for the stabilization of the3D supramolecular structures.12is1D chain structure with H₂ATSAanions as bidentate ligandsand13is0D structure with H₂ATSA anions as free counter-ions. The H₂ATSA anion in12and13exhibits trans-enol-E configuration, which is different from the trans-enol-Zconfiguration of the neutral H₃ATSA molecule.The aqueous solutions of6-11show photochromism that originates from the trans-cisisomerisation of AT^2-anionic ligands and can be employed as imaging agents for labeling onioncell under laser excitation although their photoluminescences are very weaker. The solidsamples of complexes3,5emit simultaneously green and red multi-photoluminescence underlaser excitation. The yellow crystal powder samples for H₃ATSA and12show a coincidentmaximum absorption band at427nm though the neutral H₃ATSA molecule and the H₂ATSA anion in12exhibit two different configuration. Moreover, the crystal powder samples of3,5,H₃ATSA and12display very larger Stokes’s characteristic photoluminescence.