Synthesis, structure and thermal behaviors of a magnesium(II) complex with tetrazole-1-acetic acid

A new complex of magnesium with tetrazole-1-acetic acid (tza) has been synthesized and characterized by elemental analysis and FT-IR spectrum. Single-crystal X-ray diffraction analysis determined the molecular formula as Mg(tza)2(H2O)4. The crystal belongs to the triclinic system with P1 space group, and a=6.133(2), b=6.488(2), c=10.0127(7) , α=77.282(10), =91.558(1), =76.002(8), V=349.0(2) 3, Z=1, C6H14MgN8O8, Mr=350.56, Dc=1.668 gcm-3, F(000)=182, μ=0.189, S=1.000, the final R=0.0294 and wR=0.0785 for 1128 observed reflections with I > 2(I). In this molecule, the tza ion exhibits an infrequent monodentate coordination mode. The magnesium center is hexa-coordinated to a slightly distorted octahedral configuration by six oxygen atoms from two tza ligands and four coordinated water molecules. DSC and TG-DTG analyses were applied to assess the thermal decomposition behavior. The kinetic parameters of the exothermal peak were calculated by non-isothermal reaction kinetics. The values of critical temperature of thermal explosion, ?S?, ?H? and ?G?, were obtained as 596 K, -42.25 J mol-1 K-1, 296.43 kJ mol-1 and 323.53 kJ mol-1, respectively.