Synthesis, Crystal Structure, Thermal Stability, Quantum Chemistry and Toxicity of Two Tri(2-methyl-2-Phenylpropyl)tin N-containing Heterocyclic Carboxylates

Two tri(2-methyl-2-phenylpropyl)tin N-containing heterocyclic carboxylates (PhCMe2CH2)(3)Sn[O2C(C4N2H3)] (1) and (PhCMe2CH2)(3)Sn[O2C(C7N2H5)] (2) were synthesized by the reactions of Pyrazine-2-carboxylic acid and Indazole-3-carboxylic acid with bis[tri(2-methyl-2-phenylpropyl)tin] oxide, respectively. Their structures were characterized by IR, H-1 and C-13 NMR, elemental analysis and X-ray crystal diffraction. The crystal of complex 1 belongs to monoclinic system, space group P2(1)/n, a=1.209 31(7) nm, b=1.818 15(11) rum c=1.491 39(9) nm, beta=93.567(3)degrees, Z=4, V=3.272 8(3) nm(3), D-c=1.302 Mg.m(-3), mu(Mo K alpha)=0.812 mm(-1), F(000)=1 328, R-1=0.027 5, wR(2)=0.067 0. However, the crystal of complex 2 belongs to triclinic system, space group P (1) over bar, a=1.153 10(7) nm, b=1.819 73(11) nm, c=2.620 40(16) nm, alpha=86.866(2)degrees, beta=87.063(2)degrees, gamma=73.332(2)degrees, Z=6, V=5.255 9(6) nm(3), D-c=1.288 Mg.m(-3), mu(Mo K alpha)=0.762 mm(-1), F(000)=2 112, R-1=0.037 4, wR(2)=0.092 5. The central tin atoms of them are aberrant tetrahedral configurations. A trimeric structure of complex 2 is formed by intermolecular C-H center dot center dot center dot O and N-H center dot center dot center dot N interactions, and a hexameric structure of complex 2 is further generated by C-H center dot center dot center dot pi interactions between two adjacent trimers. Thermogravimetric analysis shows these complexes displayed good thermal stability, and were stable up to 210 or 240 degrees C, respectively. The preliminary tests showed the complexes revealed weak toxicity against local snail, and the toxicity of complex 1 was less than that of complex 2 and bis [tri(2-methyl-2-phenylpropyl)tin] oxide. It may mean that the complexes are of good environmental compatibility. CCDC: 956893, 1; 956892, 2.