S-(+)-(E)-1-(2-furfuryl)-5-substituted-1,3,5-hexahydrotriazine-2-N-nitroimines: Synthesis, Crystal Structure and DFT Calculations

A novel neonicotinoid analogue (C13H19N5O5, 3a) had been synthesized, the structure was characterized by elemental analysis, IR and H-1 NMR spectra, and the S-(+)-(E)configuration was confirmed by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P2(1) with a = 8.7076(17), b = 8.3211(17), c = 10.642(2) angstrom, beta = 92.370(3)degrees, V = 770.4(3) angstrom(3), Z = 2, D-c = 1.402 g/cm(3), mu = 0.110 mm(-1), M-r = 325.33, F(000) = 344, S = 1.027, R = 0.0543 and wR = 0.1229 for 3601 unique reflections with 2919 observed ones (I > 2 sigma(I)). Compound 3a is stabilized by intramolecular hydrogen bonds and intermolecular force. In addition, the structure of compound 3a was optimized by the B3LYP/6-31G(d, p). DFT/B3LYP optimizations were performed based on X-ray geometries applying 6-31G(d, p) basis set. The optimized structure of compound 3a by the B3LYP/6-31G(d,p) method is more bent than in the crystal. IR spectrum of the solid compound is consistent with the X-ray structure. The HOMO-LUMO gap in 3a (5.3 eV) indicates high kinetic stabilities of compound 3a. The preliminary bioassay test showed that 3a exhibited good activities against Nilaparvata legen, Pseudaletia separate Walker and Aphis medicagini at 500 mg/L.