Synthesis and theoretical studies on the vibration of a novel (3,4-disfluoro)phenylquione.

A novel (3,4-disfluoro)phenylquione (2F-PQ) was synthesized through the reaction of 3,4-Difluoroaniline and 1,4-benzoquinone. Its structure was verified by (1)H NMR, FTIR and Raman spectra. The ground-state geometries were optimized by using density functional theory (DFT) at B3LYP/6-311G+(d,p), B3PW91/6-311G+(d,p) and MPB3PW91/6-311G+(d,p) level without symmetry constrains, respectively. The predicted FTIR and Raman spectra scaled by factor are well consistent with experimental spectra.

Synthesis, crystal structure, insecticidal activity and DFT study on the geometry and vibration of O-(E)-1-{1-[(6-chloropyridin-3-yl)methyl]-5-methyl-1H-1,2,3-triazol-4-yl}ethyleneamino-O-ethyl-O-phenylphosphorothioate.

The title compound, O-(E)-1-{1-[(6-chloropyridin-3-yl)methyl]-5-methyl-1H-1,2,3-triazol-4-yl}ethyleneamino-O-ethyl-O-phenylphosphorothioate, has been synthesized via the condensation reaction of 1-{1-[(6-chloropyridin-3-yl)methyl]-5-methyl-1H-1,2,3-triazol-4-yl}ethanone oxime and O-ethyl-O-phenylphosphorochloridothioate in the presence of NaOH powder in refluxing EtOH. Its structure was characterized by (1)H NMR, FTIR, Raman, elemental analysis and X-ray single crystal diffraction. The results of preliminary bioassays indicated that the title compound displays good insecticidal activity. Density functional (DFT) calculations have been carried out for the title compound by using the Becke-Lee-Yang-Parr's three-parameter hybrid functional (B3LYP) method at 6-31G and 6-31G basis sets. The calculated results show that the predicted geometry can well reproduce the structural parameters. The vibrational wave numbers of the title compound were calculated at same level. Predicted vibrational frequencies have been assigned and compared with experimental IR and Raman spectra and they are supported each other.

Experimental and density functional theory and ab initio Hartree-Fock study on the vibrational spectra of 2-(4-fluorobenzylideneamino)-3-(4-hydroxyphenyl) propanoic acid.

2-(4-Fluorobenzylideneamino)-3-(4-hydroxyphenyl) propanoic acid (4-FT) was synthesized through the reaction of 4-fluorobenzaldehyde and l-tyrosine in refluxing EtOH. The structure of 4-FT was verified by measuring 1H NMR, FTIR and Raman. The ground-state geometries were optimized at B3LYP/6-31G**, B3LYP/6-31G*, HF/6-31G** and HF/6-31G* levels without symmetry constrains. The vibrational wavenumbers of 4-FT were calculated at same levels. The scaled spectra using B3LYP methods, which are in a good agreement with the measured spectra, are superior to those calculated using HF methods.

Bis(3,5-dimethyl-pyrazole)[N-salicyl-idene-ß-alaninato(2-)]copper(II) dihydrate.

In the title compound, [Cu(C(10)H(10)NO(3))(C(5)H(8)N(2))(2)]·2H(2)O, the Cu(II) atom is coordinated by three N atoms and two O atoms in a distorted square-pyramidal geometry. The crystal packing is stabilized by inter-molecular O-H⋯O and N-H⋯O hydrogen bonds.

Study on the oxidation form of adenine in phosphate buffer solution.

The oxidation of adenine in phosphate buffer solution is investigated using square-wave voltammetry and in situ UV spectroelectrochemistry. The geometry of adenine and the derivatives optimized at DFTB3LYP-6-31G (d, p)-PCM level is in agreement with the crystal structure, and the imitated UV spectra of adenine and the product at electrode are consistent with the in situ UV spectra. The relationship between the electrochemical property and the molecular structure is also discussed. The experimental and theoretical results show that the adenine oxidation origins from the neutral adenine.