Characteristic of peroxyoxalate-chemiluminescence intensity in the presence of Chlorpheniramine maleate and its analytical application

It has been shown that Chlorpheniramine maleate (CPM) increases chemiluminescence intensity of bis-(2,4,6-trichlorophenyl)oxalate (TCPO) with hydrogen peroxide in the presence of biphenylquinoxaline as a fluorophore. In this work, the effect of CPM on the intensity of chemiluminescence (CL) in the system of (TCPO-sodium salicylate-fluorophore-hydrogen peroxide) was investigated. The fall and rise rates constants were also studied. A pooled-intermediate model was used for determining the kinetics parameters of CL with and without CPM. Results indicated that addition of CMP to this system increases the fall rate constant and decreases the rise rate constant. Results also specified that there is a linear relationship between CPA concentration and chemiluminescence intensity in the range 0.66-21.5 μg/ml. Detection limit 0.18 μg/ml and the relative standard deviation (RSD) <7% was obtained. This work is introduced as a new method for the determination of CMP.     

Structural and nonlinear optical properties of cross‐conjugated system benzophenone thiosemicarbazone: a vibrational spectroscopic study

The nonlinear optical (NLO) compound of interest benzophenone thiosemicarbazone (BTSC) was grown and the molecular structure generated with the aid of density functional theory (DFT). FT‐Raman and IR spectra were recorded and analyzed. The harmonic wavenumbers and IR and Raman intensities were computed with the B3LYP method. The observed vibrational wavenumbers were compared with the calculated results. The assignments of the experimental spectra were made with the help of normal coordinate analysis (NCA) following the scaled quantum mechanical force field (SQMFF) methodology. The electronic structure of the most important molecular fragments is described in terms of natural bond orbital (NBO) analysis. Copyright © 2010 John Wiley & Sons, Ltd.     

Comparative study of electronic structure and optical properties of a series of Pt(II) complexes containing different electron‐donating and ‐withdrawing groups: a DFT study

We report a quantum‐chemistry study of electronic structures and spectral properties of a series of Pt(II) complexes containing different substituents (? CH₃ ( 1 ), ? OCH₃ ( 2 ), ? NO₂ ( 3 ), ? CF₃ ( 4 ), and ? COOH ( 5 )). 1 and 2 have been previously synthesized in experiment, while 3 – 5 are artificial complexes that we suggest can be used to investigate the electron‐withdrawing effect on charge injection, transport, absorption, and phosphorescence properties. The results reveal that the stronger electron‐donating and ‐withdrawing groups show stronger absorption intensity, while the phosphorescence efficiency is generally higher for complexes containing electron‐donating substituents. 1 and 2 are easier for hole injection, while 3 – 5 are easier for electron injection. The enhanced electron injection abilities of 3 – 5 will confine more excitons in the light‐emitting layer (EML) and may not result in lower electroluminescence (EL) efficiency than 1 and 2 . These results suggest that the three artificial complexes may be new emitters in organic light‐emitting diodes (OLEDs). Copyright © 2009 John Wiley & Sons, Ltd.