A new 3methyl1phenyl4arylazo5pyrazolone and 1, 3diphenyl4arylazo5pyrazolone have been synthesized and characterized by elemental analysis, IR, mass and 1H NMR spectra. The acid dissociation constants (pKa values) of t...A new 3methyl1phenyl4arylazo5pyrazolone and 1, 3diphenyl4arylazo5pyrazolone have been synthesized and characterized by elemental analysis, IR, mass and 1H NMR spectra. The acid dissociation constants (pKa values) of the investigated ligands were determined potentiometrically and spectrophotometrically. The stability constants of the transition metal ions (VO2+, Cr3+, Mn2+, Co2+, Ni2+, Cu2+ and Zn2+) with the investigated ligands were determined potentiometrically at different ionic strengths (0.167, 0.1, 0.05 and 0.025 M) NaCl at 25oC and different temperature (25, 30, 35, and 45oC). The values of stability constants were found to decrease with increasing ionic strengths and temperature. The stoichiometries were studied using spectrophotometric and conductimetric methods, the results indicate the existence of 1:1 and 1:2 (M:L) metal:ligand species. The relationships between the stability constants of the complexes, ionization constants of the ligands have been discussed and correlated. The thermodynamic parameters (?G, ?H and ?S) and the thermodynamic stability constants for all of the investigated complexes were determined potentiometrically.展开更多
By the indirect action of ionizing radiation in living bodies, oxygen free radicals as OH and O, can be brought about, giving rise to the damage of biomacromolecules. It is requisite to consider whether or not the cha...By the indirect action of ionizing radiation in living bodies, oxygen free radicals as OH and O, can be brought about, giving rise to the damage of biomacromolecules. It is requisite to consider whether or not the change of copper-zinc superoxide dismutase展开更多
The resonance-enhanced multiphoton ionization (REMPI) spectrum of NO has been obtained. The spectral lines can be attributed to NO D2∑←X2П transitions. NO molecules are ionized via the resonant intermediate D2∑ st...The resonance-enhanced multiphoton ionization (REMPI) spectrum of NO has been obtained. The spectral lines can be attributed to NO D2∑←X2П transitions. NO molecules are ionized via the resonant intermediate D2∑ states and by (3+2) REMPI process.展开更多
文摘A new 3methyl1phenyl4arylazo5pyrazolone and 1, 3diphenyl4arylazo5pyrazolone have been synthesized and characterized by elemental analysis, IR, mass and 1H NMR spectra. The acid dissociation constants (pKa values) of the investigated ligands were determined potentiometrically and spectrophotometrically. The stability constants of the transition metal ions (VO2+, Cr3+, Mn2+, Co2+, Ni2+, Cu2+ and Zn2+) with the investigated ligands were determined potentiometrically at different ionic strengths (0.167, 0.1, 0.05 and 0.025 M) NaCl at 25oC and different temperature (25, 30, 35, and 45oC). The values of stability constants were found to decrease with increasing ionic strengths and temperature. The stoichiometries were studied using spectrophotometric and conductimetric methods, the results indicate the existence of 1:1 and 1:2 (M:L) metal:ligand species. The relationships between the stability constants of the complexes, ionization constants of the ligands have been discussed and correlated. The thermodynamic parameters (?G, ?H and ?S) and the thermodynamic stability constants for all of the investigated complexes were determined potentiometrically.
基金Project supported by the National Natural Science Foundation of China.
文摘By the indirect action of ionizing radiation in living bodies, oxygen free radicals as OH and O, can be brought about, giving rise to the damage of biomacromolecules. It is requisite to consider whether or not the change of copper-zinc superoxide dismutase
文摘The resonance-enhanced multiphoton ionization (REMPI) spectrum of NO has been obtained. The spectral lines can be attributed to NO D2∑←X2П transitions. NO molecules are ionized via the resonant intermediate D2∑ states and by (3+2) REMPI process.
