We analysed the photooxidation reaction in the electro-(1O2) and nucleophilic (O2•−) reaction of 2-pyridone azo derivatives. First, we calculated the energy (enthalpies) of tautomers formation, which is a measure of d...We analysed the photooxidation reaction in the electro-(1O2) and nucleophilic (O2•−) reaction of 2-pyridone azo derivatives. First, we calculated the energy (enthalpies) of tautomers formation, which is a measure of durability and the probability of their formation. We performed the light fastness calculations of the monoazopyridone dyes. Using the semi-empirical methods of quantum chemistry AM1 and PM3, the reactivity indicators of superdelocalisability (SrE(N)) and the electron density distribution in ground state on the highest occupied HOMO orbital and the lowest unoccupied excited state LUMO in 2-pyridone phenylazo derivatives were calculated. Superdelocalisability coefficients enable the stability to oxidising agents of various chemical molecules depending on the tautomeric forms in which they may occur. The results of the electron density calculations at the HOMO and LUMO boundary orbitals allow to determine the tendency to electrophilic attack with singlet oxygen 1O2 or nucleophilic attack of the superoxide anion O2•−on a specific atom in the molecule. The structure of the dyes was optimised with MM+, MD and AM1 or PM3 until a constant energy value was achieved with a convergence criterion of 0.01 kcal/mol.展开更多
1 Results We have recently reported the successful use of some new ionophores in construction of PVC-based membrane selective sensors for Fe3+,Ni2+,Co2+,Hg2+ and Cd2+ ions by some Schiff base ligands. Schiff bases are...1 Results We have recently reported the successful use of some new ionophores in construction of PVC-based membrane selective sensors for Fe3+,Ni2+,Co2+,Hg2+ and Cd2+ ions by some Schiff base ligands. Schiff bases are one of the most important classes of ligand in coordination chemistry. In this work we reported the optimized structures of four tetra dentate mono azo Schiff base compounds.Using AM1,PM3 and MNDO semi-empirical methods for the optimization of the compounds,then we compared all of theoreti...展开更多
文摘We analysed the photooxidation reaction in the electro-(1O2) and nucleophilic (O2•−) reaction of 2-pyridone azo derivatives. First, we calculated the energy (enthalpies) of tautomers formation, which is a measure of durability and the probability of their formation. We performed the light fastness calculations of the monoazopyridone dyes. Using the semi-empirical methods of quantum chemistry AM1 and PM3, the reactivity indicators of superdelocalisability (SrE(N)) and the electron density distribution in ground state on the highest occupied HOMO orbital and the lowest unoccupied excited state LUMO in 2-pyridone phenylazo derivatives were calculated. Superdelocalisability coefficients enable the stability to oxidising agents of various chemical molecules depending on the tautomeric forms in which they may occur. The results of the electron density calculations at the HOMO and LUMO boundary orbitals allow to determine the tendency to electrophilic attack with singlet oxygen 1O2 or nucleophilic attack of the superoxide anion O2•−on a specific atom in the molecule. The structure of the dyes was optimised with MM+, MD and AM1 or PM3 until a constant energy value was achieved with a convergence criterion of 0.01 kcal/mol.
文摘1 Results We have recently reported the successful use of some new ionophores in construction of PVC-based membrane selective sensors for Fe3+,Ni2+,Co2+,Hg2+ and Cd2+ ions by some Schiff base ligands. Schiff bases are one of the most important classes of ligand in coordination chemistry. In this work we reported the optimized structures of four tetra dentate mono azo Schiff base compounds.Using AM1,PM3 and MNDO semi-empirical methods for the optimization of the compounds,then we compared all of theoreti...
