A new kinetic spectrophotometic method for the determination of trace amount manganese(II) in Tea real samples has been described based on it s the catalytic effect on the oxidations of 1 - (2 – Pyridyl Azo) - 2 - Naphthol, (PAN), by potassium bromated in sulfuric acid. The reaction is followed spectrophotometrically by measuring the decrease in the absorbance at 547.5 nm. Under the optimum con...

peptide synthesis. Enzymatic peptide synthesis is more advantageous than chemical synthesis since the enzymatic method is stereoselective and is secure from racemization. There are, however, several problems to be solved with this method. Secondary hydrolysis of the resulting peptide may arise from the inherent nature of the protease. Moreover, the method is limited to the use of amino acid der...

This work addresses the possibilities of using synthesized novel magnesium complex dyes in zinc pigmented organic coatings based on epoxyester resin to reduce content these while maintaining or increasing anticorrosive efficiency them. The complexes Mg-Dye-I (C34H26MgN8O6), Mg-Dye-II (C26H19MgN3O5), Mg-Dye-III (C17H10MgN2O3), and Mg-Dye-IV (C25H18MgN4O6) with a series azo carboxylate ligands we...

In this paper, the strength and kinetics of two charge-transfer complexes, naphthol-methylviologen and pyrene-methylviologen, are studied using dynamic force spectroscopy. The dissociation rates indicate an enhanced stability of the pyrene-methylviologen complex, which agrees with its higher thermodynamic stability compared to naphthol-methylviologen complex.

The title compound, C(29)H(30)N(2)O(4), adopts a distorted Z configuration with respect to the oxime group, which is almost coplanar with the adjacent naphthalene ring [dihedral angle = 4.11 (2)°]. There is one half-mol-ecule in the asymmetric unit, with a crystallographic twofold rotation axis passing through the central C atom of the -CH=N-O-(CH)(5)-O-N=CH- bridge. Within the mol-ecule, the d...

The mol-ecule of the title compound, C(27)H(26)N(2)O(4), lies across a crystallographic inversion centre and adopts an l-shaped configuration. Within the mol-ecule, the two naphthalene units are approximately perpendicular, making a dihedral angle of 80.24 (5)°. The two intramolecular O-H⋯N hydrogen bonds, generate S(6) ring motifs. In the crystal structure, every mol-ecule links five other mol...

Nonadiabatic electronic transitions between potential energy surfaces play a dominant role in many photoinduced chemical reactions, such as charge transfer, branching pathways in dissociation, and cis/trans isomerizations. Furthermore, nonadiabatic internal conversion (IC) to the ground state (S0) is believed to protect photoexcited natural chromophores (e.g. nucleic acid bases of DNA.) against...

The title Schiff base compound, C(18)H(14)N(2)O(3), has an inter-mediate state between NH and OH tautomers. The mol-ecular structure is stabilized by an O-H⋯N hydrogen bond. The dihedral angle between the naphthalene ring system and the benzene ring is 37.44 (5)°.

The mol-ecule of the title compound, C(31)H(34)N(2)O(4), adopts an L-shaped configuration, in which the naphthalene units are approximately perpendicular, making a dihedral angle of 87.89 (3)°. Intramolecular H-bonds are formed between the OH substituents and the N atoms at each end of the molecule. In the crystal structure, each mol-ecule links six other mol-ecules into an infinite three-dimen...