Synthesis, characterization, structure determination from powder X-ray diffraction data, and biological activity of azo dye of 3-aminopyridine and its complexes of Ni(II) and Cu(II)

In the present work azo dye ligand of 3-aminopyridine (L) and its complexes of NiII and CuII were synthesized, characterized and evaluated for antibacterial and antifungal activities in vitro. The L ligand was synthesized by reacting diazonium ion of 3-aminopyridine with 1-naphthole in presence of sodium acetate. The ligand (L) and its complexes were characterized by elemental analysis (CHN), magnetic susceptibility, molar conductivity, UV-Vis spectra, and infrared technique. The (L) azo dye exhibited high sensing for the pH changes. The color of L dye changed from red in basic medium to yellow color in acidic medium. The data of CHN, UV-Vis and magnetic susceptibility indicate that the complexes [Ni(L)2Cl2] and [Cu(L)2Cl2] are tetrahedral. The complexes of Ni(II) and Cu(II) exhibited potent activity against growth of Staphylococcus aureus and Escherichia Coli as well as against Penicillium Sp. And Aspergillus niger. Under visible irradiation (395 nm), the (L) azo dye of pyridine exhibited a significant change in the spectra under irradiation. KEY WORDS: Pyridine, Photoisomerization, Pyridylazo, Biological activity, pH sensor Bull. Chem. Soc. Ethiop. 2020, 34(3), 523-532. DOI: https://dx.doi.org/10.4314/bcse.v34i3.8

Physico-chemical properties of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) diazonium ion: a theoretical investigation

NNKDI TCTT molecular orbital energies (a), molecular orbitals 46 (HOMO), 47 (LUMO) and 48 (LUMO+1) as calculated at the B3LYP/6-311G** level of theory.

Determination of paracetamol in pharmaceutical samples by spectrophotometric method

It is described the use of 1,3 dinitrobenzene or 2,4 dinitrophenyl hydrazine is used as coupling agent for the spectrophotometric determination of paracetamol. This method is easy and simple based on the reaction of acid hydrolysis of paracetamol to produce p-aminophenol, which in turn reacts with nitrite in acidic standard to form diazonium ion, which is coupled with coupling agent in basic standard to produce azo dyes. The formed dyes follow Beer’s law in the range of 0.8-20.5 mg mL-1 of paracetamol with 1, 3 dinitrobenzene or 0.5-18.4 mg mL-1 of paracetamol with 2,4 dinitrophenyl hydrazine with absorption maxima at 429 nm or 430 nm. The molar absorptivity and Sandell’s sensitivity of paracetamol with 1,3 dinitrobenzene or paracetamol with 2,4 dinitrophenyl hydrazine azo dyes were 1.965×104 L mol-1 cm-1 or 2.776×104 L mol-1 cm-1, and 7.692×10-3 mg cm-2 or 5.698×10-3 mg cm-3 respectively. The dyes formed are stable for more than 12 h. The optimal reaction circumstances and other analytical parameters are evaluated. Interference due to foreign organic compounds have been studied. The method has been effectively applied to the determination of paracetamol in pharmaceutical samples.

Robust non-covalent and covalent anchored N,N,N′,N’-tetramethyl-p-phenylenediamine derivative on electrode surface via spontaneous physical immobilization and in situ generated aryldiazonium ion electro-grafting: implication for on-surface chemistry and electro-catalytic determinations

Redox active electrodes were fabricated via robust adsorption and electro-grafting of an electroactive diazonium ion. The electrodes have implications in post-functionalization as well as electro-catalytic activity.