Catalytic, electrocatalytic and sensing roles of O–Mn+ and N–N intermolecular interactions between nitrogen oxides and dihydrazone
摘要
Stable organic molecules bearing functional groups in different chemical environments are exhibit distinct characteristics, making them essential in materials science. The exploration of novel catalysts in synthetic chemistry focuses on creating new synthetic methodologies or materials with better efficiency and sustainability. Here we report the synthesis of a dihydrazone, ((N’1E, N’2E)-N’1,N’2-bis(2-hydroxybenzylidene)oxalohydrazide) from salicylaldehyde and oxalyldihydrazide in a water-methanol medium under ambient stirring conditions. Subsequent refluxing of the prepared dihydrazone and aluminium nitrate nonahydrate (Al(NO3)3·9H2O) suspension in methanol yielded in its oxidative product salicylaldehyde azine under mild conditions. Structural characterization of both dihydrazone and azine was done by LC-MS, 1H & 13C NMR and FTIR techniques. These investigations indicate that the nitrate moiety and aluminium ion in aluminium nitrate promotes oxidation of the azomethine functionality in dihydrazone via O-Al3+ and N–N intermolecular interactions, facilitating azine formation without the need for harsh oxidants. Spectroscopic (absorption and emission (excitation at 402 nm)) and electrochemical studies of the dihydrazone were performed in the absence and presence of various metal nitrates, sodium nitrite, 2,4-dinitrotoluene and tetrabutylammonium nitrate. These experimental results demonstrate that nitrogen oxides showed catalytic, electrocatalytic and N–N intermolecular (electrostatic) interactions on dihydrazone, it is depending on strength of positive center (metal/non-metal) in analytes. The computational investigation of the dihydrazone was carried out to clarify its charge distribution, molecular stability, and chemically reactive sites.