Concentration and Temperature Effects on the Electronic Absorption Spectra of 1-pyridinyl-2-methylene-benzenecarbohydrazonic Acid Following Solvatochromic Studies

In this work, UV–Vis. electronic spectra of 1-pyridinyl-2-methylene-benzene carbohydrazonic acid (L) have been studied. The different bands observed have been assigned to the proper electronic transitions. The solvatochromic behavior of this compound is investigated by studying their electronic spectra in organic solvents with different polarities. The longer wavelength band is assigned to an intermolecular charge transfer (CT) transition. The solvated H-bonding complexes formed between dimethylformamide and L is also investigated. ΔG, and Kf values of this complex have been determined. Effects of temperature increase and concentration changes on the longer spectroscopic wavelength band of 1- pyridinyl-2-methylene-benzenecarbohydrazonic acid were studied too.