E-catalog        

Библиогр.: 9 назв.

A model fulvic acid (FA) was synthesized from a natural dye, hematoxylin, in a slow oxidative polymerization/condensation reaction catalysed by OH− at pH ca. 12. The resulting dark-brown product, acidified to pH ca. 2, did not precipitate from the reaction solution. It was isolated and purified by cation-exchange resin. Its physicochemical and spectroscopic properties, as determined by means of elemental analysis, molecular weight analyses, Fourier transform infra red (FTIR) and ultraviolet–visible (UV–VIS) spectroscopy, X-ray diffraction and electron paramagnetic resonance (EPR) spectroscopy, showed a close resemblance to natural FA. The similarity and differences between synthetic fulvic acids derived from hematoxylin and the natural fulvic acids substances are discussed. Quantum-chemical calculations of the supposed primary oxidation products of hematoxylin are performed and compared with observations.