SYNTHESIS OF 2,4-DINITROPHENYLHYDRAZONE FULLERENE C<sub>60</sub>
In the present work, 2,4-dinitrophenylhydrazone of fullerene C60 was obtained in the condensation reaction of the oxopiperazine monoadduct of fullerene C60 with 2,4-dinitrophenylhydrazine for the first time. The initial oxopiperazine adduct of C60 fullerene was previously obtained in the sonochemical reaction of C60 fullerene with 2-oxopiperazine. The condensation reaction of the oxopiperazine adduct of fullerene C60 with 2,4-dinitrophenylhydrazine in toluene was carried out in the presence of mineral acids (hydrochloric or polyphosphoric acid) at 60° C during 1 hour. Mineral acids are required for the activation of the carbonyl group of the oxopiperazine monoadduct of C60 fullerene, i.e. they are process catalysts. The use of acetic acid as a catalyst did not provide the desired result. The reaction product 2,4-dinitrophenylhydrazone of fullerene C60 with a yield of 92% was isolated from the reaction solution by column chromatography. The resulting compound is soluble in DMSO, DMF, CHCl3, poorly soluble in ethanol and insoluble in water. The resulting compound was characterized using one- and two-dimensional NMR 1H, 13C (COZY, HSQC, HMBС), IR, UV-visible spectroscopy. The composition of the obtained compound was confirmed by elemental analysis. A photometric form of 2,4-dinitrophenylhydrazone of fullerene C60 was obtained in an alkaline medium, which is formed as a result of isomerization of the benzene ring to the quinoid form and has absorption maxima at 230, 280 and 470 nm. The calorimetric method with 2,4-dinitrophenylhydrazine is used in analytical chemistry to identify carbonyl compounds with a concentration of up to 10-6 mol/L.