SYNTHESIS OF 2,4-DINITROPHENYLHYDRAZONE FULLERENE C<sub>60</sub>
In the present work, 2,4-dinitrophenylhydrazone of fullerene C<sub>60</sub> was obtained in the condensation reaction of the oxopiperazine monoadduct of fullerene C<sub>60</sub> with 2,4-dinitrophenylhydrazine for the first time. The initial oxopiperazine adduct of C<sub>60</sub> fullerene was previously obtained in the sonochemical reaction of C<sub>60</sub> fullerene with 2-oxopiperazine. The condensation reaction of the oxopiperazine adduct of fullerene C<sub>60</sub> 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 C<sub>60</sub> 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 C<sub>60</sub> with a yield of 92% was isolated from the reaction solution by column chromatography. The resulting compound is soluble in DMSO, DMF, CHCl<sub>3</sub>, poorly soluble in ethanol and insoluble in water. The resulting compound was characterized using one- and two-dimensional NMR <sup>1</sup>H, <sup>13</sup>C (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 C<sub>60</sub> 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<sup>-6</sup> mol/L.