The features of the solvatochromic effects of absorption (Ab) and photoluminescence (PL) spectra, as well as the quantum yield of emission (QYE) of carbon nanoparticles (CNPs) synthesized by various methods from a mixture of citric acid and nitrogen-containing precursors, in protic and aprotic solvents have been studied. It has been shown that the parameters of the spectra Ab, PL and the QYE value of particle solutions to a large extent depend on the method, conditions and modes of synthesis, the method of modification and separation of CNPs, the types and composition of precursors, and also the fundamental properties and pH of solvents. In solvents with a dielectric constant of 4.5 – 109.5, the QYE value of particles varies in a wide range from 10.8 to 100.0 %, and the PL band peak shifts from 466.4 to 536.8 nm. The presence of strong solvatochromic effects in the spectra of Ab and PL particles was shown, and the important role of the processes of protonation and deprotonation of surface groups of CNPs was established. The influence of universal and specific interactions on the spectroscopic parameters of CNPs has been investigated, and a significant contribution to the solvatochromic effects of specific interactions has been demonstrated.
