Background and Objectives: The object of this study is the fullerene compound C_60/70, which is a mixture of 86% C₆₀ and 14% C₇₀ fullerenes – the most common product of graphite arc-discharge evaporation. The compound was stabilized in two different crystalline matrices: heptane (a linear alkane without π-electrons) and toluene (an aromatic solvent with a π-electron subsystem). The study focuses on the fluorescence spectra of this compound in the long-wavelength visible range (650–682 nm), where the edge of optical absorption is located and low-intensity features are observed. The aim of this work is to investigate the influence of the crystalline matrix on the fluorescence spectrum of the C_60/70 compound, to compare the spectral features observed in heptane and toluene matrices, and to explain the observed differences from the perspective of intermolecular interactions between the matrix and the embedded fullerene molecules. A further goal is to identify stable spectral lines that can be attributed to singlet-singlet electronic transitions and to assess the possibility of controlled modification of the electronic structure of polyatomic molecules by varying the matrix environment. Materials and Methods: Solutions of the C_60/70 compound in heptane and toluene were prepared at concentrations ranging from 10^–4 to 10^–8 mol/L. The samples were rapidly frozen at liquid nitrogen temperature (77.3 K) to obtain quasi-linear Shpol’skii-type spectra. Excitation was performed using a semiconductor laser with a wavelength of 365 nm, which provides sufficient energy for re-emission in the visible range. Fluorescence spectra were recorded using an ISP-51 spectrograph equipped with a high-sensitivity TCD1304DG CCD linear array, offering a pixel resolution of 0.08 nm/pixel. The obtained data were processed using specialized software (Registration No. 2017616306) designed for automation of spectral analysis. The studied spectral range was divided into two subranges: 650–661 and 673–682 nm. Results: It has been found that both matrices produce a structured fluorescence spectrum with several characteristic lines in the 650–682 nm range. The most informative spectra have been obtained at concentrations of 10^–5–10^–6 mol/L. Three stable lines near 678.09, 676.65 and 674.25 nm are present in both matrices at all concentrations and are attributed to singlet-singlet electronic transitions in fullerene molecules. The energy differences between these lines are 0.003 eV and 0.01 eV, suggesting two spectral multiplets. In the toluene matrix, additional lines at 680.50 nm and 680.14 nm appear at concentrations of 10^–5 and 10^–6 mol/L. These lines are reproducible, do not belong to pure toluene, and are not thermal noise. Their origin is discussed in terms of: (i) a larger number of nonequivalent positions for fullerene molecules in the less symmetric toluene crystal lattice; (ii) the presence of π-electron subsystems in both toluene and fullerenes, which enhances intermolecular interactions and may give rise to exciton or excimer effects; (iii) the structural diversity of C₆₀ and C₇₀ molecules, which exhibit different polarizability and ability to integrate into the matrix lattice. The intensity of the lines increases with concentration, following the laws of spectral analysis. In the heptane matrix, redistribution of excited electrons is concentrated mainly between the 678.5 nm and 676.5 nm lines, whereas in toluene a broader distribution is observed. The Stokes shift for analogous lines is slightly larger in toluene, indicating stronger interaction with the matrix. The results have demonstrated that the number of resolvable spectral lines is directly determined by the properties of the matrix media, opening prospects for controlled modification of the electronic structure of polyatomic molecules.