Ab initio calculations of supramolecular complexes of fullerene C60 with CdTe and CdS

This paper presents the results of ab initio quantum-chemical calculations of supramolecular complexes C₆₀CdHal, C₆₀]₄CdHal, and C₆₀]₆CdHal (Hal = S, Te), which simulate the defects forming in fullerite during the absorption or adsorption of cadmium telluride (sulfide). Calculations of the electronic structure of complexes with inclusion of their relaxation to the equilibrium state have been performed in terms of the density functional theory with the B3LYP hybrid functional. The obtained enthalpies of formation of complexes show that their formation leads to the energy gain of the order of 0.5–1.5 eV depending on the complex type. It has been shown that the formation of tetrahedral complexes C₆₀]₄CdTe with the intercalated CdTe molecule is possible only with a considerable distortion of the tetrahedral void. The energy spectrum of low-lying excited electron states for the linear and octahedral complexes has been calculated. It has been found that a decrease in symmetry with the formation of complexes leads to the appearance of excited states of allowed singlet transitions in the electron spectrum, which are forbidden in optical spectra of initial components.