Theoretical insights into rolicyclidine adsorption and sensing using modified C₆₀ fullerene

1-(1-Phenylcyclohexyl) pyrrolidine (Rolicyclidine (Php)) is a potent dissociative arylcyclohexylamine with psychotropic properties, and finding methods for rapid, accurate, and facile detection of Php by traditional analytical methods remains an ongoing challenge. To address this challenge, in this study, the structural, electronic, and adsorption properties of pristine and boron- and silicon-doped C₆₀ fullerenes (BC₅₉ and SiC₅₉, respectively) were investigated using DFT theory to identify suitable candidates for Php adsorption and detection. The robustness of the predicted trends was assessed using the B97D/6-31G(d), ωB97XD/6-31G(d), and B97D/6-311G (d,p) computational levels, while selected calculated properties of pristine C₆₀ were compared with available experimental data. The calculations suggest that B and Si substitution modify the structural and electronic properties of pristine C₆₀, with Si substitution producing the largest local structural distortion. The BSSE-corrected adsorption energies indicate relatively weak-to-moderate Php adsorption on C₆₀ and BC₅₉, whereas SiC₅₉ is predicted to provide substantially stronger adsorption. At the B97D/6-31G(d) level, the corrected adsorption energies were -6.96, -8.04, and -38.79 kcal.mol^-1 for C₆₀@Php, BC₅₉@Php, and SiC₅₉@Php, respectively. The additional B97D/6-311G (d,p) calculations produced the same qualitative adsorption trend, confirming that the main conclusions are not dependent on the selected basis set. Based on this comparative theoretical screening, SiC59 may be prioritized for experimental investigation as a strong Php-adsorption material, whereas BC59 may be prioritized as a candidate sensing material because of its predicted reversibility and comparatively large adsorption-induced electronic perturbation. These assignments represent theoretical screening results and require validation through material fabrication, selectivity testing, kinetic measurements, and evaluation under realistic operating conditions.