Systematic quantum chemical tailoring to the molecular structure, optical and nonlinear optical properties of N/B dopped C60 buckminsterfullerene

Buckminsterfullerene is hard to study experimentally and computationally owing to its unique reactivity and larger molecular size, respectively. The whole C60 fullerene molecule consists of two types of chemical bonds i.e. hexagon-hexagon bonds and hexagon-pentagon bonds. A series of heterofullerenes (C58hhBN-C58hpBN) was designed by substitution in C60 fullerene with nitrogen (N) and boron (B) at the hexagon-hexagon bond and hexagon-pentagon bond positions. Quantum chemical methods were employed to examine the structural and optoelectronic characteristics of the designed compounds as compared to parent C60. The average polarizability measurements shown that the linear response of the C58hpBB compound (αiso = 116.7 × 10−24 esu, αaniso = 10.56 × 10−24 esu) is dominant. Among all designed compounds, a change in hexagon-pentagon bonds is seen as more effective for tuning the NLO response properties. For instance, C58hpBB and C58hpNN showed the larger <γ> response of 164.5 × 10−36 and 172.5 × 10−36 esu indicating greater potential for NLO materials. A number of techniques such as natural bond orbitals (NBOs), molecular electrostatic potential (MEPs), frontier molecular orbitals (FMOs) and absorption spectra were used to investigate the optoelectronic properties. The maximum absorption of molecules are found in between 569 and 800 nm. According to FMO analysis, C58hpBB and C58hpNN have smaller energy gaps (0.97 eV and 1.47 eV) and better intramolecular charge transfer. The current study evokes the aspect of hexagon-hexagon bond and hexagon-pentagon bond modification for efficient dopped buckminsterfullerene.