Theoretical studies on one-dimensional polymers constructed from BN-substituted C36 fullerene

We have performed comparative DFT calculations to devise some possible one-dimensional (1D) polymers constructed from BN-substituted fullerenes, C24B6N6 as well as C12B12N12, and their parent C-36 with the face-to-face linking model. Binding energies for the (C24B6N6)(n) compounds with n > 2 and (C12B12N12)(n) compounds with n >= 5 are found to be always larger than those of their corresponding (C-36)n ones, which indicates that the BN-substituted models of the C-36 polymers are more stable than their carbon counterparts investigated in this study. Our results also indicate that band gaps decrease with an increase in the number of the C24B6N6 cages such that E-g of these compounds decrease from 1.185 eV for C24B6N6 to 0.245 eV for (C24B6N6)(7) while an increasing trend is observed for Eg values of the (C12B12N12)(n) polymers and Eg increases from 2.035 eV for C12B12N12 to 2.779 eV for (C12B12N12)(7). All of the (C24B6N6)(n) and (C12B12N12)(n) are found to be semiconductors with larger Eg as compared to the (C-36)(n) polymers while (C-36)(n) with n >= 4 are metallic.