In addition to the known adducts of the C 60 with 3,6-diaryl-1,2,4,5-tetrazines, in the present work some other 3,6-disubstituted tetrazines of variable electron withdrawing and donating character were studied theoretically. Here the molecular structure and electronic properties were predicted for –CH 3 , –NH 2 , –Ph, –NO 2 , and –CN substituted tetrazines. The reaction energies were calculated for molecules with different functional groups and found to be in the range of −1.26 to −2.17eV. Based on the results the relative magnitude order follows: –NO 2 >–CN>–H>–CH 3 >–NH 2 >–Ph, suggesting that the reaction energy is increased by increasing the electron withdrawing character of the functional groups. Unlike traditional behavior of C 60 as an electron-deficient dienophile in Diels–Alder reactions, it has been predicted that in the studied reactions it can act as an electron rich agent. The HOMO/LUMO energy gap of the C 60 can be decreased by the chemical modification with the tetrazine containing –NH 2 . Also, the field emission from the C 60 may be facilitated upon the adsorption of tetrazines with electron donating groups of –CH 3 , –NH 2 , and –Ph.