Structures and thermodynamic properties of amido and imido monomer and oligomer compounds as potential single-source precursors for group 14 nitrides have been obtained at the B3LYP/DZP level of theory. The thermodynamic analysis shows that Cl3MNH2 amido compounds are stable with respect to both HCl elimination and oligomerization processes. In contrast, Cl2MNH and ClMN species should undergo oligomerization. Formation of trimer compounds is more exothermic compared to the corresponding dimers. The M(IV) and M(II) cubanes are found to be the most promising precursors for group 14 nitrides: the ammonolysis reaction of cubanes is thermodynamically allowed in a wide temperature range for all M.