Vertical electronic excitation energies for singlet states have been computed for the high energy density material TdN4 in order to assess synthetic routes that originate from excited states of N-2 molecules. Based on linear response coupled-cluster calculations, the lowest six excited states are 9.35(1 T-1(1)), 10.01(1 T-1(2)), 10.04(1 (1)A(2)), 10.07(1 E-1), 10.12(2 T-1(1)), and 10.42(2 T-1(2)) eV above the ground state. Comparison with the energies of excited states of N-2 + N-2 fragments, leads us to propose that the most likely synthetic route for TdN4 involving this mechanism arises from combination of two bound quintet states of N-2.