Here we report that attempted preparation of low-valent Ca-I complexes in the form of LCa-CaL (where L is a bulky beta-diketiminate ligand) under dinitrogen (N-2) atmosphere led to isolation of LCa(N-2)CaL, which was characterized crystallographically. The N-2(2-) anion in this complex reacted in most cases as a very potent two-electron donor. Therefore, LCa(N-2)CaL acts as a synthon for the low-valent Ca-I complex LCa-CaL, which was the target of our studies. The N-2(2-) anion could also be protonated to diazene ( N2H2) that disproportionated to hydrazine and N-2. The role of Ca d orbitals for N-2 activation is discussed.