Methanetrisamidines HC[C(NR)NHR]3} (R = i-Pr 1a; Ph 1b) were reacted with different metal complexes. Reaction of 1a with NiCl2(H2O)6 occurred with protonation of 1a and formation of [C(C(NHi-Pr)2)3]2+[NiCl4]2−} 2, whereas the reaction with CuCl gave [C(C(N(i-Pr)CuCl)NHi-Pr)2(C(NHi-Pr)2)] 3. The formation of 2 and 3, which contain the N–H tautomeric form of 1a, occurred with H-migration from carbon