Coexistence of major and minor tautomers of 1-methylcytosine (1-MeC) in a single metal complex, trans-Pt(1-MeC-N3)(1-MeC-N4)X2 (X=Cl, I): metal migration N3→N4 at acidic pH

Although differing in relative abundance by an estimated factor of 104–105, the major amino tautomer of 1-methylcytosine (C) and the rare imino tautomer form (C*) can be found simultaneously bonded to a PtII center.