Synthesis, Characterization and Crystal Structures of new Palladium(II) Complexes and the first Platinum(III) Complex Containing ATT (ATT = 6‐Aza‐2‐thiothymine)

Treatment of the ligand 6‐aza‐2‐thiothymine (ATT, HL, 1) with palladium chloride in methanol forms the ionic complex [(HL)4Pd]Cl2·8MeOH (2), while its reaction with palladium iodide in same solvent produces the neutral complex trans‐[(HL)2PdI2]·2MeOH (3) in high yields. The reaction of 1 with Na2[PdCl4] in the presence of sodium acetate in a molar ratio of 2:1:2 and with platinum(II) chloride in presence of sodium acetate led to the dimer tetranuclear complexes [(L4Pd2)NaCl]2·8MeOH (4) and [L4Pt2Cl2]·6MeOH·H2O (5). The latter is the first PtIII complex of the ligand. All complexes were characterized by elemental analyses and IR spectroscopy and the crystal structures of 2, 3, 4 and 5 are determined by single‐crystal X‐ray diffraction. Crystal data for 2 at −80 °C: triclinic space group P 1, a = 1006.6(1), b = 1006.9(1), c = 1158.1(1) pm, α = 85.20(1)°, β = 83.84(1)°, γ = 88.91(1)°, Z = 1, R1 = 0.0278; for 3 at −80 °C: triclinic space group P 1, a = 490.5(1), b = 977.2(2), c = 1116.8(2) pm, α = 90.26(1)°, β = 102.33(1)°, γ = 96.08(1)°, Z = 1, R1 = 0.0394; for 4 at −80 °C: orthorhombic space group Ccca, a = 1791.7(2), b = 1874.1(2), c = 2044.0(1) pm, Z = 4, R1 = 0.0341 and for 5 at −80 °C: monoclinic space group P21/c, a = 1464.3(1), b = 2003.7(1), c = 1368.5(1) pm, β = 95.66(1)°, Z = 4, R1 = 0.0429.