Synthesis, characterization and molecular structure of a new tetrameric palladium(II) complex containing schiff-bases derived from AMTTO (AMTTO = 4-amino-6-methyl-1,2,4-triazine-thione-5-one)

The reactions of AMTTO = 4-amino-6-methyl-1,2,4-triazine-thione-5-one (AMTTO, 1) with 2-hydroxybenzaldehyde (salicylaldehyde) and 4- hydroxybenzaldehyde in methanol under reflux conditions led to the corresponding Schiff-bases (H₂L1 and H₂L2). The reaction of H ₂L1 with palladium acetate in ethanol and additional recrystallization from toluene gave the tetrameric complex [Pd(L)] ₄·2C₇H8 (2). All compounds were characterized by infrared spectroscopy, elemental analyses as well as by X-ray diffraction studies. Crystal data for H₂L1 at -80°C: space group P2 ₁/c with a = 1285.4(1), b = 707.7(1), c = 1348.2(1) pm, β = 109.32(1)°, Z = 4, R₁ = 0.0328, H₂L2 at -80°C: space group P4₃2₁2 with a = 762.5(1), b = 762.5(1), c = 4038.9(2) pm, Z = 8, R₁ = 0.025 and for 2 at -103°C: space group C2/c with a = 2862.5(6), b = 2847.6(6), c = 1727.8(4) pm, β = 105.18(3)°, Z = 8, R₁ = 0.0704.