K3[C3N3(COO)3]·2H2O – Crystal Structure of a New Alkali Derivative of the Multidentate Ligand Triazine Tricarboxylate

Potassium‐1,3,5‐triazine‐2,4,6‐tricarboxylate dihydrate K₃[C₃N₃(COO)₃] · 2H₂O was obtained by saponification of the respective ethyl ester in aqueous solution under mild conditions and subsequent crystallization at 4 °C. The crystal structure of the molecular salt was elucidated by single‐crystal X‐ray diffraction [P , a = 696.63(14), b = 1748.5(3), c = 1756.0(3) pm, α = 119.73(3), β = 91.96(3), γ = 93.84(3)°, V = 1847.6(6) · 10⁶ pm³, Z = 6, T = 200 K]. Perpendicular to [100] the triazine tricarboxylate and potassium ions are arranged in layers alternating with layers of crystal water molecules. Two thirds of the triazine tricarboxylate units form hexagonal channels being filled with the remaining triazine tricarboxylate molecules. K₃[C₃N₃(COO)₃] · 2H₂O was additionally investigated by means of FTIR spectroscopy, TG and DTA measurements.