Hydrothermal synthesis and intercalation behavior of a layered titanium phosphate Ti₂(H₂PO₄)(HPO₄)(PO ₄)₂ • 0.5C₆N₂H₁₆, with an extended γ-phase intercalated into organic amine

The structure exhibits an extended γ-phase intercalated into organic amine, but the interaction behavior presented unusual features because of the presence of N,N′-dimethylpiperazine cations between the layers. With a hydrothermal technique, a layered titanium phosphate with the formula Ti ₂(H₂PO₄)(HPO₄)(PO₄) ₂ • 0.5C₆N₂H₁₆ (denoted TP-J2) has been prepared by treating the Ti/H₃PO₄/H ₂O/1-methylpiperazine system directly. The as-synthesized products were characterized by powder X-ray diffraction, CP-MAS solid-state ³¹P NMR spectroscopy, thermogravimetric and differential thermal analyses (TG-DTA). The structure was solved by single-crystal X-ray diffraction analysis and it presents an extended γ-phase intercalated with organic amine. Crystal data: triclinic, P1̄, a = 8.106 (2) Å, b = 8.197 (2) Å, c = 11.658 (2) Å. α = 78.32 (3)°, β = 80.85 (3)°, γ = 77.90 (3)°, Z = 2. Additionally, the intercalation behavior of TP-J2 with n-alkyl monoamine (n = 2, 3, 4, 6, 8, 10 and 12) was investigated. Owing to the strong brønsted base, N,N′- dimethylpiperazine, resides in the interlayer, it presented unusual features of TP-J2 in contrast with that of γ-Tip.