Formation of a new layered aluminophosphate [Al3P4O16][C5N2H9]2[NH4]

A new layered aluminophosphate [Al3P4O16][C5N2H9]2[NH4] (1) has been crystallized in a gel system with molar ratio of Al(PrOi)3:3.6 H3PO4:5.9 1,2-dimethylimidazole:12 TEG:3.4 H2O at 180 °C. Its structure is solved by single-crystal X-ray diffraction analysis. Compound 1 crystallizes in the monoclinic space group P21/c (no. 14), with a = 10.402(1), b = 14.545(1), c = 16.361(1) A, β = 96.397(6)°, and Z = 4. The inorganic layers, which are constructed from alternating tetrahedral AlO4 and PO3(O) units, contain 4.6 nets and are featured by a series of ◊3(Tp)5 chains. The layers are further held together through strong H-bonds between the terminal oxygen groups and ammonium cations NH4+ as well as protonated 1,2-dimethylimidazole molecules located in the interlayer. Formation of the 4.6 nets of 1 can be thought as the condensation of ◊3(Tp)5 chains.