Assembly of Helical Hydrogen Bonds in a New Layered Aluminophosphate [C6N3H17][Al2(HPO4)(PO4)2]

A new layered aluminophosphate, [C6N3H17][Al2(HPO4)(PO4)2] (denoted AlPO-CJ21), has been prepared in an alcoholic system by the use of N-(2-aminoethyl)-piperazine (AEPP) as the template. Its inorganic layer containing a series of bridged six-membered rings (MRs) is a new type of 4.6-net sheet built up from AlO4, PO2(OH)(=O), and PO3(=O) tetrahedra. Interestingly, inorganic helical chains of right- or left-handedness are presented in the aluminophosphate layers, and fascinating hydrogen-bonded helices are self-assembled under solvothermal conditions between organic templates and inorganic sheets via strong hydrogen bondings of O···N atoms. Crystal data: monoclinic, P21 (No. 4), a = 10.069(2) (angstrom), b = 8.0875(16) (angstrom), c = 10.598(2) (angstrom), (beta)= 94.71(3)°, z = 2, R1 = 0.0325 [I > 2(sigma)(I)], and wR2 = 0.0807 (all data); Flack parameter: 0.03.