Ga4(PO4)4F•N2C7H11•1/2H2O:: A three-dimensional open framework with 12-membered pores and "bowl-shaped" building units

Ga-4(PO4)(4)F .N2C7H11.1/2H(2)O was prepared solvothermally in pure form using 4-(dimethyl-amino)pyridine (4-DMAP) as a template in various solvents (pyridine, pyridine/water, and ethylene glycol) within a broad reaction temperature range (115-180 degreesC). Its structure was determined from X-ray single-crystal diffraction data at low temperature (-105 degreesC). Ga-4-(PO4)(4)F .N2C7H11.1/2H(2)O crystallizes in the monoclinic space group C2/c, witll a = 22.093(4) Angstrom, b = 13.904(2) Angstrom, c = 14.230(2) Angstrom, beta = 98.431.(3)degrees, V = 4324 Angstrom (3), and Z = 8. Its three-dimensional framework is composed of novel distorted "bowl-shaped" octameric double 4-ring units, which are built up by corner-sharing PO4 and GaO4 tetrahedra and GaO4F trigonal bipyramids. The structure consists of a pseudohexagonal array of cylindrical 12-membered pores running parallel to the c axis hosting the protonated 4-DMAP molecules. These pores are interconnected along the b axis through double 3-ring windows. The framework remains stable up to 300 degreesC under oxygen.