An open-framework zincophosphate, [C4N3H16][Zn4.5(PO4)4] 1, has been hydro- thermally synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in the tetragonal space group P 4 with a = 14.512(5), c = 8.914(3), V = 1877.3(11)3, C4H16N3O16P4Zn4.50, Mr = 780.24, Z = 4, Dc = 2.761 g/cm3, μ = 6.103 mm-1, F(000) = 1536, T = 298(2) K, R = 0.0416 and wR = 0.0816. In the structure, ZnO4 and PO4 tetrahedra are linked to each other, forming four-membered rings which are connected variably to form two secondary building units (SBUs). The SBUs are connected so as to generate two chains along the c axis, which are further linked together alternatively via common oxygen atoms (Zn-O-P) giving rise to 8-ring-channels in the [001] direction, and the protonated guest diethylenetriamine (DETA) molecules sit in the middle of these channels. Other characterizations are also described by elemental analysis, thermal analysis and IR and fluorescent spectra. An open-framework zincophosphate, [C4N3H16] [Zn4.5 (PO4) 4] 1, has been hydro- configured and characterized by single-crystal X-ray diffraction. It crystallizes in the tetragonal space group P4 with a = 14.512 (5), c = 8.914 (3) , V = 1877.3 (11) 3, C4H16N3O16P4Zn4.50, Mr = 780.24, Z = 4, Dc = 2.761 g / cm3, μ = 6.103 mm-1, F ) = 1536, T = 298 (2) K, R = 0.0416 and wR = 0.0816. In the structure, ZnO4 and PO4 tetrahedra are linked to each other, forming four-membered rings which are connected variably to form two secondary building units ( SBUs are connected so as to generate two chains along the c axis, which are further linked or via common oxygen atoms (Zn-OP) given rise to 8-ring-channels in the [001] direction, and the protonated guest diethylenetriamine (DETA) molecules sit in the middle of these channels. Other characterizations are also described by elemental analysis, thermal analysis and IR and fluorescent spectra.