The solution-mediated syntheses and single crystal structures of (N2C6H14) . Zn(HPO4)(2) . H-2 (I), H3N(CH2)(3)NH3 . Zn-2(HPO4)(3) (II), and (N2C6H14) . Zn-3(HPO4)(4) (III) are described. These phases contain vertex-sharing ZnO4 and HPO4 tetrahedra, accompanied by doubly protonated organic cations. Despite their formal chemical relationship, as members of the series of t . Zn-n(HPO4)(n+1) (t = template, n 1-3), these phases adopt fundamentally different crystal structures, as one-dimensional, two-dimensional, and three-dimensional ZnO4/HPO4 networks, for I, II, and III, respectively. Similarities and differences to some other zinc phosphates are briefly discussed. Crystal data: (N2C6H14) . Zn(HPO4)(2) H2O, M-r= 389.54, monoclinic, space group P2(1)/n (No. 14), a 9.864(4) Angstrom, b = 8.679(4)Angstrom, c 15.780(3)Angstrom, beta=106.86(2)degrees, V=1294.2(8) Angstrom(3), z=4, R(F) = 4.58%, R-w(F) = 5.28% [1055 reflections with I>3 sigma(I)]. H3N(CH2)(3)NH3 . Zn-2(HPO4)(3), M-r = 494.84, monoclinic, space group P2(1)/c (No. 14), a=8.593(2)Angstrom, b=9.602(2) Angstrom, c = 17.001(3) Angstrom, beta = 93.571(8)degrees, V= 1400.0(5) Angstrom(3), Z= 4, R(F) = 4.09%, Rw(F)=4.81% [2794 reflections with I>3 sigma(I)]. (N2C6H14) . Zn-3(HPO4)(4), M-r = 694.25, monoclinic, space group P2(1)/n (No. 14), a = 9.535(2) Angstrom, b = 23.246(4) Angstrom, c = 9.587(2) Angstrom, beta=117.74(2)degrees, V=1880.8(8) Angstrom(3), z=4, R(E)=3.23%, R-w(F) =3.89% [4255 reflections with I>3 sigma(I)]. (C) 1999 Academic Press.