Flux synthesis of two new open-framework zinc phosphites with 16-ring channels

Two new three-dimensional open-framework zinc phosphites, (H2aep)2·Zn6(HPO3)8 (1) and H3taea·Zn3(HPO3)4.5 (2) have been synthesized by the H3PO3 flux method, where aep = 1-(2-aminoethyl)piperazine and taea = tris(2-aminoethyl)amine. Compound 1 has a 3,4-connected framework with (4,6,8) sheets connected by corner-sharing 4-ring chains. Compound 2 has 3-connected sheets built from quintuple-fused 4-rings, which are further linked by HPO3 units to form the three-dimensional structure. The presence of large 16-ring channels in the two structures is noteworthy. Crystal data: 1, monoclinic, P21/c, a = 18.8613(7) Å, b = 9.0856(5) Å, c = 24.9485(8) Å, β = 107.211(6)°, V = 4083.9(3) Å3, Z = 4, R1 = 0.0457, wR2 = 0.1050; 2, monoclinic, C2/c, a = 28.911(2) Å, b = 8.302(3) Å, c = 19.513(3) Å, β = 103.715(16)°, V = 4549.8(17) Å3, Z = 4, R1 = 0.0428, wR2 = 0.1165.