Hydrothermal syntheses, characterizations of novel three-dimensional indium phosphite and indium phosphite–phosphate with intersecting 8-membered ring channels: [In3(H2PO3)3(HPO3)4]·(trans-C6N2H16) and [In6(HPO3)8(H2PO3)5(H2PO4)]·(C3N2H12)2

Two new three-dimensional indium phosphite and indium phosphite–phosphate [In3(H2PO3)3(HPO3)4]·(trans-C6N2H16) 1 and [In6(HPO3)8(H2PO3)5(H2PO4)]·(C3N2H12)22 have been synthesized under hydrothermal conditions using 1,2-diaminocyclohexane (1,2-DACH) and 1,3-diaminopropane (1,3-DAP) as structure directing agents, respectively and further characterized by powder X-ray diffraction, single crystal X-ray diffraction, IR spectroscopy, TGA, ICP-AES and elemental analyses. These two compounds have the similar 3D inorganic framework structures with intersecting 8-membered ring (8-MR) channels. In compound 1, the diprotonated trans-1,2-DACH cations occupy the 8-MR channels along the [0 0 1] direction even though a mix of trans- and cis-isomers of 1,2-DACH molecules are added in the reaction mixture. Moreover, the chirality of trans-1,2-DACH alternates along the channels. It is noted that compound 2 is the first indium phosphite–phosphate compound. Crystal data: compound 1, monoclinic, C2/c (No. 15), a = 18.675(4) Å, b = 10.220(2) Å, c = 13.419(3) Å, β = 98.29(3)°, V = 2534.4(9) Å3, and Z = 4. Compound 2, orthorhombic, Pna21 (No. 33), a = 26.7974(9) Å, b = 9.8459(3) Å, c = 18.5441(6) Å, V = 4892.8(3) Å3, and Z = 4.