Abstract

Two novel aluminophosphites, [NH₂(CH₂)₆NH₂][Al(OH)(H(HPO₃))₂] and [Al(OH)(H(HPO₃))₂]·2H₂O (denoted as NKX-1 and NKX-4, respectively), with a molar ratio P∶Al = 2, have been synthesized for the first time using a hydrothermal technique. Single crystals of these compounds have also been prepared. Structure refinement from single crystal X-ray diffraction data shows NKX-1 with composition [NH₂(CH₂)₆NH₂][Al(OH)(H(HPO₃))₂] crystallizes in the monolinic space group C2/c, with a = 29.123(17) Å, b = 6.772(4) Å, c = 6.851(4) Å, V = 1349.3(14) ų, Z = 4, and NKX-4 with composition [Al(OH)(H(HPO₃))₂]·2H₂O crystallizes in the orthorhombic space group Cmma, with a = 6.949(2) Å, b = 17.398(6) Å and c = 7.903(3) Å, V = 955.4(6) ų, Z = 4. Both compounds contain AlO₆ octahedra and HPO₂ (OH) tetrahedra in their structure. Each AlO₆ octahedron shares two hydroxide group corners with two adjacent AlO₆ octahedra to form infinite Al–O–Al chains.