Formation of helix-containing rods in a hybrid inorganic–organic material

Abstract

The novel aluminum ethylenediphosphonate fluoride, [HN(CH 2CH 2NH 3) 3][Al 2(O 3PCH 2CH 2PO 3) 2F 2]·H 2O ( 1) (monoclinic, P2 1 /n, a=12.145(4) Å, b=9.265(3) Å, c=20.422(6) Å, β=104.952(4)°, Z=3, R 1=0.092, wR 2=0.196) has been synthesized by solvothermal methods in the presence of tris(2-aminoethyl)amine and its structure determined using single microcrystal X-ray diffraction data. Compound 1 is a one-dimensional extended chain structure composed of well-separated anionic [Al 2(O 3PCH 2CH 2PO 3) 2F 2] 4− rods containing helical chains of corner-shared cis-AlO 4F 2 octahedra at their core. The charge-compensating tris(2-aminoethyl)ammonium cations separate the anionic [Al 2(O 3PCH 2CH 2PO 3) 2F 2] 4− rods that contain either left- or right-handed helical chains. The incorporation of the organic components into this hybrid material has aided the adoption of one-dimensionality by the compound and defined the pitch of the helical AlO 4F chain.