Synthesis of Open-Framework Iron Phosphates, [C6N2H14][FeIII2F2(HPO4)2(H2PO4)2]·2H2O and [C6N2H14]2[FeIII3(OH)F3(PO4)(HPO4)2]2·H2O, with One- and Three-Dimensional Structures

Abstract

The hydrothermal syntheses and structures of two new open-framework iron phosphates, I, [C6N2H14][FeIII2F2(HPO4)2 (H2PO4)2].2H2O, II, and [C6N2H14]2[FeIII3(OH)F3(PO4) (HPO4)2]2. H2O, are presented. The structures of both I and II consist of FeO4F2 octahedra and PO4 terahedra linked to form one- and three-dimensional structures. Both the compounds possess infinite one-dimensional chains of Fe–O/F–Fe formed by the FeO4F2 octahedra. The di-protonated DABCO cations are located in between the chains in I and within the channels in II. Whilst I possess the tancoite structure with a new chain composition, II has a three-dimensional structure similar to the gallophosphate, ULM-1. Crystal data for I: M=685.84, monoclinic, space group=C2/c (no. 15), a=7.232(2), b=20.520(7), c=13.933(4) Å, β=97.68(3)°, ν=2049.1(1) Å3, Z=4, ρcalc.=2.223 g cm−3, μ(MoKα)=1.841 mm−1, R1=0.06, wR2=0.12, S=1.17 for 163 parameters; II, M=1303.33, monoclinic, space group =C2/c (no. 15), a=18.1836(2), b=10.0126(7), c=20.0589(4) Å, β=106.08(3)°, ν=3509.0(2) Å3, Z=4, ρcalc=2.467 g cm−3, μ(MoKα)=2.830 mm−1, R1=0.034, wR2=0.081, S=1.06 for 284 parameters.