Synthesis of open-framework iron phosphates, [C5N2H14]2[Fe2IIIF 2(HPO4)4]·2H2O and [C5N2H14][Fe4III(H2O)4F2(PO4)4], with one- and three-dimensional structures

The hydrothermal syntheses and structures of two new open-framework iron phosphates, [C5N2H14]2[Fe III 2F2(HPO4)4] ·2H2O, I, and [C5N2H14] [FeIII 4(H2O)4F2(PO 4)4], II, are presented. While the structure of I consist of FeO4F2 octahedra and HPO4 terahedra linked to form one-dimensional structure, that of II consist of FeO4(H 2O)2, FeO4(H2O)F, FeO 4F2 and PO4 units connected to give rise to a three-dimensional structure. The structure of I resembles the naturally occurring mineral tancoite while II resembles the iron phosphate, ULM-12, [C6N2H14][Fe4(PO4) 2F2(H2O)3]. Magnetic susceptibility studies indicate anti-ferromagnetic behavior in both the compounds with T N=200 and 175K for I and II, respectively. Crystal data: I, monoclinic, space group=P21/n (no. 14). a=7.2261(6), b=16.5731(14), c=11.0847(10)Ã?, β=97.265(2)°, V=1316.8(2)Ã?3, Z=4, Ï?calc=1.952gcm-1, μ(MoKα)=1. 446mm-1, R1=0.0448 and wR2=0.1141 for 1882 data [I>2Ï?(I)]; for II, monoclinic, space group=P21/n (no. 14). a=9.9691(3), b=12.4013(3), c=17.3410(3)Ã?, β=103.762(1)°, V=2082.32(9)Ã?3, Z=4, Ï?calc=2.576gcm -1, μ(MoKα)=3.162mm-1, R 1=0.0510 and wR2=0.1064 for 2979 data [I>2Ï?(I)]. © 2003 Elsevier Inc. All rights reserved