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Open framework materials such as zeolites and metalorganic frameworks are garnering tremendous interest because of their intriguing architecture and attractive functionalities. Thus, new types of open framework materials are highly sought after. Here, we present the discovery of completely new inorganic framework materials, where, in contrast to conventional inorganic open frameworks, the scaffold is not based on tetrahedral EO4 (E = main group element) but octahedral MO6 (M = transition metal) building blocks. These structural features place them closer to polyoxometalates than zeolites. The first representatives of this class of materials are [(R)24(NH4)14(PO(OH)2)6]·[M134(PO3(OH,F))96F120] (M = Co, R = C2Py = 1-ethylpyridinium and M = Ni, R = C4C1Py = 1-butyl-3-methylpyridinium) featuring interlinked fullerene-like nanosphere cavities. Having a transition metal building up the framework brings about interesting properties, for example, spin-glass behavior, and, with this particular topology, a hedgehog-like spin orientation.

A set of different open framework iron phosphates have been synthesized ionothermally using a task-specific ionic liquid, 1-butyl-4-methylpyridinium hexafluorophosphate, that acts in the synthesis as the reaction medium and mineralizer: (NH4)(2)Fe-2(HPO4)(PO4)Cl2F (1) and K2Fe2(HPO4(PO4)Cl2F (2) exhibit similar composition and closely related structural features. Both structures consist of {Fe-2(HPO4)(PO4)-Cl2F}(2)- macroanions and charge balancing ammonium or potassium cations. Their open framework structure contains layers and chains of corner-linked {Fe(1)O2Cl4} and {Fe(2)F2O4} octahedra, respectively, interconnected by PO4 tetrahedra forming 10-ring channels. KFe(PO3F)F-2 (3) is built up by {Fe[(PO3F)(4/3)F-2/2]}{Fe(PO3F)(2/3) F2/2F2} layers separated by K+ cations. Chains of alternating {FeF2O4} and {FeO2F4} octahedra, which are linear for 1 but undulated for 2, are linked to each other via corner-sharing {PO3F} tetrahedra with the fluorine pointing into the interlayer space. The compounds were characterized by means of single crystal and powder X-ray diffraction, infrared spectroscopy, and magnetic measurements. 1 reveals a strong ground state spin anisotropy with a spin 5/2 state and a magnetic moment of 5.3 mu(B) /Fe3+. Specific heat and magnetic data unveil three magnetic transitions at 95, 50, and 3.6 K. Compound 2 has a very similar crystal structure as compared to 1 but exhibits a different magnetic behavior: a slightly lower magnetic moment of 4.7 mu(B)/Fe3+ and a magnetic transition to a canted antiferromagnetic state below 90 K. Compound 3 exhibits typical paramagnetic behavior close to room-temperature (5.71 mu(B)/Fe3+). There are no clear indications for a phase transition down to 2 K despite strong antiferromagnetic spin-spin interactions; only a magnetic anomaly appears at 50 K in the zero-field cooled data.

An ionothermal synthesis study of transition metal phosphates using the ionic liquid 1-butyl-4-methylpyridinium hexafluorophosphate [C(4)mpy] [PF6] yielded four new, different open framework manganese compounds, that is, K2Mn3 (HPO4)(2)(PO3F)F-2 (1), (NH4)(2)Mn-3 (HPO4)(2) (PO3F)-F-2 (2), KMn3 (H2PO4)(HPO4)(2)F-2 (3), and (NH4)Mn-3(H2PO4)(PO3F)(2)F-2 (4). The obtained products not only feature new framework topologies unprecedented in the family of phosphates but also interesting properties as the transition metal gives rise to both luminescent (rendering them potential nonrare earth containing red emitting phosphors) and unconventional magnetic properties governed by geometric frustrations. Aside from the structural analysis (powder and single-crystal X-ray diffraction, infrared spectroscopy), a variety of characterization methods (photoluminescence spectroscopy and magnetic measurements) were applied to study the material's properties. Single crystal X-ray studies reveal that 1 (P2(1)/c with a = 5.501(1), b = 14.203(3), c = 16.905(4) angstrom, beta = 108.65(3)degrees, V = 1251.4 angstrom(3), and Z = 4) and 2 (P2(1)/c with a = 5.587(1), b = 14.507(3), c = 17.364(3) angstrom, beta = 108.75(3)degrees, V = 1332.6(5) angstrom(3), and Z = 4) feature S-shaped 18-ring channels along [100], which are formed by trimer-Mn3O9F2 chains parallel to [100] and interconnecting PO3 (OH) and PO3F tetrahedra. The structure of compounds 3 (C2/c with a = 20.307(4), b = 7.635(1), c = 7.834(2) angstrom, beta = 103.26(3)degrees, V = 1182.2(4) angstrom(3), and Z = 4) and 4 (C2/c with a = 20.402(4), b = 7.673(1), c = 7.845(2) angstrom, beta = 103.56(3)degrees, V = 1193.8(4) angstrom(3), and Z = 4) are characterized by layers, which are built of Mn3O8F4 octahedra trimers, with Kagome topology parallel to the be plane featuring 3,6-ring channels. The layers are stacked according to a sequence of AA(i) along the a axis. Taking into account the [P(2)O-3(OH)/P(2)O3F] tetrahedra, the Kagome layer