Hydrothermal Synthesis and Structure of Fe(NH(3))(2)PO(4): A Novel Monophosphate.
ABSTRACT Fe(NH(3))(2)PO(4) is synthesized under mild hydrothermal conditions in the presence of urea. The crystal structure is solved for powder X-ray diffraction data. The unit cell is orthorhombic, a = 10.1058(2) Å, b = 6.3676(2) Å, c= 7.5714(2) Å, space group Pnma, Z = 4. The structure consists of a three-dimensional network of FeO(4)N(2) octahedra and PO(4) tetrahedra linked by vertex sharing. Two crystallographically independent ammonia molecules are linked to the iron atom. This compound is the first three-dimensional solid structurally characterized containing Fe-NH(3) bonds.
SourceAvailable from: Zakariae Amghouz[Show abstract] [Hide abstract]
ABSTRACT: Two-dimensional zinc phosphate NH4Zn2(PO4)(HPO4) (), via ammonia vapor interaction at room temperature, transforms to a one-dimensional novel compound NH4Zn(NH3)PO4 (). By ammonia desorption (in air at room temperature) transforms to NH4ZnPO4 () with a well-known ABW-zeolitic topology. The crystal structure of was solved ab initio using synchrotron powder X-ray diffraction data (monoclinic, P21/a, a = 16.5227(2) Å, b = 6.21780(8) Å, c = 5.24317(6) Å, β = 91.000(2)°, Z = 4). The structures of three compounds include extra-framework ammonium cations to the 4-fold coordinated zinc (ZnO4 tetrahedra for and , and ZnO3N tetrahedra for ) and phosphorus (PO4 tetrahedra) with bi-, mono- or three-dimensional linkages, respectively for , or . To our knowledge, the process described here constitutes the first example of dimensionality change in the solid phase promoted by a solid-gas interaction at room temperature in metal phosphates.Chemical Communications 05/2014; 50(51). DOI:10.1039/c4cc01314j · 6.72 Impact Factor
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ABSTRACT: The open-framework compounds Fe(NH3)2PO4 and Fe(NH4)(HPO4)2 were synthesized by hydrothermal reactions in the H3PO4–(NH2)2CO–FeCl3–H2O system. The electron paramagnetic resonance spectra for Fe(NH3)2PO4 show an isotropic signal with g = 2, characteristic of high spin Fe(III) ions in an octahedral environment. Below 22 K the Fe(NH3)2PO4 compound exhibits a long-range antiferromagnetic ordering in which the magnetic interactions involve Fe–O–P–O–Fe superexchange pathways. Fe(NH4)(HPO4)2 exhibits an antiferromagnetic behaviour with the presence of a significant ferromagnetic component from 18 to 3 K. In this temperature range one component of the resonance signal undergoes a shift from 336 mT (g = 2) toward magnetic fields near to zero, indicating the existence of low-dimensional ferromagnetic interactions. The presence of that ferromagnetic component was attributed to the frustration of one third of the total Fe(III) spins in the compound. Below 3 K, the effect of the long-range interactions causes an antiparallel arrangement of the magnetic moments inducing another magnetic transition to an antiferromagnetic phase.Journal of Materials Chemistry 01/2001; 11(9):2315-2319. DOI:10.1039/b104361g · 6.63 Impact Factor
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ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.ChemInform 03/2010; 31(9). DOI:10.1002/chin.200009022