Tuning Fe-Se Tetrahedral Frameworks by a Combination of [Fe(en)] Cations and Cl Anions.

A one-dimensional (1D) chain compound ( = ethylenediamine), featuring tetrahedral FeSe chains separated by [Fe(en)] cations and Cl anions, has been synthesized by a low temperature solvothermal method using simple starting materials. The degree of distortion in the Fe-Se backbone is similar to previously reported compounds with isolated 1D FeSe chains. Fe Mössbauer spectroscopy reveals the mixed-valent nature of [Fe(en)](FeSe)Cl with Fe centers in the [FeSe] chains and Fe centers in the [Fe(en)] complexes.

Synthesis, Crystal Structure, and Magnetic Properties of RMgSiPn (R = La, Ce; Pn = P, As).

Four new quaternary pnictides, RMgSiPn (R = La, Ce; Pn = P, As), were synthesized via high-temperature solid-state reactions and gas-phase transport reactions with iodine. Their crystal structures were determined by single crystal X-ray diffraction. All four compounds are isostructural and crystallize in a new structure type in the orthorhombic space group Pnma (No.

High surface area and Z' in a thermally stable 8-fold polycatenated hydrogen-bonded framework.

1,3,5-Tris(4-carboxyphenyl)benzene assembles into an intricate 8-fold polycatenated assembly of (6,3) hexagonal nets formed through hydrogen bonds and π-stacking. One polymorph features 56 independent molecules in the asymmetric unit, the largest Z' reported to date. The framework is permanently porous, with a BET surface area of 1095 m(2) g(-1) and readily adsorbs N2, H2 and CO2.

Control over connectivity and magnetism of tetrahedral FeSe2 chains through coordination Fe-amine complexes.

The synthesis and structural characterization is reported for [Fe(dien)2][FeSe2]2 and [Fe(tren)][FeSe2]2, two new mixed-valence compounds that contain infinite ∞(1)(FeSe2) tetrahedral chains separated by Fe-amine complexes. The inter- and intra-chain magnetic interactions can be controlled by changing the denticity of the amine while preserving the general structural motif.

NH4FeCl2(HCOO): synthesis, structure, and magnetism of a novel low-dimensional magnetic material.

Solvothermal synthesis was used to create a low-dimensional iron(II) chloride formate compound, NH4FeCl2(HCOO), that exhibits interesting magnetic properties. NH4FeCl2(HCOO) crystallizes in the monoclinic space group C2/c (No. 15) with a = 7.

Chemical excision of tetrahedral FeSe(2) chains from the superconductor FeSe: synthesis, crystal structure, and magnetism of Fe(3)Se(4)(en)(2).

Fragments of the superconducting FeSe layer, FeSe2 tetrahedral chains, were stabilized in the crystal structure of a new mixed-valent compound Fe3Se4(en)2 (en = ethylenediamine) synthesized from elemental Fe and Se. The FeSe2 chains are separated from each other by means of Fe(en)2 linkers. Mössbauer spectroscopy and magnetometry reveal strong magnetic interactions within the FeSe2 chains which result in antiferromagnetic ordering below 170 K.