title: Synthesis, structure, and magnetic properties of (A)[FeIII(oxalate)Cl2] (A = alkyl ammonium cations) with anionic 1D [FeIII(oxalate)Cl2]- chains.
abstract: The use of alkyl ammonium cations resulted in four compounds of (A)[FeIII(ox)Cl2] (A = Et3NH+ (1a, 1b), Me4N+ (2), and n-Bu4N+ (3); ox = oxalate), whose structures and magnetic properties were characterized. In all cases, the metal Fe(III) ions are six-coordinated by four oxygen atoms from two bischelating oxalate ligands and the two terminal Cl- ions in the cis position. Thus they form similar anionic 1D [FeIII(ox)Cl2]- chains. The chains are separated by alkyl ammonium cations in the lattice, and the cation size seems to control the interchain separation and packing patterns in the solid. A parallel arrangement of the [FeIII(ox)Cl2]- chains is observed for 1a, 2, and 3, while a crossed one is observed for 1b, which is a polymorph of 1a. Magnetic studies reveal the antiferromagnetic intrachain interactions in all compounds. The last three compounds, 1b, 2, and 3, show spin canting below 14.5, 9.5, and 3.8 K, respectively. The dipolar interaction over the interchain distance is proposed to be the result of 3D magnetic ordering in the materials.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China.
authors.forename: Hong-Bin
authors.initials: HB
authors.lastname: Xu
authors.forename: Zhe-Ming
authors.initials: ZM
authors.lastname: Wang
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.forename: Song
authors.initials: S
authors.lastname: Gao
mesh_terms: D000838:Anions / Q000737:chemistry; D002412:Cations / Q000737:chemistry; D002713:Chlorine / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005290:Ferric Compounds / Q000138:chemical synthesis / Q000737:chemistry; D008280:Magnetics; D008958:Models, Molecular; D010070:Oxalates / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared / Q000379:methods; D013696:Temperature
chemical_list: D000838:Anions; D002412:Cations; D005290:Ferric Compounds; D010070:Oxalates; D000644:Quaternary Ammonium Compounds; D002713:Chlorine