(C{sub 2}N{sub 2}H{sub 10})[Fe {sub x}V{sub 1-x}(HPO{sub 3})F{sub 3}] (x = 0.44, 0.72): Two new organically templated phosphites

Journal Article · Thu Oct 12 04:00:00 EDT 2006 · Materials Research Bulletin

DOI:https://doi.org/10.1016/j.materresbull.2006.03.014· OSTI ID:20891928

Cisneros, Jose L ^[1]; Fernandez-Armas, Sergio ^[1]; Mesa, Jose L ^[1]; Pizarro, Jose L ^[2]; Arriortua, Maria I ^[2]; Rojo, Teofilo ^[1]

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1. Departamento de Quimica Inorganica, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Apdo. 644, E-48080 Bilbao (Spain)
2. Departamento de Mineralogia y Petrologia, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco, Apdo. 644, E-48080 Bilbao (Spain)

(C{sub 2}N{sub 2}H{sub 10})[Fe {sub x}V{sub 1-x}(HPO{sub 3})F{sub 3}] (x = 0.44, 0.72) have been synthesized using mild solvothermal conditions under autogenous pressure and the ethylenediamine molecule as templating agent. The crystal structures have been determined from X-ray single-crystal diffraction data. The compounds crystallize in the orthorhombic P2{sub 1}2{sub 1}2{sub 1} space group with Z = 4 and unit-cell parameters a = 12.8494(9), b = 9.5430(6), c = 6.4372(5) A, and a = 12.8578(1), b = 9.5342(1), c = 6.4370(7) A for (C{sub 2}N{sub 2}H{sub 10})[Fe{sub 0.44}V{sub 0.56}(HPO{sub 3})F{sub 3}] and (C{sub 2}N{sub 2}H{sub 10})[Fe{sub 0.72}V{sub 0.28}(HPO{sub 3})F{sub 3}] (1) and (2), respectively. These isostructural compounds exhibit a monodimensional crystal structure formed by pillared double anionic chains with the formula [M(HPO{sub 3})F{sub 3}]{sup 2-}, extended along the [0 0 1] direction. These doubled ionic chains are the result of the linking of two simple chains in which there are alternating octahedral [MO{sub 3}F{sub 3}] and tetrahedral groups [HPO{sub 3}]. The ethylendiammonium cations are placed in the space delimited by three different chains. The metallic ions are interconnected by the pseudo-pyramidal (HPO{sub 3}){sup 2-} phosphite oxoanions, adopting a slightly distorted octahedral geometry. The IR spectra show bands corresponding to the phosphite oxoanion and the ethylendiamonium cation at 2400 and 1600 cm{sup -1}, respectively. The thermogravimetric analyses show that these phases are stable up to ca. 280 deg. C, at higher temperatures, the decomposition of the crystal structure begins by calcination of the organic cation and the elimination of the fluoride anions. The diffuse reflectance spectra show bands of the V{sup 3+} ion (d{sup 2}) in octahedral symmetry. The values of the Dq (1540, 1540 cm{sup -1}), and Racah parameters, B (560, 535 cm{sup -1}) and C (3055, 3140 cm{sup -1}) for (1) and (2), respectively, correspond with those usually found for octahedrically coordinated V(III) compounds. Magnetic measurements, performed on a powered sample from 5.0 to 300 K at 1000 G, in the ZFC and FC modes, indicate the existence of antiferromagnetic interactions.

• OSTI ID: 20891928
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 10 Vol. 41; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANTIFERROMAGNETISM
CALCINATION
CHEMICAL PREPARATION
FLUORIDES
INFRARED SPECTRA
MAGNETIC MATERIALS
MONOCRYSTALS
ORTHORHOMBIC LATTICES
PHOSPHATES
PHOSPHOROUS ACID
SPACE GROUPS
SYMMETRY
THERMAL GRAVIMETRIC ANALYSIS
VANADIUM IONS
X-RAY DIFFRACTION