In:
Acta Crystallographica Section B Structural Science, International Union of Crystallography (IUCr), Vol. 62, No. 2 ( 2006-04-01), p. 245-254
Abstract:
Two isostructural metal organic framework (MOF) structures have been synthesized by solvothermal methods and examined by single-crystal X-ray diffraction. A microcrystal of 2C 4 H 12 N + [Co 3 (C 8 H 4 O 4 ) 4 ] 2− ·3C 5 H 11 NO (1) was investigated at T = 120 K using synchrotron radiation. 2C 4 H 12 N + [Zn 3 (C 8 H 4 O 4 ) 4 ] 2− ·3C 5 H 11 NO (2) was investigated at multiple temperatures ( T = 30, 100, 200 and 300 K) on a conventional diffractometer. The thermal expansion of the structure of (2) is anisotropic and along the a axis, which corresponds to the metal chain direction. The structures contain anionic frameworks with cations and solvent molecules trapped in the voids. The magnetic susceptibility ( χ ) and heat capacity ( C p ) have been measured from 1.8 to 350 K. Compound (1) orders ferromagnetically with a broad phase transition observed in C p at ∼ 6 K. The magnetic moment reaches a value of 3 µ B per Co at 2 K in a magnetic field of 9 T, and a Curie–Weiss fit to χ ( T ) gives an effective moment ( μ eff ) of 4.2 μ B and a Weiss temperature (θ) of 23 K. The exchange mechanism for the magnetic coupling is suggested to involve the Co—O—Co bridges in the individual three-metal-atom subchains. The three-dimensional magnetism presumably is due to super-exchange through two out of the three unique C 8 H 4 O 4 linker molecules, which have the carboxylate and benzene π systems well aligned.
Type of Medium:
Online Resource
ISSN:
0108-7681
DOI:
10.1107/S0108768105042795
DOI:
10.1107/S0108768105042795/lc5040sup1.cif
DOI:
10.1107/S0108768105042795/lc5040cobdcdef_120Ksup2.fcf
DOI:
10.1107/S0108768105042795/lc5040znbdcdef_30Ksup3.fcf
DOI:
10.1107/S0108768105042795/lc5040znbdcdef_100ksup4.fcf
DOI:
10.1107/S0108768105042795/lc5040znbdcdef_200Ksup5.fcf
DOI:
10.1107/S0108768105042795/lc5040znbdcdef_300Ksup6.fcf
Language:
Unknown
Publisher:
International Union of Crystallography (IUCr)
Publication Date:
2006
detail.hit.zdb_id:
2020841-8
SSG:
13
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