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Synthesis, Magnetochemistry, and Spectroscopy of Heterometallic Trinuclear Basic Trifluoroacetates [Fe 2 M(μ 3 ‐O)(CF 3 COO) 6 (H 2 O) 3 ]·H 2 O (M = Mn, Co, Ni)
Author(s) -
Gavrilenko Konstantin S.,
Vértes Attila,
Vanko Gyorgy,
Kiss Laszlo F.,
Addison Anthony W.,
Weyhermüller Thomas,
Pavlishchuk Vitaly V.
Publication year - 2002
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/1099-0682(200212)2002:12<3347::aid-ejic3347>3.0.co;2-r
Subject(s) - chemistry , magnetochemistry , crystallography , octahedron , antiferromagnetism , monoclinic crystal system , metal , mössbauer spectroscopy , electron transfer , stereochemistry , crystal structure , organic chemistry , physics , condensed matter physics
Three new µ 3 ‐oxo(trifluoroacetato) complexes [Fe III 2 M II (μ 3 ‐O)(CF 3 COO) 6 (H 2 O) 3 ]·H 2 O [M = Mn ( 1 ), Co ( 2 ), Ni ( 3 )] have been prepared. Compounds 1 and 2 crystallize in the monoclinic space groups C 2/ c [ a = 22.002(5), b = 13.647(3), c = 24.767(4) Å, β = 98.23(3)°] and C 2/ m [ a = 21.426(4), b = 15.100(2), c = 14.815(3) Å, β = 117.99(2)°], respectively. The coordination spheres of the metal ions are essentially octahedral, with the Fe−O distances [1.870(5) Å] falling in the usual range for these systems. Magnetochemical studies reveal the presence of antiferromagnetic exchange in the isosceles triangular skeletons of the polynuclear species. Application of the isotropic spin Hamiltonian H = −2 J FeM [ S Fe1 S M + S M S Fe2 ] − 2 J FeFe [ S Fe1 S Fe2 ] gives the fitting parameters: g Fe = g Mn = 2.00, J Fe ‐ Fe = −56.50(7) and J Fe ‐ Mn = −16.23(4) cm −1 ( 1 ), g mol = 2.09(1), J Fe ‐ Fe = −42.8(3.5) cm −1 , J Fe ‐ Co = −17.8(1.4) cm −1 ( 2 ) and g Fe = 2.00, g Ni = 2.215(2), J Fe ‐ Fe = −45.60(1) and J Fe ‐ Ni = −16.96(2) cm −1 ( 3 ). A Mössbauer investigation confirms that no electron transfer from Mn II or Co II to Fe III occurs during the syntheses of these complexes. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)