title: Phenolate- and acetate (both μ2-1,1 and μ2-1,3 modes)-bridged linear Co(II)3 and Co(II)2Mn(II) trimers: magnetostructural studies.
abstract: A full report on the synthesis, crystal structure, spectroscopic characterization, and magnetic properties of two new trinuclear complexes (one homo- and another heterotrinuclear) [(L)2Co(II)3(OAc)4(MeOH)2]·6MeOH (1) and [(L)2Co(II)2Mn(II)(OAc)4(MeOH)2]·6MeOH (2) [HL = N-methyl-N-2-hydroxybenzyl-2-aminoethyl-2-pyridine] is presented. The properties of 1 and 2 are compared to that of three previously communicated complexes [(L)2Ni(II)3(OAc)4(MeOH)2]·6MeOH (3), [(L)2Ni(II)2Mn(II)(OAc)4(H2O)2] (4), and [(L)2Ni(II)2Co(II)(OAc)4(MeOH)2]·6MeOH (5) (Inorg. Chem.2007, 46, 5128-5130). All are centrosymmetric trimers with the central metal ion situated on an inversion center. Adjacent metal ions are triply bridged by a μ2-phenolate and two acetate (one in μ2-1,1 mode and another in μ2-1,3 mode) groups. Magnetic investigations reveal that the complexes are ferromagnetically coupled (J in cm(-1)): +1.20 (1) and +0.71 (2). The reported J values are +1.10 (3), -0.30 (4), and +1.06 (5). It reveals that total spins are as follows: S = 9/2 (1), 11/2 (2), 3 (3), 1/2 (4), 7/2 (5). The role of M-O(μ2-phenoxide)-M', M-O(μ2-1,1-acetate)-M', and M-O(μ2-1,3-acetate)-M' (M = M' = Co(II), Ni(II); M = Co(II), M' = Mn(II); M = Ni(II), M' = Mn(II), Co(II)) bond angles on the observed magnetic behavior has been noted.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India.
authors.forename: Anuj Kumar
authors.initials: AK
authors.lastname: Sharma
authors.forename: Francesc
authors.initials: F
authors.lastname: Lloret
authors.forename: Rabindranath
authors.initials: R
authors.lastname: Mukherjee