Two new cyano-bridged heterobinuclear complexes, [Mn(II)(phen)2Cl][Fe(III)(bpb)(CN)2] x 0.5CH3CH2OH x 1.5H2O (1) and [Mn(II)(phen)2Cl][Cr(III)(bpb)(CN)2] x 2H2O (2) [phen = 1,10-phenanthroline; bpb(2-) = 1,2-bis(pyridine-2-carboxamido)benzenate], and four novel azido-bridged Mn(II) dimeric complexes, [Mn2(phen)4(mu(1,1)-N3)2][M(III)(bpb)(CN)2]2 x H2O [M = Fe (3), Cr (4), Co (5)] and [Mn2(phen)4(mu(1,3)-N3)(N3)2]BPh4 x 0.5H2O (6), have been synthesized and characterized by single-crystal X-ray diffraction analysis and magnetic studies. Complexes 1 and 2 comprise [Mn(phen)2Cl]+ and [M(bpb)(CN)2]- units connected by one cyano ligand of [M(bpb)(CN)2]-. Complexes 3-5 are doubly end-on (EO) azido-bridged Mn(II) binuclear complexes with two [M(bpb)(CN)2]- molecules acting as charge-compensating anions. However, the Mn(II) ions in complex 6 are linked by a single end-to-end (EE) azido bridging ligand with one large free BPh4(-) group as the charge-balancing anion. The magnetic coupling between Mn(II) and Fe(III) or Cr(III) in complexes 1 and 2 was found to be antiferromagnetic with J(MnFe) = -2.68(3) cm(-1) and J(MnCr) = -4.55(1) cm(-1) on the basis of the Hamiltonian H = -JS(Mn)S(M) (M = Fe or Cr). The magnetic interactions between two Mn(II) ions in 3-5 are ferromagnetic in nature with the magnetic coupling constants of 1.15(3), 1.05(2), and 1.27(2) cm(-1) (H = -JS(Mn1)S(Mn2)), respectively. The single EE azido-bridged dimeric complex 6 manifests antiferromagnetic interaction with J = -2.29(4) cm(-1) (H = -JS(Mn1)S(Mn2)). Magneto-structural correlationship on the EO azido-bridged Mn(II) dimers has been investigated.
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http://dx.doi.org/10.1021/ic050181b | DOI Listing |
Dalton Trans
June 2019
Department of Chemistry, University College of Science, University of Calcutta, 92, A. P. C. Road, Kolkata 700009, India.
Reaction of Mn(ii) salts with a flexidentate Mannich base ligand, N,N'-dimethyl-N,N'-bis(2-hydroxy-3-methoxy-5-methylbenzyl)ethylenediamine (H2L) in the presence of chloride or azide ions yielded two new tetranuclear complexes, [Mn4L2(μ3-Cl)2Cl2] (1) and [Mn4L2(μ1,1,1-N3)2(N3)2] (2). Single crystal X-ray structural analyses reveal that these two discrete tetranuclear Mn(ii) complexes possess defective dicubane cores with two μ3-Cl (for 1) or two μ1,1,1-N3 bridges (for 2). One of the triply bridging groups is situated above and the other one below the plane of the four Mn(ii) ions.
View Article and Find Full Text PDFDalton Trans
November 2015
Institut für Physikalische and Theoretische Chemie, Technische Universität Graz, Stremayrgasse 9, A-8010 Graz, Austria.
The syntheses and structural characterization of three new monodimensional azido-bridged manganese(ii) complexes with empirical formulae [Mn(N3)2(aminopyz)2]n (1), [Mn(N3)2(4-azpy)2]n (2) and [Mn(N3)2(4-Bzpy)2]n (3) (pyz = pyrazine (1,4-diazine)), 4-azpy = 4-azidopyridine and 4-Bzpy = 4-benzoylpyridine) are reported. 1 is a monodimensional compound with double EO azido bridges, 2 is an alternating monodimensional compound with double end-on and double end-to-end azido bridges in the sequence di-EO-di-EE and 3 is a monodimensional compound with double end-on and double end-to-end azido bridges in the sequence di-EO-di-EO-diEO-di-EO-di-EE. The magnetic properties of 1-3 are reported.
View Article and Find Full Text PDFInorg Chem
November 2005
Coordination Chemistry Institute, State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, PR China.
One-dimensional chiral copper(II) and manganese(II) coordination polymers with single asymmetric end-to-end (EE) azide bridges, [Cu(R-L)2(N3)]n(ClO4)n (1), [Cu(S-L)2 (N3)]n(ClO4)n (2), [Mn(R-L)2(N3)]n(ClO4)n (3), and [Mn(S-L)2(N3)]n(ClO4)n (4) (R-L or S-L = R- or S-pyridine-2-carbaldehyde-imine), have been synthesized, using azide ions as bridging groups and chiral Schiff bases as auxiliary ligands, and characterized. The crystal structure determination of complexes 1 and 2 reveals the formation of one-dimensional chiral chains, in which the central Cu(II) ion is six-coordinate in the form of an elongated octahedron. Complex 3 consists of chiral helical polymeric chains, in which the central Mn(II) has a slightly distorted octahedral geometry.
View Article and Find Full Text PDFInorg Chem
November 2005
Shanghai Key Lab of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, Shanghai 200062, China.
Four new inorganic-organic hybrid coordination polymers in which 1D or 2D manganese(II) azido inorganic motifs are interlinked into higher-dimensional networks have been synthesized by use of a series of bis(pyridyl)-type organic bridging ligands (linkers) with different side groups and/or different coordination orientations. The dimensionality and the topology of the manganese(II) azido motif and the whole structure are sensitive to the organic linkers used. Compounds 1 and 3 are 3D coordination polymers with pillared-layer architectures: in 1, 2D Mn(II) layers with alternate double end-on (EO) and single end-to-end (EE) azido bridges are pillared by zigzag organic linkers, and 3 is built from single EE azido-bridged Mn(II) layers and linear organic linkers.
View Article and Find Full Text PDFInorg Chem
June 2005
Department of Chemistry, Tsinghua University, Beijing 100084, PR China.
Two new cyano-bridged heterobinuclear complexes, [Mn(II)(phen)2Cl][Fe(III)(bpb)(CN)2] x 0.5CH3CH2OH x 1.5H2O (1) and [Mn(II)(phen)2Cl][Cr(III)(bpb)(CN)2] x 2H2O (2) [phen = 1,10-phenanthroline; bpb(2-) = 1,2-bis(pyridine-2-carboxamido)benzenate], and four novel azido-bridged Mn(II) dimeric complexes, [Mn2(phen)4(mu(1,1)-N3)2][M(III)(bpb)(CN)2]2 x H2O [M = Fe (3), Cr (4), Co (5)] and [Mn2(phen)4(mu(1,3)-N3)(N3)2]BPh4 x 0.
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