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Christian Nather - One of the best experts on this subject based on the ideXlab platform.
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synthesis crystal structures and investigations on the dehydration reaction of the new coordination polymers poly diaqua μ2 squarato o o μ2 4 4 bipyridine n n me ii hydrate me co ni fe
Journal of Solid State Chemistry, 2003Co-Authors: Jan Greve, Inke Jes, Christian NatherAbstract:Abstract The three new isostructural coordination polymers poly[diaqua-(μ2-squarato-O,O′)-(μ2-4,4′-bipyridine-N,N′)Me(II)] hydrate (Me=Fe, Co, Ni) were prepared by hydrothermal reaction. All Compounds are isostructural and crystallize in the monoclinic space group P21/c with 4 formula units in the unit cell (a=18.893 (1) A, b=11.450 (1) A, c=8.0985 (4) A, β=93.032 (5)°, V=1749.5 (2) A3, [Fe(C4O4)(C10H8)(H2O)2]·(H2O)3; a=18.937 (1) A, b=11.342 (1) A, c=8.0545 (5) A, β=91.83 (1)°, V=1725.3 (2) A3, [Co(C4O4)(C10H8)(H2O)2] · (H2O)3; a=18.271 (1) A, b=11.340 (1) A, c=7.8946 (4) A, β=90.69 (5)°, V=1633.1 (2) A3, [Ni(C4O4)(C10H8)(H2O)2](H2O)1.7). In the crystal structures the metal atoms are coordinated by two squarate dianions, two 4,4′-bipyridine ligands and two water molecules. The metal atoms are connected via the squarate dianions and the 4,4′-bipyridine ligands into layers, which interpenetrate forming a three-dimensional coordination network. This arrangement yields channels in which additional water molecules are embedded. Thermoanalytic investigations show that upon heating the channel water is removed in the first step and that the water coordinated to the metal atoms is emitted in the second step. Both steps are fully reversible with the former reaction proceeding via a topotactic reaction. The hydration and dehydration of the Compounds are accompanied with a continuous change of the color of the materials. The de- and reintercalation processes were investigated using single crystal structure analysis, X-ray powder diffraction, temperature-dependent X-ray powder diffraction, simultaneous differential thermoanalysis and thermogravimetry coupled to mass spectroscopy, differential scanning calorimetry and time-dependent UV-Vis spectroscopy. The results of the investigations are discussed and compared with those for the previously reported Manganese Compound.
Paul J Chirik - One of the best experts on this subject based on the ideXlab platform.
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synthesis and electronic structure of reduced bis imino pyridine Manganese Compounds
European Journal of Inorganic Chemistry, 2012Co-Authors: Sarah K Russell, Karl Wieghardt, Amanda C Bowman, Emil B Lobkovsky, Paul J ChirikAbstract:The synthesis and electronic structure of reduced aryl-substituted bis(imino)pyridine Manganese Compounds have been explored. Stirring a THF slurry of [(iPrPDI)MnCl2] {iPrPDI = 2,6-(2,6-iPr2–C6H3N=CMe)2C5H3N} with excess Na and catalytic (0.5 mol-%) naphthalene furnished the bis(THF) Compound [(iPrPDI)Mn(THF)2]. Performing the reduction with excess Na(Hg) in toluene furnished the bis(chelate) Manganese Compound [(iPrPDI)2Mn]. For both Compounds, a combination of EPR spectroscopy, magnetic measurements and metrical parameters determined from X-ray diffraction established high-spin MnII Compounds with reduced, redox-active bis(imino)pyridine ligands. Substitution of the THF ligands with carbon monoxide yielded [(iPrPDI)Mn(CO)2], a low-spin MnI, d6 Compound with an experimentally observed bis(imino)pyridine-centred radical. Oxidation and reduction of this Compound furnished [(iPrPDI)Mn(CO)3]+ and [(iPrPDI)Mn(CO)2]–, respectively, and provided a series of three Manganese carbonyl Compounds over three oxidation states. Elucidation of the electronic structure of these Compounds established that oxidation events within the series are ligand- rather than Manganese-based, most likely a result of the stable low-spin MnI, d6 electron configuration imparted by the strong-field carbonyl ligands.
Jan Greve - One of the best experts on this subject based on the ideXlab platform.
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synthesis crystal structures and investigations on the dehydration reaction of the new coordination polymers poly diaqua μ2 squarato o o μ2 4 4 bipyridine n n me ii hydrate me co ni fe
Journal of Solid State Chemistry, 2003Co-Authors: Jan Greve, Inke Jes, Christian NatherAbstract:Abstract The three new isostructural coordination polymers poly[diaqua-(μ2-squarato-O,O′)-(μ2-4,4′-bipyridine-N,N′)Me(II)] hydrate (Me=Fe, Co, Ni) were prepared by hydrothermal reaction. All Compounds are isostructural and crystallize in the monoclinic space group P21/c with 4 formula units in the unit cell (a=18.893 (1) A, b=11.450 (1) A, c=8.0985 (4) A, β=93.032 (5)°, V=1749.5 (2) A3, [Fe(C4O4)(C10H8)(H2O)2]·(H2O)3; a=18.937 (1) A, b=11.342 (1) A, c=8.0545 (5) A, β=91.83 (1)°, V=1725.3 (2) A3, [Co(C4O4)(C10H8)(H2O)2] · (H2O)3; a=18.271 (1) A, b=11.340 (1) A, c=7.8946 (4) A, β=90.69 (5)°, V=1633.1 (2) A3, [Ni(C4O4)(C10H8)(H2O)2](H2O)1.7). In the crystal structures the metal atoms are coordinated by two squarate dianions, two 4,4′-bipyridine ligands and two water molecules. The metal atoms are connected via the squarate dianions and the 4,4′-bipyridine ligands into layers, which interpenetrate forming a three-dimensional coordination network. This arrangement yields channels in which additional water molecules are embedded. Thermoanalytic investigations show that upon heating the channel water is removed in the first step and that the water coordinated to the metal atoms is emitted in the second step. Both steps are fully reversible with the former reaction proceeding via a topotactic reaction. The hydration and dehydration of the Compounds are accompanied with a continuous change of the color of the materials. The de- and reintercalation processes were investigated using single crystal structure analysis, X-ray powder diffraction, temperature-dependent X-ray powder diffraction, simultaneous differential thermoanalysis and thermogravimetry coupled to mass spectroscopy, differential scanning calorimetry and time-dependent UV-Vis spectroscopy. The results of the investigations are discussed and compared with those for the previously reported Manganese Compound.
Reedijk Jan - One of the best experts on this subject based on the ideXlab platform.
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Coexistence of Spin Canting and Metamagnetism in a One-Dimensional Mn(II) Compound Bridged by Alternating Double End-to-End and Double End-On Azido Ligands and the Analog Co(II) Compound
KnightScholar, 2021Co-Authors: Benamara Nesrine, Setifi Zouaoui, Yang Chen-i, Bernès Sylvain, Geiger, David K., Kürkçüoğlu, Güneş Süheyla, Setifi Fatima, Reedijk JanAbstract:Two new Compounds of general formula [M(N3)2(dmbpy)] in which dmbpy = 5,5′-dimethyl-2,2′-bipyridine, and M = Mn(II) or Co(II), have been solvothermally synthesized and characterized structurally and magnetically. The structures consist of zig-zag polymeric chains with alternating bis-µ(azide-N1)2M and bis-µ(azide-N1,N3)2M units in which the cis-octahedrally based coordination geometry is completed by the N,N’-chelating ligand dmbpy. The molecular structures are basically the same for each metal. The Mn(II) Compound has a slightly different packing mode compared to the Co(II) Compound, resulting from their different space groups. Interestingly, relatively weak interchain interactions are present in both Compounds and this originates from π–π stacking between the dmbpy rings. The magnetic properties of both Compounds have been investigated down to 2 K. The measurements indicate that the Manganese Compound shows spin-canted antiferromagnetic ordering with a Néel temperature of TN = 3.4 K and further, a field-induced magnetic transition of metamagnetism at temperatures below the TN. This finding affords the first example of an 1D Mn(II) Compound with alternating double end-on (EO) and double end-to-end (EE) azido-bridged ligands, showing the coexistence of spin canting and metamagnetism. The cobalt Compound shows a weak ferromagnetism resulting from a spin-canted antiferromagnetism and long-range magnetic ordering with a critical temperature, TC = 16.2 K
Jan Reedijk - One of the best experts on this subject based on the ideXlab platform.
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coexistence of spin canting and metamagnetism in a one dimensional mn ii Compound bridged by alternating double end to end and double end on azido ligands and the analog co ii Compound
Magnetochemistry, 2021Co-Authors: Nesrine Benamara, Zouaoui Setifi, Cheni Yang, Sylvain Bernes, David K Geiger, Gunes Suheyla Kurkcuoglu, Fatima Setifi, Jan ReedijkAbstract:Two new Compounds of general formula [M(N3)2(dmbpy)] in which dmbpy = 5,5′-dimethyl-2,2′-bipyridine, and M = Mn(II) or Co(II), have been solvothermally synthesized and characterized structurally and magnetically. The structures consist of zig-zag polymeric chains with alternating bis-µ(azide-N1)2M and bis-µ(azide-N1,N3)2M units in which the cis-octahedrally based coordination geometry is completed by the N,N’-chelating ligand dmbpy. The molecular structures are basically the same for each metal. The Mn(II) Compound has a slightly different packing mode compared to the Co(II) Compound, resulting from their different space groups. Interestingly, relatively weak interchain interactions are present in both Compounds and this originates from π–π stacking between the dmbpy rings. The magnetic properties of both Compounds have been investigated down to 2 K. The measurements indicate that the Manganese Compound shows spin-canted antiferromagnetic ordering with a Neel temperature of TN = 3.4 K and further, a field-induced magnetic transition of metamagnetism at temperatures below the TN. This finding affords the first example of an 1D Mn(II) Compound with alternating double end-on (EO) and double end-to-end (EE) azido-bridged ligands, showing the coexistence of spin canting and metamagnetism. The cobalt Compound shows a weak ferromagnetism resulting from a spin-canted antiferromagnetism and long-range magnetic ordering with a critical temperature, TC = 16.2 K.