Solid- and solution-state studies of the novel μ-dicyanamide-bridged dinuclear spin-crossover system {[Fe(bztpen)]2[μ-N(CN) 2]}(PF6)3·nH2O
The mononuclear diamagnetic compound {Fe(bztpen)[N(CN)2]} (PF6)CH3OH (1) (bztpen = N-benzyl-N,N′,N′- tris(2-pyridylmethyl)ethylenediamine) has been synthesized and its crystal structure studied. Complex 1 can be considered to be the formal pre-cursor of two new dinuclear, dicyanamide-bridged iron(II...
| المؤلفون الرئيسيون: | , , , , , , |
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| التنسيق: | Journal article |
| اللغة: | English |
| منشور في: |
2005
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| _version_ | 1826282326681714688 |
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| author | Ortega-Villar, N Thompson, A Muñoz, M Ugalde-Saldívar, V Goeta, A Moreno-Esparza, R Real, J |
| author_facet | Ortega-Villar, N Thompson, A Muñoz, M Ugalde-Saldívar, V Goeta, A Moreno-Esparza, R Real, J |
| author_sort | Ortega-Villar, N |
| collection | OXFORD |
| description | The mononuclear diamagnetic compound {Fe(bztpen)[N(CN)2]} (PF6)CH3OH (1) (bztpen = N-benzyl-N,N′,N′- tris(2-pyridylmethyl)ethylenediamine) has been synthesized and its crystal structure studied. Complex 1 can be considered to be the formal pre-cursor of two new dinuclear, dicyanamide-bridged iron(II) complexes with the generic formula {[(Fe(bztpen)]2[μN(CN)2]}(PF6) 3·nH2O (n = 1 (2) or 0 (3)), which have been characterized in the solid state and in solution. In all three complexes, the iron atoms have a distorted [FeN6] octahedral coordination defined by a bztpen ligand and a terminal (1) or a bridging dicyanamide ligand (2 and 3). In the solid state, 2 and 3 can be considered to be molecu lar isomers that differ by the relative position of the phenyl ring of the two {Fe(bztpen)[N(CN)2]}+ halves (cis and trans, respectively). Depending on the texture of the sample, 2 exhibits para-magnetic behavior or displays a very incomplete spin transition at atmospheric pressure. Complex 3 undergoes a gradual two-step spin transition with no observed hysteresis in the solid state. Both steps are approximately 100 K wide, centered at ≈200 K and ≈ 350 K, with a plateau of approximately 80 K separating the transitions. The crystal structure of 3 has been determined in steps of approximately 50 K between 400 K and 90 K, which provides a fascinating insight into the structural behavior of the complex and the nature of the spin transition. Order-disorder transitions occur in the dicyanamide bridge and the PF6- ions simultaneously, with the spin-crossover behavior suggesting that these transitions may trigger the two-step character. In solution, 2 and 3 display very similar continuous spin conversions. Electrochemical studies of 2 and 3 show that the voltammograms are typical of dimeric systems with electronic coupling of the metals through the dicyanamide ligand. © 2005 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim. |
| first_indexed | 2024-03-07T00:42:10Z |
| format | Journal article |
| id | oxford-uuid:836c69a3-17d4-4a04-b32c-b89f1822bd1f |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T00:42:10Z |
| publishDate | 2005 |
| record_format | dspace |
| spelling | oxford-uuid:836c69a3-17d4-4a04-b32c-b89f1822bd1f2022-03-26T21:44:00ZSolid- and solution-state studies of the novel μ-dicyanamide-bridged dinuclear spin-crossover system {[Fe(bztpen)]2[μ-N(CN) 2]}(PF6)3·nH2OJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:836c69a3-17d4-4a04-b32c-b89f1822bd1fEnglishSymplectic Elements at Oxford2005Ortega-Villar, NThompson, AMuñoz, MUgalde-Saldívar, VGoeta, AMoreno-Esparza, RReal, JThe mononuclear diamagnetic compound {Fe(bztpen)[N(CN)2]} (PF6)CH3OH (1) (bztpen = N-benzyl-N,N′,N′- tris(2-pyridylmethyl)ethylenediamine) has been synthesized and its crystal structure studied. Complex 1 can be considered to be the formal pre-cursor of two new dinuclear, dicyanamide-bridged iron(II) complexes with the generic formula {[(Fe(bztpen)]2[μN(CN)2]}(PF6) 3·nH2O (n = 1 (2) or 0 (3)), which have been characterized in the solid state and in solution. In all three complexes, the iron atoms have a distorted [FeN6] octahedral coordination defined by a bztpen ligand and a terminal (1) or a bridging dicyanamide ligand (2 and 3). In the solid state, 2 and 3 can be considered to be molecu lar isomers that differ by the relative position of the phenyl ring of the two {Fe(bztpen)[N(CN)2]}+ halves (cis and trans, respectively). Depending on the texture of the sample, 2 exhibits para-magnetic behavior or displays a very incomplete spin transition at atmospheric pressure. Complex 3 undergoes a gradual two-step spin transition with no observed hysteresis in the solid state. Both steps are approximately 100 K wide, centered at ≈200 K and ≈ 350 K, with a plateau of approximately 80 K separating the transitions. The crystal structure of 3 has been determined in steps of approximately 50 K between 400 K and 90 K, which provides a fascinating insight into the structural behavior of the complex and the nature of the spin transition. Order-disorder transitions occur in the dicyanamide bridge and the PF6- ions simultaneously, with the spin-crossover behavior suggesting that these transitions may trigger the two-step character. In solution, 2 and 3 display very similar continuous spin conversions. Electrochemical studies of 2 and 3 show that the voltammograms are typical of dimeric systems with electronic coupling of the metals through the dicyanamide ligand. © 2005 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim. |
| spellingShingle | Ortega-Villar, N Thompson, A Muñoz, M Ugalde-Saldívar, V Goeta, A Moreno-Esparza, R Real, J Solid- and solution-state studies of the novel μ-dicyanamide-bridged dinuclear spin-crossover system {[Fe(bztpen)]2[μ-N(CN) 2]}(PF6)3·nH2O |
| title | Solid- and solution-state studies of the novel μ-dicyanamide-bridged dinuclear spin-crossover system {[Fe(bztpen)]2[μ-N(CN) 2]}(PF6)3·nH2O |
| title_full | Solid- and solution-state studies of the novel μ-dicyanamide-bridged dinuclear spin-crossover system {[Fe(bztpen)]2[μ-N(CN) 2]}(PF6)3·nH2O |
| title_fullStr | Solid- and solution-state studies of the novel μ-dicyanamide-bridged dinuclear spin-crossover system {[Fe(bztpen)]2[μ-N(CN) 2]}(PF6)3·nH2O |
| title_full_unstemmed | Solid- and solution-state studies of the novel μ-dicyanamide-bridged dinuclear spin-crossover system {[Fe(bztpen)]2[μ-N(CN) 2]}(PF6)3·nH2O |
| title_short | Solid- and solution-state studies of the novel μ-dicyanamide-bridged dinuclear spin-crossover system {[Fe(bztpen)]2[μ-N(CN) 2]}(PF6)3·nH2O |
| title_sort | solid and solution state studies of the novel μ dicyanamide bridged dinuclear spin crossover system fe bztpen 2 μ n cn 2 pf6 3·nh2o |
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