プルーシアンブルーの類型で高プロトン伝導性と,磁気順序による干渉効果
Shin-Ichi Ohkoshi1, Kosuke Nakagawa, Keisuke Tomono
1Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. ohkoshi@chem.s.u-tokyo.ac.jp
Journal of the American Chemical Society
|April 28, 2010
まとめ
コバルトとバナジウムコーディネーションポリマーは高陽子伝導性を示しています. 研究者らは,磁気相変化温度近くの磁気配列とイオン輸送の相互作用を発見した.
科学分野:
- マテリアルサイエンス 材料科学
- 固体化学 固体化学
- マグネチズム (磁気) とは
背景:
- 協調ポリマーにおける陽子伝導性は,エネルギーアプリケーションにおいて極めて重要です.
- 磁気特性とイオン輸送の関係を理解することは,継続的な課題です.
研究 の 目的:
- コバルトとヴァナジウムに基づく新しい協調ポリマーを合成し,特徴づけること.
- これらの材料の陽子伝導性と磁気特性を調査する.
- マグネティック・オーダーリングとイオン伝導の結合を調査する.
主な方法:
- コバルト ((II) ヘクサシアノコバルト ((III) とバナジウム ((II) ヘクサシアノコバルト ((III) コーディネーションポリマーの合成.
- 電気化学阻抗スペクトロスコーピーを用いたプロトンの伝導性測定.
- 磁気順序と相変遷を決定するための磁気感受性測定.
主要な成果:
- 高陽子伝導度1.2 x 10 (((-3) S cm ((-1) の Co[Cr (((CN) ((6)) ](2/3).zH (((2) O と 1.6 x 10 ((-3) S cm ((-1) の V[Cr (((CN)) ((6) ](2/3).zH (((2) O が達成されました.
- 磁気順序とイオン伝導の間の干渉効果は,磁気相変遷温度を下回って観察されました.
- 結果は,陽子輸送に磁気配列が有意な影響を与えていることを示しています.
結論:
- コバルトとヴァナジウムの協調ポリマーは,潜在的な応用のための有望な陽子伝導性を示しています.
- 磁気性およびイオン性特性の間の観測された結合は,機能的な材料の設計のための新しい道を開く.
- 磁性イオン結合のメカニズムに関するさらなる研究は,電気化学装置のための高度な材料につながる可能性があります.
関連する概念動画
Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
π Electron Effects on Chemical Shift: Overview
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0, resulting in...
Paramagnetism
Paramagnets are materials with unpaired electrons that possess a finite magnetic moment. In the absence of a magnetic field, these moments are randomly oriented, and thus the net moment is zero. Under an external field, a torque acting on the moments tends to align them along the field's direction. However, the random thermal motion of electrons produces a torque opposite to the external field and tries to disorient the moments. These two competing effects align only a few moments along the...
π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds
In aromatic compounds, such as benzene, the circulation of (4n + 2) π-electrons sets up a diamagnetic or diatropic ring current around the perimeter of the molecule. This current induces a magnetic field that opposes the external field inside the ring and reinforces it on the outside. The protons in benzene are deshielded and exhibit high chemical shifts in the range 6.5–8.5 ppm. The shielding effect at the center of the ring is evident in complex aromatic molecules, such as annulenes. In...
Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...


