酸化状態III,IV,Vのマンガン酸ナトリド複合体:合成と電子構造
Henning Kropp1, Amanda E King, Marat M Khusniyarov
1Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander University of Erlangen-Nuremberg, Egerlandstrasse 1, Erlangen, Germany.
Journal of the American Chemical Society
|August 28, 2012
まとめ
研究者らは,三足のトリス・カルベン・リガンドを用いて新しいマンガン・ニトリドを合成した. 本研究は,Mn (IV),Mn (V),Mn (III) を含む様々な酸化状態におけるマンガン酸ナトリドの特徴を詳細に説明し,ユニークな電子基底状態を明らかにしています.
科学分野:
- 無機化学 無機化学とは
- 有機金属化学 有機金属化学
- マテリアルサイエンス 材料科学
背景:
- マンガン酸ナトリドは,様々な触媒プロセスにおける重要な中間物質である.
- マンガン酸ナトリドの電子構造と反応性を理解することは,新しい触媒の開発の鍵です.
- トリポダルのケラチングリガンドは,金属複合体にとってユニークな調整環境を提供します.
研究 の 目的:
- 三脚のトリス・カルベン・リガンドの枠組みの中で,一連のマンガン・ニトリドを合成し,特徴づけること.
- 異なるマンガンの酸化状態の電子特性と基底状態を調査する.
- マンガンニトリドの安定性と反応性に対するリガンドフレームワークの影響を調査する.
主な方法:
- マンガンのアジド前駆物の光分解.
- スペクトロスコープによる特徴付け (例えば,UV-Vis,EPR).
- 密度関数理論 (DFT) による計算.
主要な成果:
- 分子Mn(IV) ニトリド複合体, [(TIMEN(xyl)) Mn(N) ]](+) を二重基底状態で分離した.
- 5等価のMn (V) ニトリド,Mn (N) ]2+を合成し,前述の四角形同類物とは異なる三重基底状態を示した.
- 三価種のMn (((N)) 種,TIMEN (((xyl)) Mn (((N)) の特徴は,中性で非磁性で低スピンのd (((4) 複合体である.
結論:
- 三脚のトリス・カルベン・リガンド・フレームワークは,多様なマンガン・ニトリド種を安定させる.
- マンガン酸ナトリドの電子基底状態は酸化状態と協調幾何学に敏感である.
- この研究は,触媒と材料科学に関連するマンガン酸ナトリドの基本的な化学に関する洞察を提供します.
関連する概念動画
02:58Properties of Transition Metals
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
02:42Valence 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...
02:54Coordination Compounds and Nomenclature
In most main group element compounds, the valence electrons of the isolated atoms combine to form chemical bonds that satisfy the octet rule. For instance, the four valence electrons of carbon overlap with electrons from four hydrogen atoms to form CH4. The one valence electron leaves sodium and adds to the seven valence electrons of chlorine to form the ionic formula unit NaCl (Figure 1a). Transition metals do not normally bond in this fashion. They primarily form coordinate covalent bonds, a...
02:57Coordination Number and Geometry
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
03:02Colors 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.
02:34Structural Isomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...