一个单体高旋转Mn(V) -oxo复合物的制备和特性
Taketo Taguchi1, Rupal Gupta, Benedikt Lassalle-Kaiser
1Department of Chemistry, University of California-Irvine, 1102 Natural Sciences II, Irvine, California 92697, USA.
Journal of the American Chemical Society
|January 12, 2012
概括
研究人员报告了一种新型的高旋转氧 ((V) 复合体,与典型的低旋转变体不同. 这一发现促进了对生物和合成化学中氧物种的理解.
科学领域:
- 无机化学 无机化学 有机化学
- 生物有机化学 生物有机化学
- 摄影化学的使用.
背景情况:
- 氧 ((V) 种在光合作用等生物过程中至关重要.
- 大多数已知的单核Mn(V) -oxo复合体表现出四边形对称性和低旋转状态.
研究的目的:
- 为了合成和表征一种新的高旋转氧 (V) 复合物.
- 为了研究这个新的复杂的结构和电子特性.
主要方法:
- 从一种氧化前体中合成一种新的氧化 (V) 复合物.
- 使用光学和电子磁共振 (EPR) 光谱仪监测的氧化实验.
- 通过共振拉曼光谱和Mn KβX射线发射光谱进行表征.
主要成果:
- 成功制备了一个具有三角形对称性的高旋转Mn(V) -oxo复合体.
- EPR光谱学证实了在g=4.01处的S=1信号,具有特有的超细图案.
- 共振拉曼和Mn KβX射线发射光谱为氧联体和高旋转MnV) 中心提供了证据.
结论:
- 这项研究提供了第一个具有三角对称性的高旋转氧 (V) 复合体的例子.
- 这些发现扩大了氧物种已知的化学成分和它们在催化中的潜在作用.
- 描述的复合物为研究电子转移和反应性中间体提供了新的途径.
相关概念视频
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...
Radical Oxidation of Allylic and Benzylic Alcohols
Activated manganese(IV) oxide can selectively oxidize allylic and benzylic alcohols via a radical intermediate mechanism. Primary allylic alcohols are oxidized to aldehydes, while secondary allylic alcohols yield ketones. The redox reaction of potassium permanganate with an Mn(II) salt such as manganese sulfate (under either alkaline or acidic conditions), followed by thorough drying, yields the oxidizing agent: activated MnO2. While MnO2 is insoluble in the solvents used for the reaction, the...
Properties of Organometallic Compounds
Organometallic compounds are compounds that contain a carbon–metal bond. Carbon belongs to an organyl group like alkyl, aryl, allyl, or benzyl groups. The metal can be from Group I or Group II of the periodic table, a transition metal, or a semimetal.
Oxidation of Alkenes: Syn Dihydroxylation with Potassium Permanganate
Alkenes can be dihydroxylated using potassium permanganate. The method encompasses the reaction of an alkene with a cold, dilute solution of potassium permanganate under basic conditions to form a cis-diol along with a brown precipitate of manganese dioxide.
Preparation of Amines: Reduction of Oximes and Nitro Compounds
Oximes can be reduced to primary amines using catalytic hydrogenation, hydride reduction, or sodium metal reduction. The reduction of aliphatic and aromatic nitro compounds to primary amines takes place by either catalytic hydrogenation or by using active metals like Fe, Zn, and Sn in the presence of an acid.
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...


