合成乌兰离子的imido类似物
Trevor W Hayton1, James M Boncella, Brian L Scott
1Chemistry Division, MS J514, MS B268, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
概括
研究人员通过用联体取代氧气,合成了离子的新型imido类似物UO(2+) 2. 这些新的复合体具有线性N-U-N键,并且5f和6d电子在结合中具有显著的参与.
科学领域:
- 无机化学 无机化学
- 有机金属化学 有机金属化学
- 化学 的化学
背景情况:
- 乌兰离子,UO(2+) 2 是一种已知的具有线性O-U-O键的复合体.
- 探索与不同配体的类似物可以提供有关结合和反应性的见解.
研究的目的:
- 为了合成和表征乌兰离子的imido类似物,UO(2+) 2.2.
- 研究这些新型-化合物的结构和电子特性.
- 使用理论计算量化金属-合物化学结合.
主要方法:
- 合成化物复合物:U(NtBu) 2I2 ((THF) 2) 和U(NPh) 2I2 ((THF) 3.
- 使用标准分析技术进行完整的表征,包括X射线晶体学.
- 混合密度函数理论 (DFT) 计算来量化化学结合.
主要成果:
- 成功合成了两个乌兰离子的imido类似物,UO(2+) 2.2.
- 射线晶体学证实了线性N-U-N链接和非常短的U-N键.
- DFT计算显示,的5f和6d电子在U-N结合中具有强烈的参与.
结论:
- 合成的imido复合体是乌兰离子,UO(2+) 2.2. 的有效类型.
- N-U-N 连接和短 U-N 键是这些模态化合物的特征.
- 电子结构计算突出了f-和d-轨道在-结合中的重要作用.
相关概念视频
Aldehydes and Ketones with Amines: Imine and Enamine Formation Overview
Primary amines react with carbonyl compounds—aldehydes and ketones—to generate imines. Imines consist of a C=N double bond and are named Schiff bases after its discoverer—the German chemist Hugo Schiff. On the other hand, secondary amines react with carbonyl compounds to give enamines. In enamines, the presence of a C=C double bond adjacent to the nitrogen atom leads to the delocalization of the lone pair.
Acid Halides to Amides: Aminolysis
Aminolysis is a nucleophilic acyl substitution reaction, where ammonia or amines act as nucleophiles to give the substitution product. Acid halides react with ammonia, primary amines, and secondary amines to yield primary, secondary, and tertiary amides, respectively.
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
Basicity of Heterocyclic Aromatic Amines
Heterocyclic amines, where the N atom is a part of an alicyclic system, are similar in basicity to alkylamines. Interestingly, the heterocyclic amine having a nitrogen atom as part of an aromatic ring has much less basicity than its corresponding alicyclic counterpart. For this reason, as presented in Figure 1, piperidine (pKb = 2.8) is significantly more basic than pyridine (pKb = 8.8).
Amines to Alkenes: Hofmann Elimination
Alkenes can be obtained from amines via an E2 elimination. The amine is first converted into a good leaving group, such as a quaternary ammonium salt. This is accomplished by treating the amine with an excess of alkyl halide, which results in a halide salt. Next, the halide salt is transformed into a hydroxide salt that functions as a base to enable elimination.
Under thermal conditions, the hydroxide can abstract a proton from the β carbon; this generates an alkene with the simultaneous...
Under thermal conditions, the hydroxide can abstract a proton from the β carbon; this generates an alkene with the simultaneous...
Aldehydes and Ketones with Amines: Imine Formation Mechanism
Imine formation involves the addition of carbonyl compounds to a primary amine. It begins with the generation of carbinolamine through a series of steps involving an initial nucleophilic attack and then several proton transfer reactions. The second part includes the elimination of water, as a leaving group, to give the imine.
Imines are formed under mildly acidic conditions. A pH of 4.5 is ideal for the reaction.
If the pH is low or the solution is too acidic, the reaction slows down in the...
Imines are formed under mildly acidic conditions. A pH of 4.5 is ideal for the reaction.
If the pH is low or the solution is too acidic, the reaction slows down in the...
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...


