六二酸盐 (IV) 离子:合成,特性和分子结构
Alexander C Filippou1, Peter Portius, Gregor Schnakenburg
1Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Strasse 2, 12489 Berlin, Germany. filippou@chemie.hu-berlin.de
Journal of the American Chemical Society
|October 17, 2002
概括
研究人员合成了一种新型的化合物, bis ((三) ) 氨六二酸盐,含有高含量. 这种稳定的盐在高温下分解,产生气和其他产物.
科学领域:
- 无机化学 无机化学
- 材料科学 材料科学 材料科学
- 协调化学 协调化学
背景情况:
- 的亚复合物由于它们的高含量和潜在的能量特性而引起人们的兴趣.
- 之前的研究已经探讨了各种基甲酸盐,但基于的六酸复合物不太常见.
研究的目的:
- 为了合成和表征一种新型的六二盐.
- 为了研究合成化合物的热稳定性和分解途径.
- 为了确定六二酸盐离子的结构和电子特性.
主要方法:
- 从四化和 bis ((三) 酸) 酸和 bis ((三) 酸) 酸合成 bis ((三) 酸) 六酸.
- 热分析包括热重力测量分析 (TG-DTA) 以评估稳定性和分解温度.
- 进行X射线晶体学以确定盐的晶体结构.
- 光谱技术 (IR,拉曼,29Si,14NNMR) 和结构分析和电子分析的计算方法.
主要成果:
- 实现了对六二盐 (PPN) 2[Si(N3) 6的选择性合成.
- 该化合物具有显著的热稳定性,在214°C化,在256°C和321°C发生分解.
- 晶体结构显示了离散的PNP+和一种罕见的八面体[Si(N3) 6]2-离子,具有S6对称性和90%的含量.
- 光谱和计算数据证实,溶液中存在完好无损的具有S6对称性的[Si(N3) 6) 2-离子.
结论:
- 一种新型的,高度的六二盐已经成功合成和表征.
- 该化合物表现出显著的热稳定性,具有定义的分解阶段.
- [Si(N3) 6) 2 - 离子具有罕见的八面体SiN6框架,代表了酸金属酸中含量的新基准.
相关概念视频
02:54Ions as Acids and Bases
Salts with Acidic Ions
Salts are ionic compounds composed of cations and anions, either of which may be capable of undergoing an acid or base ionization reaction with water. Aqueous salt solutions, therefore, may be acidic, basic, or neutral, depending on the relative acid-base strengths of the salt’s constituent ions. For example, dissolving the ammonium chloride in water results in its dissociation, as described by the equation:
Salts are ionic compounds composed of cations and anions, either of which may be capable of undergoing an acid or base ionization reaction with water. Aqueous salt solutions, therefore, may be acidic, basic, or neutral, depending on the relative acid-base strengths of the salt’s constituent ions. For example, dissolving the ammonium chloride in water results in its dissociation, as described by the equation:
03:05Acid Strength and Molecular Structure
Binary Acids and Bases
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with increasing...
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with increasing...
01:15Carboxylic Acid Derivatives: Overview
Carboxylic acid derivatives are formed by replacing the hydroxyl group of carboxylic acids with a different functional group. The most common carboxylic acid derivatives are:
01:28Structures of Carboxylic Acid Derivatives
Structure of Carboxylic Acid Derivatives
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...
01:01Acid Halides to Carboxylic Acids: Hydrolysis
Hydrolysis of acid halides is a nucleophilic acyl substitution reaction in which acid halides react with water to give carboxylic acids. The reaction occurs readily and does not require acid or a base catalyst.
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic acid...
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic acid...
01:12Acid Halides to Esters: Alcoholysis
Alcoholysis is a nucleophilic acyl substitution reaction in which an alcohol functions as a nucleophile. Acid halides react with alcohol to produce esters. The mechanism proceeds in three steps: