结构和离子交换新型玻酸盐的结构和离子交换特性,其道结构由Na+"模拟"
Jesse L C Rowsell1, Nicholas J Taylor, Linda F Nazar
1Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
Journal of the American Chemical Society
|June 6, 2002
概括
合成了一种新的无水酸盐,Na2Co2B12O21,并被发现是第一个具有道网络的代谢酸盐. 它的离子是可交换的,形成一个非状泽型材料.
科学领域:
- 无机化学 无机化学
- 材料科学 材料科学 材料科学
- 晶体工程公司 晶体工程公司
背景情况:
- 酸盐是一种多样化的无机化合物,具有各种结构动机.
- 石和型是结晶的微孔材料,在催化和分离中具有重要的应用.
- 新型非状泽型材料的合成对扩展材料性质具有很大的兴趣.
研究的目的:
- 为了合成和表征一种新的无水酸化合物.
- 研究合成的酸盐的结构性质,特别是其网络维度.
- 探索新材料的离子交换能力和潜在的热型行为.
主要方法:
- 合成流量方法,以获得单晶体.
- 单晶X射线衍射用于精确的结构确定.
- 离子交换实验,以评估离子替代和水的吸收.
主要成果:
- 通过流量方法成功合成无水Na2Co2B12O21.
- 结构的精细化揭示了在代谢结构 (空间组I2/a) 内的新道网络.
- 证明了Na+离子与Li+的交换和水的吸收,形成Li2 ((H2O) 2Co2B12O21,一种非状的热型.
结论:
- Na2Co2B12O21是第一个表现出道框架的代谢物.
- 由于其离子交换特性,该材料表现出热型特征.
- 这一发现为开发新的非状材料开辟了道路,其潜在应用类似于热石.
相关概念视频
Ionic Bonding and Electron Transfer
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
Ionic Crystal Structures
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Ions 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:
Resonance and Hybrid Structures
According to the theory of resonance, if two or more Lewis structures with the same arrangement of atoms can be written for a molecule, ion, or radical, the actual distribution of electrons is an average of that shown by the various Lewis structures.
Resonance Structures and Resonance Hybrids
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N–O and N=O bonds.
Resonance Structures and Resonance Hybrids
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N–O and N=O bonds.
Structures 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...
Structure of Amines
The hybridized nitrogen atom in amines possesses a lone pair of electrons and is bound to three substituents with a bond angle of around 108°, which is less than the tetrahedral angle of 109.5°. However, the C–N–H bond angle is slightly larger at 112°, with a carbon–nitrogen bond length of 147 pm. This carbon–nitrogen bond length of of amines is longer than the carbon–oxygen bond of alcohols (143 pm) but shorter than alkanes’ carbon–carbon bond (154 pm). These aspects are illustrated in Figure...


