用于非线性光学的二基电子受体的分子盐
Benjamin J Coe1, James A Harris, Bruce S Brunschwig
1School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK. b.coe@man.ac.uk
Journal of the American Chemical Society
|March 10, 2005
概括
研究人员研究了具有二极电子受体的新双极染色体. 这些分子在带电化合物中表现出显著增强的光学特性和罕见的二维非线性光学反应.
科学领域:
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
- 非线性光学是非线性光学.
背景情况:
- 二极色谱对非线性光学 (NLO) 材料至关重要.
- 电子受体组显著影响染色体的特性.
- 迪卡特单位以其强大的电子接受能力而闻名.
研究的目的:
- 为了合成和描述新型的双极色素离子体,其中包含基于二酸的电子受体.
- 研究这些新化合物的光学和电子特性.
- 评估它们在非线性光学应用中的潜力,特别关注超极化性和NLO响应维度.
主要方法:
- 斯塔克光谱法被用来探测电子结构和NLO属性.
- 进行了分子轨道 (MO) 计算,以补充实验数据并了解电子特征.
- 进行了与相关的 stilbazolium 染色体进行比较.
主要成果:
- 双单位赋予强大的电子接受性质,导致相比于stilbazolium类似物显著更大的静态第一个超极化性 (β0).
- 实验和计算数据证实了增强的光学和电子性能.
- 一种化合物表现出强烈的二维 (2D) 方位非线性光学响应.
结论:
- 基于二酸盐的染色体提供了优越的静态第一超极化性.
- 该研究提供了一个充电分子表现出强烈的二维二进制NLO反应的罕见例子.
- 这些发现突显了含二酸的充电分子在先进的NLO应用中的潜力.
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.
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:
Lewis Acids and Bases
In 1923, G. N. Lewis proposed a generalized definition of acid-base behavior in which acids and bases are identified by their ability to accept or to donate a pair of electrons and form a coordinate covalent bond.
A coordinate covalent bond (or dative bond) occurs when one of the atoms in the bond provides both bonding electrons. For example, a coordinate covalent bond occurs when a water molecule combines with a hydrogen ion to form a hydronium ion. A coordinate covalent bond also results when...
A coordinate covalent bond (or dative bond) occurs when one of the atoms in the bond provides both bonding electrons. For example, a coordinate covalent bond occurs when a water molecule combines with a hydrogen ion to form a hydronium ion. A coordinate covalent bond also results when...
Potentiometry: Membrane Electrodes
Membrane electrodes, also known as p-ion electrodes, use membranes that selectively interact with free analyte ions, generating a potential difference across the membrane. The resulting membrane potential, known as the asymmetry potential, is not zero even when analyte concentrations on both sides of the membrane are equal. The membrane's response is typically not selective to a single analyte but proportional to the concentration of all ions in the sample solution capable of interacting at the...
Ionic Association
The ionic association is the association of oppositely charged ions in an electrolyte solution to form ion pairs. Bjerrum defined ion pairs as two oppositely charged ions whose electrostatic attraction exceeds the thermal energy of the system, typically expressed as 2kT. Electrostatic attraction depends on ionic charge, separation distance, and the dielectric constant of the medium. Thermal energy, represented by kT, reflects the tendency of ions to move independently due to molecular motion.
Theory of Strong Electrolytes
The interionic forces of the strong electrolytes depend on the solvent's dielectric constant, which is the ability of a solvent to store electrical energy, based on its polarizability. and the solution's concentration. In high-dielectric solvents and in dilute solutions, weak electrostatic forces keep ions apart. However, in low-dielectric solvents or concentrated solutions, stronger interionic forces may cause ions to pair up as ionic doublets despite being fully ionized. The theory of strong...


