相关实验视频

Updated: May 16, 2025

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids

Published on: May 27, 2020

分子的计算设计具有较少的重叠HOMO和LUMO在同一个平面中的分子

¹RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.

The journal of physical chemistry. A

|April 3, 2025

概括

研究人员设计了具有特定π电子计数且没有键交替的新型环素分子,以实现单元和三元兴奋状态 (ΔEST) 之间的负能量差异. 这一突破扩大了具有理想光物理性质的材料的分子设计可能性.

科学领域:

计算化学计算化学
材料科学材料科学材料科学
光物理学的光学物理学

背景情况:

单元和三元激发状态 (ΔE_ST) 之间的负能量差异对于先进的材料至关重要,但分子设计是有限的.
实现负 ΔE_ST 需要最大限度地分离最高占有分子轨道 (HOMO) 和最低未占有分子轨道 (LUMO),以最大限度地减少交换相互作用.

研究的目的:

探索超越阿扎芬结构的新型分子设计,以实现负 ΔE_ST.
研究不同π电子系统的环衍生物的电子结构及其对HOMO-LUMO排列和ΔE_ST的影响.

主要方法:

设计并通过计算分析了含有N = 4·n和N = 4·n + 2 π电子的外围循环基的环素分子.
使用单个配置交互,TD-DFT和EOM-CCSD方法计算了HOMO,LUMO,交换交互 (K) 和ΔE_ST.
优化了没有对称性约束的分子结构,以准确评估电子属性.

主要成果:

具有N = 4·n π电子且没有键交替的环素分子表现出最小化的HOMO-LUMO重叠和小交换相互作用 (K).
这些特定结构 (N = 4·n,没有债券交替) 在使用EOM-CCSD计算时显示出负 ΔE_ST.
具有N = 4·n + 2 π电子的分子没有显示所需的最小化HOMO-LUMO重叠.

结论:

对负 ΔE_ST 的分子设计可以通过利用环素结构来扩展到现有的支架之外.
通过特定的π电子配置 (N = 4·n) 最小化HOMO-LUMO重叠,避免键交替是实现负 ΔE_ST 的关键.
这项研究为设计具有可调节光物理性质的新分子为各种应用提供了基础.

更多相关视频

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations

Published on: October 12, 2019

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Published on: April 8, 2020

相关概念视频

Molecular Orbital Theory II

Molecular Orbital Theory II

Molecular Orbital Energy Diagrams

π Molecular Orbitals of 1,3-Butadiene

π Molecular Orbitals of 1,3-Butadiene

Conjugated dienes have lower heats of hydrogenation than cumulated and isolated dienes, making them more stable. The enhanced stabilization of conjugated systems can be understood from their π molecular orbitals.
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the...

Molecular Orbital Theory I

Molecular Orbital Theory I

Overview of Molecular Orbital Theory

Molecular Shapes

Molecular Shapes

Molecules have characteristic shapes that are crucial for their function. The arrangement of various electron groups around the central atom dictates their molecular geometry. Electron pairs in the valence shell of a central atom will adopt an arrangement that minimizes repulsions between the electron pairs by maximizing the distance between them. The valence electrons form either bonding pairs, located primarily between bonded atoms, or lone pairs.
Two regions of electron density in a diatomic...

Molecular Models

Molecular Models

Physical models representing molecular architectures of chemical compounds play essential roles in understanding chemistry. The use of molecular models makes it easier to visualize the structures and shapes of atoms and molecules.

MO Theory and Covalent Bonding

MO Theory and Covalent Bonding

The molecular orbital theory describes the distribution of electrons in molecules in a manner similar to the distribution of electrons in atomic orbitals. The region of space in which a valence electron in a molecule is likely to be found is called a molecular orbital. Mathematically, the linear combination of atomic orbitals (LCAO) generates molecular orbitals. Combinations of in-phase atomic orbital wave functions result in regions with a high probability of electron density, while...