相关实验视频
Updated: Jun 8, 2026

06:45
Negative Additive Manufacturing of Complex Shaped Boron Carbides
Published on: September 18, 2018
在小型碳混合集群中,结构从平面过渡到线性过渡:C(x) B(5-x) - (x = 1-5)
Lei-Ming Wang1, Boris B Averkiev, Jordan A Ramilowski
1Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
Journal of the American Chemical Society
|September 23, 2010
概括
这项研究揭示了混合碳集群中的结构转变. 随着碳含量增加,这些五个原子集群从平面变为线性排列,影响材料特性.
科学领域:
- 计算化学计算化学
- 材料科学 材料科学 材料科学
- 原子和分子物理 原子和分子物理
背景情况:
- 对于纯碳 (线性) 和 (平面) 集群,存在不同的结构偏好.
- 之前的研究已经确定了B的平面结构{5) }和C的线性结构{5) }.
- 了解混合集群对于预测新材料的特性至关重要.
研究的目的:
- 为了研究混合-碳集群的结构演变,C(x) B(5-x) ((-).
- 为了确定发生结构转变的关键碳含量.
- 为了将这些混合集群中的结构变化与电子特性相关联.
主要方法:
- 生产的C(x) B(5-x) ((-) (x = 1-5) 集群.
- 使用光电子光谱学进行表征.
- 几何和电子结构的理论研究.
主要成果:
- 在x=2和x=3.3之间确定了平面到线性结构过渡.
- 富含的集群 (CB(4) ((-) 和C(2) B(3) ((-)) 采用平面结构.
- 富含碳的集群 (C(3) B(2) ((-) 和C(4) B(-)) 呈现线性结构.
结论:
- 混合B/C集群的结构行为高度依赖于碳分数.
- 这项研究阐明了从平面到线性几何学的基本过渡在小集群中.
- 这些发现为设计具有可调节性质的新材料提供了洞察力.
相关概念视频
Hybridization of Atomic Orbitals I
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
Coordination Number and Geometry
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
Hybridization of Atomic Orbitals II
sp3d and sp3d 2 Hybridization
Conformations of Cyclohexane
Cyclohexane does not exist in a planar form due to the high angle and torsional strain it would experience in the planar structure. Instead, it adopts non-planar chair and boat conformations.
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
VSEPR Theory and the Basic Shapes
Overview of VSEPR Theory
Hydroboration-Oxidation of Alkenes
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.

