在Cu(110上C60/corannulene):一个表面支的可双相形态的buckybowl-buckyball主机-客户系统
Wende Xiao1, Daniele Passerone, Pascal Ruffieux
1nanotech@surfaces Laboratory, Empa, Swiss Federal Laboratories for Materials Testing and Research, Feuerwerkerstrasse 39, 3602 Thun, Switzerland.
Journal of the American Chemical Society
|March 15, 2008
概括
研究人员创建了表面支持的冠烯-富勒烯复合体,克服了超分子化学的挑战. 可变温度研究揭示了冠烯晶格上的两个不同的C60状态,具有热激活过渡.
科学领域:
- 超分子化学 超分子化学
- 材料科学 材料科学 材料科学
- 表面科学是一门学科.
背景情况:
- 冠烯 (COR) buckybowls被认为是充烯C60.0的理想宿主.
- 直接复合C60和COR一直是超分子化学的一个持续挑战.
- 了解纳米级的宿主-客人相互作用对于设计先进材料至关重要.
研究的目的:
- 为了实现和表征表面支持的冠烯-富勒烯 (COR-C60) 主机-客体复合体.
- 研究C60在COR格子上的结合动态和结构状态.
- 阐明控制这些复合物的形成和稳定性的因素.
主要方法:
- 沉积的C60分子在一个预先形成的corannulene网格上的Cu(110) 表面.
- 可变温度扫描道显微镜 (STM) 探测表面结构和动态.
- 对不同C60状态的结合能和碗球分离的分析.
主要成果:
- 成功形成表面支的COR-C60宿主-客座综合体.
- 对C60在COR格子上被吸附的两个不同的状态的观察,它们在结合能量和空间布局上有所不同.
- 证明从弱结合状态过渡到强结合的复合体是热激活的.
结论:
- 该研究通过采用表面支持方法克服了直接COR-C60复杂化的挑战.
- 在C60结合中观察到的双稳定性归因于corannulene-corannulene和corannulene-fullerene相互作用之间的相互作用.
- 这些发现提供了对纳米尺度宿主-客化学的基本见解,并为新型功能材料铺平了道路.
相关概念视频
02:02Chair Conformation of Cyclohexane
The chair conformation is the most stable form of cyclohexane due to the absence of angle and torsional strain. The absence of angle strain is a result of cyclohexane’s bond angle being very close to the ideal tetrahedral bond angle of 109.5° in its chair conformer. Similarly, the torsional strain is also absent owing to the perfectly staggered arrangement of bonds.
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
02:11Conformations 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,...
02:18Network Covalent Solids
Network covalent solids contain a three-dimensional network of covalently bonded atoms as found in the crystal structures of nonmetals like diamond, graphite, silicon, and some covalent compounds, such as silicon dioxide (sand) and silicon carbide (carborundum, the abrasive on sandpaper). Many minerals have networks of covalent bonds.
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
02:58Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
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02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
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Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
01:24π Molecular Orbitals of 1,3-Butadiene
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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 number...
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 number...