固体中的Al2H6的红外光谱
1Department of Chemistry, University of Virginia, Post Office Box 400319, Charlottesville, VA 22904-4319, USA. lsa@virginia.edu
概括
研究人员合成了二化物 (Al2H6),这是一个以前未知的稳定形式的分子. 在二元化化学中的这一突破为材料科学研究开辟了新的途径.
科学领域:
- 无机化学 无机化学
- 量子化学 是一个量子化学.
- 材料科学 材料科学 材料科学
背景情况:
- 二元化化学在很大程度上未被探索,仅限于聚合物化固体.
- 易挥发的二元化已得到充分证实,与的有限已知的化形式形成鲜明对比.
研究的目的:
- 为了合成和表征一个稳定的,非聚合物的二元化分子.
- 探索化中间体的二元化潜力.
主要方法:
- 在冷温度 (3.5K) 下,激光剥离的原子和气共同沉积.
- 使用紫外线照射进行光解,然后化至6.5K.
- 使用红外光谱学和量子化学计算来识别产品.
主要成果:
- 通过AlH3中间体的二元化,成功合成了Al2H6分子.
- 确定了七个新的红外吸收波段,对应于Al2H6.6.
- 量子化学计算准确地预测了二桥式Al2H6结构的光谱特征.
结论:
- 合成Al2H6代表了二元化化学的重大进步.
- 双桥式Al2H6分子与diborane具有同结构,提供了比较化学见解.
- 这项工作扩大了已知的化的化学成分,并为未来的研究提供了基础.
相关概念视频
IR Spectrum
When infrared (IR) radiation passes through a molecule, the bonds stretch or bend by absorbing the radiation. This absorption creates the molecule's absorption spectrum, which is the plot of its percentage transmittance versus wavenumber.
Transmittance is defined as the ratio of the radiant power passing through a sample to that from the radiation's source. Multiplying the transmittance by 100 gives the percent transmittance (%T), which varies between 100% (no absorption) and 0% (complete...
Transmittance is defined as the ratio of the radiant power passing through a sample to that from the radiation's source. Multiplying the transmittance by 100 gives the percent transmittance (%T), which varies between 100% (no absorption) and 0% (complete...
IR and UV–Vis Spectroscopy of Aldehydes and Ketones
Infrared spectroscopy, also known as vibrational spectroscopy, is mainly used to determine the types of bonds and functional groups in molecules. In aldehydes and ketones, the carbonyl (C=O) bond shows an absorption around 1710 cm-1. The C=O bond vibration of an aldehyde occurs at lower frequencies than that of a ketone. In addition to the C=O absorption in an aldehyde, the aldehydic C–H bond also gives two peaks in the 2700–2800 cm-1 range. This absorption, coupled with the C=O stretching, is...
UV–Vis Spectroscopy: Molecular Electronic Transitions
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this process,...
UV–Vis Spectrometers
The absorbance of UV and visible (UV–visible) radiations is measured using a UV–visible spectrophotometer. Deuterium lamps, which emit UV radiation, and tungsten lamps, which produce radiation in the visible region, are used as light sources in UV–visible spectrophotometers. A monochromator or prism is used for diffraction grating, i.e., to split the incoming radiation into different wavelengths. A system of slits is used to focus the desired wavelength on the sample cell. Samples for...
IR Absorption Frequency: Hybridization
Hydrocarbons such as alkanes, alkenes, and alkynes show characteristic C–H stretching absorption bands. These IR stretching frequencies depend on the hybridization of the involved carbon atom and can be explained in terms of the s character of each hybridized atomic orbital.
Among the sp, sp2, and sp3 hybridized orbitals, sp orbitals have the maximum s character (50%). Consequently, the electrons are held more closely to the nucleus, resulting in stronger and shorter C–H bonds that stretch at a...
Among the sp, sp2, and sp3 hybridized orbitals, sp orbitals have the maximum s character (50%). Consequently, the electrons are held more closely to the nucleus, resulting in stronger and shorter C–H bonds that stretch at a...
IR Frequency Region: Alkene and Carbonyl Stretching
Double bonds in alkenes and carbonyl compounds exhibit stretching frequencies in the diagnostic region of the IR spectrum. In addition, alkenes exhibit vinylic C–H stretching and C–H out-of-plane bending absorptions that are useful for identifying substitution patterns.
Stretching frequencies are affected by several factors, such as resonance, inductive effects, ring strain, dipole moment, and hydrogen bonding. Consequently, the stretching frequency of the carbonyl double bond varies in...
Stretching frequencies are affected by several factors, such as resonance, inductive effects, ring strain, dipole moment, and hydrogen bonding. Consequently, the stretching frequency of the carbonyl double bond varies in...


