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化学大会:2019 -短程秩序,晶体成核和晶体生长液胶体悬浮液- Dieter M Herlach

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副主席德国社会石墨烯材料科学与工程化学的快速增长在过去十年和广泛的石墨烯衍生物。然而,只有两个化学衍生物是目前已知:氢化和氟化的石墨烯(graphane和fluorographene)。与石墨烯相比,这些材料表现出明显不同的属性,如更高的反应性以及物理性质之间存在较大的差异。尤其是fluorographene可以应用作为亲核取代反应的底物,大大扩展了石墨烯的化学修饰。目前,其他2 d材料化学的开始。然而,无机化学的2 d pnictogens和过渡金属dichalcogenides不是众所周知,只有几个程序已经报道。与石墨烯相比,新合成的协议已经被应用,因为这些材料的化学是非常变量。对于过渡金属dichalcogenides, M-X-C键的形成(M是一个金属,X是任何硫族化物)可以作为一个起点为探索化学和进一步derivatisation。的化学分层pnictogens是明显不同的。在这种情况下,可以应用各种反应包括亲核取代,然而,通过氧键功能pnictogen表面观察到在许多情况下。 Graphene is that the only sort of carbon (or solid material) during which every atom is out there for reaction from two sides (due to the 2D structure). Atoms at the sides of a graphene sheet have special chemical reactivity. Graphene has the very best ratio of edge atoms of any allotrope. Defects within a sheet increase its chemical reactivity. The onset temperature of reaction between the basal plane of single-layer graphene and oxygen gas is below 260 °C (530 K). Graphene combusts at 350 °C (620 K). Graphene is usually modified with oxygen- and nitrogen-containing functional groups and analyzed by infrared spectroscopy and X-ray photoelectron spectroscopy. However, determination of structures of graphene with oxygen-and nitrogen- functional groups requires the structures to be controlled. Contrary to the perfect 2D structure of graphene, chemical applications of graphene need either structural or chemical irregularities, as perfectly flat graphene is chemically inert. In other words, the definition of a perfect graphene is different in chemistry and physics. Soluble fragments of graphene are often prepared within the laboratory[ through chemical modification of graphite. First, microcrystalline graphite is treated with an acidic mixture of vitriol and aqua fortis . A series of oxidation and exfoliation steps produce small graphene plates with carboxyl groups at their edges. These are converted to acid chloride groups by treatment with thionyl chloride; next, they're converted to the corresponding graphene amide via treatment with octadecylamine. The resulting material is soluble in tetrahydrofuran, tetrachloromethane and dichloroethane. Nucleic acid analogues are compounds which are analogous (structurally similar) to present RNA and DNA, utilized in medicine and in biology research. Nucleic acids are chains of nucleotides, which are composed of three parts: a phosphate backbone, a pentose sugar, either ribose or deoxyribose, and one among four nucleobases. An analogue may have any of those altered. Typically the analogue nucleobases confer, among other things, different base pairing and base stacking properties. Examples include universal bases, which may pair with all four canonical bases, and phosphate-sugar backbone analogues like PNA, which affect the properties of the chain (PNA can even form a triple helix). macromolecule analogues also are called Xeno macromolecule and represent one among the most pillars of xenobiology, the planning of new-to-nature sorts of life supported alternative biochemistries. Artificial macromolecule s include peptide nucleic acid

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