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Octafluorocubane
Octafluorocubane or perfluorocubane is an organofluorine compound with the formula , consisting of eight carbon atoms joined into a cube, with a fluorine bonded to each carbon corner. It is a colorless, sublimable solid at room temperature. It has been of longstanding theoretical interest, but was not synthesised until 2022, when it was prepared in several steps from a cubane carboxylic ester beginning with its heptafluorination. According to X-ray crystallography, the C-C distances (1.572 Å) in octafluorocubane are identical in length to those in the parent cubane. Octafluorocubane has attracted interest from theorists because of its unusual electronic structure, which is indicated by its susceptibility to undergo reduction to a detectable anion , with the free electron trapped inside of the cube. The compound was voted "favorite molecule of 2022" by readers of ''Chemical & Engineering News ''Chemical & Engineering News'' (''C&EN'') is a weekly news magazine published by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cubane
Cubane () is a synthetic hydrocarbon compound that consists of eight carbon atoms arranged at the corners of a cube, with one hydrogen atom attached to each carbon atom. A solid crystalline substance, cubane is one of the Platonic hydrocarbons and a member of the prismanes. It was first synthesized in 1964 by Philip Eaton and Thomas Cole. Before this work, Eaton believed that cubane would be impossible to synthesize due to the "required 90 degree bond angles". The cubic shape requires the carbon atoms to adopt an unusually sharp 90° bonding angle, which would be highly strained as compared to the 109.45° angle of a tetrahedral carbon. Once formed, cubane is quite kinetically stable, due to a lack of readily available decomposition paths. It is the simplest hydrocarbon with octahedral symmetry. Having high potential energy but kinetic stability makes cubane and its derivative compounds useful for controlled energy storage. For example, octanitrocubane and heptanitrocubane have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octanitrocubane
Octanitrocubane (molecular formula: C8(NO2)8) is a high explosive that, like Trinitrotoluene, TNT, is shock-insensitive (not readily detonated by shock). The octanitrocubane molecule has the same chemical structure as cubane (C8H8) except that each of the eight hydrogen atoms is replaced by a nitro compound, nitro group (NO2). It is however not as powerful an explosive as once thought, as the high-density theoretical crystal structure has not been achieved. For this reason heptanitrocubane, the slightly less nitrated form is believed to have marginally better performance, despite having a worse oxygen balance. Octanitrocubane is thought to have 20–25% greater performance than HMX (octogen). This increase in power is due to its highly expansive breakdown into CO2 and N2, as well as to the presence of strained chemical bonds in the molecule which have stored potential energy. In addition, it produces no water vapor upon combustion, making it less visible, and both the chemical i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon–carbon Bond
A carbon–carbon bond is a covalent bond between two carbon atoms. The most common form is the single bond: a bond composed of two electrons, one from each of the two atoms. The carbon–carbon single bond is a sigma bond and is formed between one hybridized orbital from each of the carbon atoms. In ethane, the orbitals are sp3- hybridized orbitals, but single bonds formed between carbon atoms with other hybridizations do occur (e.g. sp2 to sp2). In fact, the carbon atoms in the single bond need not be of the same hybridization. Carbon atoms can also form double bonds in compounds called alkenes or triple bonds in compounds called alkynes. A double bond is formed with an sp2-hybridized orbital and a p-orbital that is not involved in the hybridization. A triple bond is formed with an sp-hybridized orbital and two p-orbitals from each atom. The use of the p-orbitals forms a pi bond. Chains and branching Carbon is one of the few elements that can form long chains of its ow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theoretical Chemistry
Theoretical chemistry is the branch of chemistry which develops theoretical generalizations that are part of the theoretical arsenal of modern chemistry: for example, the concepts of chemical bonding, chemical reaction, valence, the surface of potential energy, molecular orbitals, orbital interactions, and molecule activation. Overview Theoretical chemistry unites principles and concepts common to all branches of chemistry. Within the framework of theoretical chemistry, there is a systematization of chemical laws, principles and rules, their refinement and detailing, the construction of a hierarchy. The central place in theoretical chemistry is occupied by the doctrine of the interconnection of the structure and properties of molecular systems. It uses mathematical and physical methods to explain the structures and dynamics of chemical systems and to correlate, understand, and predict their thermodynamic and kinetic properties. In the most general sense, it is explanation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Geometry
Molecular geometry is the three-dimensional arrangement of the atoms that constitute a molecule. It includes the general shape of the molecule as well as bond lengths, bond angles, torsional angles and any other geometrical parameters that determine the position of each atom. Molecular geometry influences several properties of a substance including its reactivity, polarity, phase of matter, color, magnetism and biological activity. The angles between bonds that an atom forms depend only weakly on the rest of molecule, i.e. they can be understood as approximately local and hence transferable properties. Determination The molecular geometry can be determined by various spectroscopic methods and diffraction methods. IR, microwave and Raman spectroscopy can give information about the molecule geometry from the details of the vibrational and rotational absorbance detected by these techniques. X-ray crystallography, neutron diffraction and electron diffraction can give molecular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical & Engineering News
''Chemical & Engineering News'' (''C&EN'') is a weekly news magazine published by the American Chemical Society, providing professional and technical news and analysis in the fields of chemistry and chemical engineering.C&EN Magazine Website Chemical and Engineering News, October 12, 2009, accessed October 12, 2009 It includes information on recent news and research in these fields, career and employment information, business and industry news, government and policy news, funding in these fields, and special reports. The magazine is available to all members of the American Chemical Society. History The magazine was established in 1923,C&EN- Happy Birthday to Us, accessed O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anion
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Structure
In quantum chemistry, electronic structure is the state of motion of electrons in an electrostatic field created by stationary nuclei. The term encompasses both the wave functions of the electrons and the energies associated with them. Electronic structure is obtained by solving quantum mechanical equations for the aforementioned clamped-nuclei problem. Electronic structure problems arise from the Born–Oppenheimer approximation. Along with nuclear dynamics, the electronic structure problem is one of the two steps in studying the quantum mechanical motion of a molecular system. Except for a small number of simple problems such as hydrogen-like atoms, the solution of electronic structure problems require modern computers. Electronic structure problem is routinely solved with quantum chemistry computer programs. Electronic structure calculations rank among the most computationally intensive tasks in all scientific calculations. For this reason, quantum chemistry calculatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorination
In chemistry, halogenation is a chemical reaction that entails the introduction of one or more halogens into a compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers, drugs. This kind of conversion is in fact so common that a comprehensive overview is challenging. This article mainly deals with halogenation using elemental halogens (F2, Cl2, Br2, I2). Halides are also commonly introduced using salts of the halides and halogen acids. Many specialized reagents exist for and introducing halogens into diverse substrates, e.g. thionyl chloride. Organic chemistry Several pathways exist for the halogenation of organic compounds, including free radical halogenation, ketone halogenation, electrophilic halogenation, and halogen addition reaction. The nature of the substrate determines the pathway. The facility of halogenation is influenced by the halogen. Fluorine and chlorine are more electrophilic and are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Crystallography
X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their crystallographic disorder, and various other information. Since many materials can form crystals—such as salts, metals, minerals, semiconductors, as well as various inorganic, organic, and biological molecules—X-ray crystallography has been fundamental in the development of many scientific fields. In its first decades of use, this method determined the size of atoms, the lengths and types of chemical bonds, and the atomic-scale differences among various mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organofluorine Compound
Organofluorine chemistry describes the chemistry of the organofluorines, organic compounds that contain the carbon–fluorine bond. Organofluorine compounds find diverse applications ranging from oil and water repellents to pharmaceuticals, refrigerants, and reagents in catalysis. In addition to these applications, some organofluorine compounds are pollutants because of their contributions to ozone depletion, global warming, bioaccumulation, and toxicity. The area of organofluorine chemistry often requires special techniques associated with the handling of fluorinating agents. The carbon–fluorine bond Fluorine has several distinctive differences from all other substituents encountered in organic molecules. As a result, the physical and chemical properties of organofluorines can be distinctive in comparison to other organohalogens. # The carbon–fluorine bond is one of the strongest in organic chemistry (an average bond energy around 480 kJ/molKirsch, Peer ''Modern fluoroorga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
