|
Newman Projection
A Newman projection is a drawing that helps visualize the 3-dimensional structure of a molecule. This projection most commonly sights down a carbon-carbon bond, making it a very useful way to visualize the stereochemistry of alkanes. A Newman projection visualizes the conformation of a chemical bond from front to back, with the front atom represented by the intersection of three lines (a dot) and the back atom as a circle. The front atom is called ''proximal'', while the back atom is called ''distal''. This type of representation clearly illustrates the specific dihedral angle between the proximal and distal atoms. This projection is named after American chemist Melvin Spencer Newman, who introduced it in 1952 as a partial replacement for Fischer projections, which are unable to represent conformations and thus conformers properly.Newman, MS. ''Record. Chem. Progr. (Kresge-Hooker Sci. Lib.) 1952,'' 13'', 111'' This diagram style is an alternative to a sawhorse projection, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butane
Butane () or ''n''-butane is an alkane with the formula C4H10. Butane is a gas at room temperature and atmospheric pressure. Butane is a highly flammable, colorless, easily liquefied gas that quickly vaporizes at room temperature. The name butane comes from the root but- (from butyric acid, named after the Greek word for butter) and the suffix -ane. It was discovered by the chemist Dr. Walter Snelling in 1912. It was found dissolved in crude petroleum in 1864 by Edmund Ronalds, who was the first to describe its properties. Butane is one of a group of liquefied petroleum gases (LP gases). The others include propane, propylene, butadiene, butylene, isobutylene, and mixtures thereof. Butane burns more cleanly than gasoline and coal. Density The density of butane is highly dependent on temperature and pressure in the reservoir. For example, the density of liquid phase is 571.8±1 kg/m3 (for pressures up to 2MPa and temperature 27±0.2 °C), while the density of l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereochemistry
Stereochemistry, a subdiscipline of chemistry, involves the study of the relative spatial arrangement of atoms that form the structure of molecules and their manipulation. The study of stereochemistry focuses on the relationships between stereoisomers, which by definition have the same molecular formula and sequence of bonded atoms (constitution), but differ in structural formula (the three-dimensional orientations of their atoms in space). For this reason, it is also known as 3D chemistry—the prefix "stereo-" means "three-dimensionality". Stereochemistry spans the entire spectrum of organic, inorganic, biological, physical and especially supramolecular chemistry. Stereochemistry includes methods for determining and describing these relationships; the effect on the physical or biological properties these relationships impart upon the molecules in question, and the manner in which these relationships influence the reactivity of the molecules in question (dynamic stereochemist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haworth Projection
In chemistry, a Haworth projection is a common way of writing a structural formula to represent the cyclic structure of monosaccharides with a simple three-dimensional perspective. Haworth projection approximate the shapes of the actual molecules better for furanoses -which are in reality nearly planar- than for Pyranose, pyranoses which exist in solution in the chair conformation. Organic chemistry and especially biochemistry are the areas of chemistry that use the Haworth projection the most. The Haworth projection was named after the British chemist Sir Norman Haworth. A Haworth projection has the following characteristics: * Carbon is the implicit type of atom. In the example on the right, the atoms numbered from 1 to 6 are all carbon atoms. Carbon 1 is known as the anomeric carbon. * Hydrogen atoms on carbon are implicit. In the example, atoms 1 to 6 have extra hydrogen atoms not depicted. * A thicker line indicates atoms that are closer to the observer. In the example ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newman Projection Relative Energy Diagram
Newman is a surname of English origin and may refer to many people: The surname Newman is widespread in the core Anglosphere. A * Abram Newman (1736–1799), British grocer * Adrian Newman (other), multiple people * Al Newman (born 1960), American baseball player *Alan Newman (baseball) (born 1969), American baseball player * Alec Newman (born 1974), Scottish actor *Alfred Newman (other), multiple people * Ali Newman (born 1977), better known as Brother Ali, American rapper * Alison Newman (born 1968), British actress * Allen George Newman (1875–1940), American sculptor * Alysha Newman (born 1994), Canadian pole vaulter *Amy Hauck Newman, American medicinal chemist * Andrea Newman (1938–2019), British author * Andrew Newman (other), multiple people *Angelia Thurston Newman (1837–1910), American poet and writer * Anne B. Newman (born 1955), American gerontologist * Arnold Newman (1918–2006), American photographer * Aubrey Newman (1903–1994), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newman Projection Of Cyclohexane
Newman is a surname of English origin and may refer to many people: The surname Newman is widespread in the core Anglosphere. A * Abram Newman (1736–1799), British grocer * Adrian Newman (other), multiple people * Al Newman (born 1960), American baseball player *Alan Newman (baseball) (born 1969), American baseball player * Alec Newman (born 1974), Scottish actor *Alfred Newman (other), multiple people * Ali Newman (born 1977), better known as Brother Ali, American rapper * Alison Newman (born 1968), British actress * Allen George Newman (1875–1940), American sculptor * Alysha Newman (born 1994), Canadian pole vaulter *Amy Hauck Newman, American medicinal chemist * Andrea Newman (1938–2019), British author * Andrew Newman (other), multiple people *Angelia Thurston Newman (1837–1910), American poet and writer * Anne B. Newman (born 1955), American gerontologist * Arnold Newman (1918–2006), American photographer * Aubrey Newman (1903–1994), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclohexane
Cyclohexane is a cycloalkane with the molecular formula . Cyclohexane is non-polar. Cyclohexane is a colorless, flammable liquid with a distinctive detergent-like odor, reminiscent of cleaning products (in which it is sometimes used). Cyclohexane is mainly used for the industrial production of adipic acid and caprolactam, which are precursors to nylon. Cyclohexyl () is the alkyl substituent of cyclohexane and is abbreviated Cy. Production Modern On an industrial scale, cyclohexane is produced by hydrogenation of benzene in the presence of a Raney nickel catalyst. Producers of cyclohexane account for approximately 11.4% of global demand for benzene. The reaction is highly exothermic, with ΔH(500 K) = -216.37 kJ/mol. Dehydrogenation commenced noticeably above 300 °C, reflecting the favorable entropy for dehydrogenation. : Early Unlike benzene, cyclohexane is not found in natural resources such as coal. For this reason, early investigators synthesized their cyclohexa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chair Conformation
In organic chemistry, cyclohexane conformations are any of several three-dimensional shapes adopted by molecules of cyclohexane. Because many compounds feature structurally similar six-membered rings, the structure and dynamics of cyclohexane are important prototypes of a wide range of compounds. The internal angles of a regular, flat hexagon are 120°, while the preferred angle between successive bonds in a carbon chain is about 109.5°, the tetrahedral angle (the arc cosine of −). Therefore, the cyclohexane ring tends to assume non-planar (warped) conformations, which have all angles closer to 109.5° and therefore a lower strain energy than the flat hexagonal shape. Consider the carbon atoms numbered from 1 to 6 around the ring. If we hold carbon atoms 1, 2, and 3 stationary, with the correct bond lengths and the tetrahedral angle between the two bonds, and then continue by adding carbon atoms 4, 5, and 6 with the correct bond length and the tetrahedral angle, we can vary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Molecule
A cyclic compound (or ring compound) is a term for a chemical compound, compound in the field of chemistry in which one or more series of atoms in the compound is connected to form a Ring (chemistry), ring. Rings may vary in size from three to many atoms, and include examples where all the atoms are carbon (i.e., are carbocycles), none of the atoms are carbon (inorganic cyclic compounds), or where both carbon and non-carbon atoms are present (heterocyclic compounds). Depending on the ring size, the bond order of the individual links between ring atoms, and their arrangements within the rings, carbocyclic and heterocyclic compounds may be aromatic compound, aromatic or non-aromatic; in the latter case, they may vary from being fully saturated compound, saturated to having varying numbers of multiple bonds between the ring atoms. Because of the tremendous diversity allowed, in combination, by the Valence (chemistry), valences of common atoms and their ability to form rings, the number ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natta Projection
In chemistry, the Natta projection (named for Italian chemist Giulio Natta) is a way to depict molecules with complete stereochemistry in two dimensions in a skeletal formula. In a hydrocarbon molecule with all carbon atoms making up the backbone in a tetrahedral molecular geometry, the zigzag backbone is in the paper plane (chemical bonds depicted as solid line segments) with the substituents either sticking out of the paper toward the viewer (chemical bonds depicted as solid wedges) or away from the viewer (chemical bonds depicted as dashed wedges). The Natta projection is useful for representing the tacticity of a polymer. See also * Structural formula * Wedge-and-dash notation in skeletal formulas * Haworth projection * Newman projection * Fischer projection In chemistry, the Fischer projection, devised by Emil Fischer in 1891, is a two-dimensional representation of a three-dimensional organic molecule by projection. Fischer projections were originally pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
