The lowest energy conformation of ethane, shown in the figure above, is called the ‘staggered’ conformation, in which all of the C-H bonds on the front carbon are positioned at dihedral angles of 60°relative to the C-H bonds on the back carbon. The maximum energies are the absolute maximum; the minimum energies are the absolute minimum, and there are no intermediate maxima or minima. Holding a model of ethane (or two) in your hand would really help you here. In ethane (CH 3 CH 3), for example, both carbons are approximately tetrahedral.Thus, there are two limiting structures— staggered ethane, in which the carbon-hydrogen bonds are as far apart as possible, and eclipsed ethane, in which the bonds are as close as possible. Eclipsed Ethane (CH 3 CH 3, with H - lined up) & Staggered Ethane (CH 3 CH 3, with H - not lined up) top. The minimum conformation of ethane corresponds to structure 2 in which all hydrogen atoms are staggered so as to reduce steric interactions as much as possible. The reason for the relative stability of the staggered conformation has been debated for years. One theory is that the staggered form is more stable because there is a favorable inter-action between the bonding and antibonding molecular orbitals associated with the CLH Ethane is the most important gaseous fuel. But this way you can see the front carbon's hydrogens are staggered relative to the back ones. Ethane (/ ˈ ɛ θ eɪ n / or / ˈ iː θ eɪ n /) is an organic chemical compound with chemical formula C 2 H 6.At standard temperature and pressure, ethane is a colorless, odorless gas.Like many hydrocarbons, ethane is isolated on an industrial scale from natural gas and as a petrochemical by-product of petroleum refining.Its chief use is as feedstock for ethylene production. Problem: The eclipsed and staggered forms of ethane are said to differ in: a. structureb. Holding a model of ethane (or two) in your hand would really help you here. It defines the shapeof ethane molecules. cubic/hexagonal boron nitride, and diamond/lonsdaleite. Ch 2 Ethane 5(10) Fig. Because ethane is composed of two carbons there are only hydrogen atoms on each carbon, so that the molecule is symmetrical. These two conformations are known to be the most opposite the most extreme conformations of ethane. The principal rotation axis has the highest "order" -- … Currently, there is an oversupply of ethane that has kept the ethane price relatively low, hovering at or below the price of natural gas. In this conformation, the distance between the bonds (and the electrons in them) is maximized. Ethane in gas form is staggered, as demonstrated by Raman spectroscopy.4 No second harmonic generation was observed, owing to the presence of an inversion centre in the staggered form.5 One would expect it to settle down in the eclipsed form with the Câ C axis parallel to the surface and with four rather than three â Câ H legsâ down. The dihedral angle between two C-H bonds in the staggered conformation of ethane is (a) 60 ° ° (b) 180 ° ° (c) 0 ° ° (d) 120 ° ° Q 30: (1) Ethane (/ ˈ ɛ θ eɪ n / or / ˈ iː θ eɪ n /) is an organic chemical compound with chemical formula C 2 H 6.At standard temperature and pressure, ethane is a colorless, odorless gas.Like many hydrocarbons, ethane is isolated on an industrial scale from natural gas and as a petrochemical by-product of petroleum refining.Its chief use is as feedstock for ethylene production. When we look straight on, the front carbon, they're obviously blocking each other. For some molecules such as those of n-butane, there can be special versions of staggered conformations called gauche and anti; see first Newman projection diagram in Conformational isomerism. What is Eclipsed Conformation Eclipsed conformation is the arrangement of atoms or groups of atoms in a molecule resulting, in a 0 o dihedral angle. A sawhorse projection is a view of a molecule down a particular carbon-carbon bond. When we notice a structure of ethane we will notice a single C-C bond and every atom tends to be bonded to three atoms of hydrogen per bond. Below are two Sawhorse Projections of ethane. If we consider ethane as a reference molecule for our conformational analysis and check their Newman projection we can easily see the two extremes. Ethane is a saturated hydrocarbon found in gaseous state. Holding a model of ethane (or two) in your hand would really help you here. Comparison of the Numbers and Kinds of Symmetry Elements in Eclipsed and Staggered Ethane. We're just looking straight on to this ethane molecule. And when you look at it like this, it is more clear that it's staggered. In this conformation, the distance between the bonds (and the electrons in them) is maximized. Learn how and when to remove this template message, https://en.wikipedia.org/w/index.php?title=Staggered_conformation&oldid=992696992, Wikipedia articles needing context from March 2011, Wikipedia introduction cleanup from March 2011, Creative Commons Attribution-ShareAlike License, This page was last edited on 6 December 2020, at 17:04. axis has no other axis collinear with it. The potential energy is minimum in staggered conformation (more stable) while it is maximum at eclipse conformation (less stable). In organic chemistry, a staggered conformation is a chemical conformation of an ethane-like moiety abcX–Ydef in which the substituents a, b, and c are at the maximum distance from d, e, and f. This requires the torsion angles to be 60°.[1]. The structure on the left is staggered, and the structure … A horizontal mirror is defined as being perpendicular to the principal axis. The anti conformation is staggered conformation because it produces by rotating eclipsed conformation four times by 60°. Click on the symmetry element to go to explainations. Natural gas components of ethane and heavier hydrocarbons are quite easily separated from the gas stream and liquefied under moderate pressure. Using Sawhorse projection, the three-dimensional structure of the eclipsed and staggered conformations can be easily visualized. Due to this, it is not possible to separate different conformation isomers of ethane. To convert the wedge-dash structure to a sawhorse projection, we must look at the molecule from one end. Inversion Center -- located at center of molecule (0, 0, 0). Click on the symmetry element to go to explainations. Get detailed, expert explanations on sp3 hybrid orbitals and the structure of ethane that can improve … Eclipsed bonds are characterized by a torsion angle of 0° (syn). The lowest energy conformation of ethane, shown in the figure above, is called the ‘staggered’ conformation, in which all of the C-H bonds on the front carbon are positioned at dihedral angles of 60°relative to the C-H bonds on the back carbon. Crystal structures: The staggered/eclipsed configurations distinguish different crystalline structures of e.g. As a … Groups connected to both the front and back carbons are drawn using sticks at 120° angles. The staggered conformation with the dihedral angle of 60o, where the H atoms on the 1st carbon are at … mole of staggered ethane into one mole of eclipsed ethane. Ethane is the second simplest alkane followed by methane. Other names – Methyl methane, Bimethyl, Dimethyl, Et… Let's start with a wedge-dash view of the staggered conformation of ethane. The Newman projection corresponding to forms A-D is shown below (5-8).In the case of ethane, the staggered and eclipsed conformations can sufficiently describe the features of its conformational analysis. Ethane – C 2 H 6. Ethane, a key feedstock for petrochemical manufacturing, is traditionally produced by recovering the ethane content from natural gas as the Y-grade NGL. conformation FREE Expert Solution Show answer 90% (214 ratings) It is prepared by laboratory method using sodium propionate. These are known as Sawhorse projection and Newman projection. As complexity increases, isomerism induced by rotations about bonds becomes a bigger factor. Lewis Structure: Analysis of Energies: Ethane, with only carbon-hydrogen bonds interacting with each other, displays simple sine curves when the torsion, 1-4 Van der Waals, and total energies are graphed. configurationc. In organic chemistry, a staggered conformation is a chemical conformation of an ethane-like moiety abcX–Ydef in which the substituents a, b, and c are at the maximum distance from d, e, and f. This requires the torsion angles to be 60°. These two structures are certainly not the same. It contains 2 carbon atoms and 6 hydrogen atoms. So the formula for ethane is C2H6. constitutiond. molecular formulae. …there are two limiting structures—staggered ethane, in which the carbon-hydrogen bonds are as far apart as possible, and eclipsed ethane, in which the bonds are as close as possible. Hence, the staggered form of ethane is more stable than its eclipsed form.The energy difference between the staggered and eclipsed conformation is 12.55 KJ mol −1. In the staggered conformation, all of the C-H bonds on the front carbon are positioned at an angle of 60° relative to the C-H bonds on the back carbon. Staggered conformation is a chemical conformation of an ethane-like molecule (CH 3 -CH 3 =abcX–Ydef) in which the substituents a, b, and c are attached at the maximum distance from d, e, and f. In this case, the torsion angle is 60° and the conformational energy is minimum. Each H-C-C-H unit in ethane is characterized by a torsion angle. Such a conformation exists in any open chain single chemical bond connecting two sp3-hybridised atoms, and is normally a conformational energy minimum. 2.4 The dihedral angle-potential energy diagram of butane. Click on the symmetry element to go to explainations. That is due to the minimized repulsion between bond electron pairs of the C-H bonds. Perhaps the best view in which to see the difference is a… 99% ethane molecules have staggered conformation. Sawhorse Projections can also be drawn so that the groups on the front carbon are staggered (60 degrees apart) or eclipsed (directly overlapping) with the groups on the back carbon. edward_qiao_3I wrote:To add on to this, you can tell mostly because the Newman projection gives you the 2-D image looking along the C-C bond - think of it as facing C1 head-on so that C2 is perfectly behind it.Staggered and eclipsed just refer to the positions of the hydrogens in this radial image - staggered means that the angle between a hydrogen on C1 and a hydrogen on C2 is 60 … The lowest energy conformation of ethane, shown in the figure above, is called the ‘staggered’ conformation. Learn all about sp3 hybrid orbitals and the structure of ethane. In this structure, two methyl groups are positioned in such a way that they are opposite to each other making a dihedral angle of between two methyl groups. 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