Staggered conformation and eclipsed conformation are two types of Newman projections that show the spatial arrangement of atoms. The main difference between staggered conformation and eclipsed conformation is that staggered conformation has a lower potential energy whereas eclipsed conformation has the maximum potential energy.
What is staggered and eclipsed conformation in organic chemistry?
The two terms, Staggered and eclipsed conformation (two main branches of the Newmann projections) are used in Organic Chemistry to explain the arrangement of atoms in some organic molecules. In terms of stability, staggered conformation is more stable than eclipsed formation.
What is an eclipsed conformation?
The eclipsed conformation is so unstable that it only exists as a transition state between staggered conformations. It only exists for a short time as the molecule rotates from one staggered state to another. The following diagram is a summary of the energy of all the possible conformations:
What is an example of staggered conformation?
An example of a staggered conformation looks like this: There are 2 other terms used to describe staggered conformations: The most stable form of the Newman projection is the anti conformation.
What are the eclipsed and staggered conformations of butane?
Such degeneracy is broken in butane, which has two different eclipsed conformations and two different staggered conformations. These conformations differ by the relative positions of the two methyl substituents. In the most stable conformation, the two methyl groups lie as far apart from each other as possible with a dihedral angle of 180 degrees.
What is meant by staggered conformation?
Staggered (staggered conformation): Two atoms and/or groups whose dihedral angle is 60o, or close to 60o. In other words, their bonds to the axis of rotation are not aligned. Also a conformation which contains this arrangement.
How do you know if its staggered or eclipsed?
The main difference between staggered conformation and eclipsed conformation is that staggered conformation has a lower potential energy whereas eclipsed conformation has the maximum potential energy.
What is a eclipsed conformation in chemistry?
Eclipsed (eclipsed conformation): Two atoms and/or groups whose dihedral angle is 0o. In other words, their bonds to the axis of rotation are aligned. Also refers to a conformation which contains this arrangement.
What are staggered and eclipsed conformations of alkanes?
The dihedral angle between the two concerned hydrogen atoms here is 60°. This conformation of alkanes also has a name, staggered conformation. In ethane conformations, the eclipsed conformation is unstable. The two hydrogen atoms that line up together have unfavourable interactions, they repel each other.
How will you differentiate between staggered and eclipsed conformation of ethane?
The staggered conformation of ethane is more stable than eclipsed conformation. Since eclipsed conformation has a greater potential energy due to torsional strain, it is less stable than the staggered conformation.
Which is more stable eclipsed or staggered and why?
…with respect to the other—the eclipsed conformation is the least stable, and the staggered conformation is the most stable. The eclipsed conformation is said to suffer torsional strain because of repulsive forces between electron pairs in the C―H bonds of adjacent carbons.
Is staggered or eclipsed more energy?
The energy of the eclipsed conformation is approximately 3 kcal/mol higher than that of the staggered conformation. Another 60°rotation returns the molecule to a second eclipsed conformation.
What are three types of conformational isomers?
A: antiperiplanar, anti or trans. B: synclinal or gauche. C: anticlinal or eclipsed. D: synperiplanar or cis.
What are conformations in organic chemistry?
Conformation: The shapes that a molecule can adopt due to rotation around one or more single bonds. Eclipsed. Staggered. Conformations of ethane.
What is the difference between isomers and conformers?
Solution : Isomers cannot be changed into one another, these are not interconvertible. On the other hand, conformers are interconvertible.
What are the types of conformations?
Predominantly, these can be broadly classified into two different cases:Eclipse conformation. Conformation in which hydrogen atoms are attached to two carbons stay nearest to each other as possible is known as eclipsed.Staggered conformation.
What is the energy difference between the eclipsed conformations?
The energy of the eclipsed conformation is approximately 3 kcal/mol (12 kJ/mol) higher than that of the staggered conformation. Torsional strain (or eclipsing strain) is the name give to the energy difference caused by the increased electrostatic repulsion of eclipsing bonds.
Does eclipsed or staggered have more energy?
The energy of the eclipsed conformation is approximately 3 kcal/mol higher than that of the staggered conformation. Another 60°rotation returns the molecule to a second eclipsed conformation.
How do I convert staggered to eclipse?
To convert between eclipsed and staggered conformations (or vice versa), one carbon, with all of its substituents, is rotated 60 degrees. You can imagine the projection like a combination lock. The back carbon is like the lock itself and the front carbon like the knob you turn to enter your combination.
What is staggered form of ethane?
The staggered form of ethane has minimum repulsive forces, minimum energy, the least torsional strain and maximum stability because the electron cloud of carbon hydrogen bond are maximum apart.
Why is staggered conformation more stable?
Staggered conformation of ethane is more stable than the eclipsed conformation because in staggered form the electron clouds of carbon – hydrogen bonds are as far apart as possible. So there are minimum repulsive forces.
Why is the eclipsed conformation less stable?
Since there are no spaces between the atoms or groups of atoms in the eclipsed conformation, there is a high repulsion between the bond electron pairs. Thus, eclipsed conformation is less stable. In this arrangement, the strain between atoms is very high. Since this conformation is unstable, it indicates that this molecule has a high potential ...
Why is the staggered conformation the most stable?
There are even spaces between atoms in the staggered conformation so that the repulsion between atoms is minimized. Therefore, it is the most stable conformation. This indicates that the molecules in their staggered conformation have a low potential energy when compared to other possible conformations.
Which is the most stable conformation of ethane?
The above image shows the staggered conformation of ethane. Staggered conformation is the most stable among other possible conformations for ethane. That is due to the minimized repulsion between bond electron pairs of the C-H bonds.
What is the arrangement of atoms or groups of atoms in a molecule?
Staggered conformation is the arrangement of atoms or groups of atoms in a molecule, resulting in a 60 o dihedral angle. This conformation gives the molecule a low strain because the atoms or groups of atoms are positioned in such a way that the repulsions between the bond electron pairs are minimized. There are even spaces between atoms in the sta ggered conformation so that the repulsion between atoms is minimized. Therefore, it is the most stable conformation . This indicates that the molecules in their sta ggered conformation have a low potential energy when compared to other possible conformations.
1. Recap: The Tetrahedral Structure of Methane (CH4)
In a previous post we discussed how we know that methane CH4 is tetrahedral ( See: How Do We Know That Methane Is Tetrahedral ), as this shape maximizes the distance between the repulsive bonding electron pairs.
2. The Three-Dimensional Structure of Ethane (C2H6)
So if that’s the structure of methane (CH4) then what is the structure of the next hydrocarbon up, ethane (C2H6) ?
3. Rotations Along Carbon-Carbon Bonds: Conformational Isomers Of Ethane
The addition of the new carbon-carbon bond in ethane brings about some additional complications that are part of what makes organic chemistry interesting (or as some of us like to say, “fun”).
4. Eclipsed And Staggered Conformations Of Ethane
In case it’s still not obvious to you how these two forms of ethane are subtly different, it might help to look at it end-on.
5. Visualizing Staggered vs Eclipsed Conformations of Ethane: Introducing The Newman Projection
As you probably noticed, the “end-on” views of the staggered and eclipsed conformations in the short videos above were drawn in a quirky way. What’s the deal with those circles?
8. Torsional Strain
So are the two important conformational isomers of ethane equivalent in energy?
9. What About Propane and Butane?
They can be drawn from a variety of perspectives. Changing the perspective does not change the molecule, but it can help to visualize certain characteristics.
What is a staggered conformation?
Staggered conformations are a fairly stable conformation as the atoms are spread apart to minimize steric hindrance. An example of a staggered conformation looks like this: There are 2 other terms used to describe staggered conformations: Anti conformation. Gauche conformation.
What happens when two carbons of focus are eclipsed?
In the eclipsed conformation, groups coming off the two carbons of focus in the Newman projection interact with and repel each other, creating steric hindrance as they directly overlap with one another. Larger substituents – such as alkyl groups, halogens, and oxygen-containing groups, for example – create more hindrance. The larger the substituents, the more hindrance present.
How far apart are the two largest substituents on each carbon of the Newman projection?
In this form, the largest substituent coming off the front carbon is exactly 180 o degrees away from the largest substituent on the back carbon; therefore, the two largest substituents on each carbon of the Newman projection are as far apart from one another as possible, leading to the least possible steric hindrance.
What are the two subgroups of Newman projections?
The overlap, and the energy difference associated with this overlap, leads to two energetic subgroups of Newman projections: eclipsed and staggered . Eclipsed conformations result in more steric hindrance between two atoms than staggered conformations because of how close the atoms can get to one another. Eclipsed conformations are therefore less ...
What shape does the front carbon of a Newman projection have?
When drawing Newman projections, the front carbon is indicated by the central point of from “Y-like” shape, and the back carbon is not explicitly shown, although it is assumed to be right behind the front carbon.
Is fluorine a cyclic substituent?
Fluorine is also a large atom but not as large as the cyclic substituent (which is labeled as C 6 H 8 ). The eclipsed conformation is so unstable that it only exists as a transition state between staggered conformations. It only exists for a short time as the molecule rotates from one staggered state to another.
Which is more stable, the eclipsed or the staggered form?
They have less energy because repulsion is less among the atoms or groups of atoms. This is more stable than the eclipsed form. In staggered form there are two types: Anti and gauche staggered.
Which is more stable, staggered or eclipse?
Since there are fewer repulsive forces and less energy due to the large division between the electron clouds of C-H bonds, the staggered conformation is more stable than the eclipse conformation.
What is Conformation?
In alkanes, the electron distribution in the sigma molecular orbital is symmetrical around the C-C bond's internuclear axis. As a result, free rotation about the C-C single bond is possible. Different spatial configurations of carbon atoms in space are seen as a result of this rotation, and these spatial arrangements can transform into one another.
Why do conformers (I) and (II) coexist?
Therefore, the conformers (I) and (II) coexist together because their energies are very close. But the polar solvent molecules surround the Cl atoms by dipole-dipole attraction and relieve the dipole-dipole repulsion between Cl atoms themselves. Hence, the lower energy (e, e) conformer (I) predominates in polar solvents.
How many conformations does ethane have?
They rotate in the compound. For example: In ethane the centre atom is carbon and by the carbon one methane and three hydrogen atoms are attached. So ethane generally shows two conformations: one is staggered and the second is eclipsed.
Why does conformation differ for every given molecule?
Conformation differs for every given molecule because there can be multiple conformations in which a single molecule exists.
How are conformers represented?
Representation of Conformations: Conformers are represented in two simple ways- Sawhorse representation and Newman projection.
What is the most stable conformation?
In the most stable conformation, the two methyl groups lie as far apart from each other as possible with a dihedral angle of 180 degrees. This particular staggered conformation is called anti. The other staggered conformation has a Me-Me dihedral angle of 60 degrees and is called gauche. The gauche form is less stable than the anti form by 0.9 kcal/mol due to steric hindrance between the two methyl groups. Such an interaction is often referred to as a gauche-butane interaction because butane is the first alkane discovered to exhibit such an effect.
Which alkanes have conformational preferences similar to ethane and butane?
Pentane and higher alkanes have conformational preferences similar to ethane and butane. Each dihedral angle tries to adopt a staggered conformation and each internal C-C bond attempts to take on an anti conformation to minimize the potential energy of the molecule. The most stable conformation of any unbranched alkane follows these rules to take on zigzag shapes:
