Search results
Results from the WOW.Com Content Network
Rotation about single bond of butane to interconvert one conformation to another. The gauche conformation on the right is a conformer, while the eclipsed conformation on the left is a transition state between conformers. Above: Newman projection; below: depiction of spatial orientation.
In organic chemistry, syn-and anti-addition are different ways in which substituent molecules can be added to an alkene (R 2 C=CR 2) or alkyne (RC≡CR).The concepts of syn and anti addition are used to characterize the different reactions of organic chemistry by reflecting the stereochemistry of the products in a reaction.
In chemistry, absolute configuration refers to the spatial arrangement of atoms within a molecular entity (or group) that is chiral, and its resultant stereochemical description. [1] Absolute configuration is typically relevant in organic molecules where carbon is bonded to four different substituents .
Figure 3: Representation of a strictly anti-coplanar conformation. A, B, C, and D are in the same plane and the dihedral angle between A–B and C–D is 180°. Figure 4: Newman projection showing A and D anti-periplanar. Figure 5: Sawhorse projection of 2-chloro-2,3-dimethylbutane showing Cl and H anti-periplanar.
In organic chemistry, a ring flip (also known as a ring inversion or ring reversal) is the interconversion of cyclic conformers that have equivalent ring shapes (e.g., from a chair conformer to another chair conformer) that results in the exchange of nonequivalent substituent positions. [1]
The gauche effect is very sensitive to solvent effects, due to the large difference in polarity between the two conformers.For example, 2,3-dinitro-2,3-dimethylbutane, which in the solid state exists only in the gauche conformation, prefers the gauche conformer in benzene solution by a ratio of 79:21, but in carbon tetrachloride, it prefers the anti conformer by a ratio of 58:42. [9]
The chair conformation is the most stable conformer. At 298 K (25 °C), 99.99% of all molecules in a cyclohexane solution adopt this conformation. The C–C ring of the chair conformation has the same shape as the 6-membered rings in the diamond cubic lattice. [7]: 16 This can be modeled as follows.
The conformational inversion of substituted cyclohexanes is a very rapid process at room temperature, with a half-life of 0.00001 seconds. [ 14 ] There are some molecules that can be isolated in several conformations, due to the large energy barriers between different conformations. 2,2',6,6'-Tetrasubstituted biphenyls can fit into this latter ...