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Alcanos con par de C tienen p. For butane there will be two different staggered conformations: Some groups are so bulky that they are extremely conrormacional in axial positions.
Conformations of Cyclobutane Caption: Conformational Analysis of Butane Caption: The bond angles are Any carbon with four sigma bonds has an sp3 hybridization. All the carbon-carbon bonds are eclipsed, generating torsional strain that contributes to the total ring strain.
Totally Eclipsed Conformation of Butane Caption: Butano tiene 2 conformaciones alternadas diferentes: Some conformations can be more stable than others.
The unfavorable conformation has both methyl groups in axial positions, with a 1,3-diaxial interaction between them. Torsional energy of propane.
Estructura y Estereoquímica de Alcanos – ppt video online descargar
All the C-H bonds are staggered in the chair conformation. Their physical properties resemble those of alkanes. Among the staggered conformations, the anti is lower in energy because it has the electron clouds of the methyl groups as far apart as possible. Pure conformers cannot be isolated in most cases, because the molecules are constantly rotating through all the possible conformations.
The chair conformation is most stable, followed by the twist boat. Longer chained alkanes have greater surface area and can have more surface contact and more induced dipoles than branched alkanes with smaller surface areas.
Numbering from left to right gives the first branch on C2; numbering from right to left gives the first branch on C3, so we number from left to right.
Some common alkyl groups and their names. To convert between these two conformations, the molecule must pass through the unstable half-chair conformation. To make this website work, we log user data and share it with processors. Ethane has two sp3 carbons. Sobre conformacuonal proyecto SlidePlayer Condiciones de uso. Alcohols are compounds whose molecules have a hydroxyl. The following figure shows the severe izomeria interactions in a chair conformation with a t-butyl group axial.
Newman Projections of Butane Caption: Methane is perfectly tetrahedral, with the The molecular formula of alkanes is CnH2n, two hydrogen less than an open chain alkane.
This puckered conformation reduces the eclipsing of adjacent CH2 groups. Conformational energy of cyclohexane. When a bond of propane rotates, the torsional energy varies much like it does in ethane, but with 0. In solids, the packing of the molecules into a three dimensional structure affects the melting point.
The torsional energy of ethane is lowest in the staggered conformation. Two chair conformations are possible for cis-1,3-dimethylcyclohexane.
Estructura y Estereoquímica de Alcanos
La eclipsada es 3. Angle strain in cyclopropane. Looking down the C1-C2 bond of the equatorial conformation, we find that the methyl group is anti to C3.
Cyclohexanes with tertiary-butyl substituents show that an axial t-butyl group is severely hindered. Since the methyl group occupies more space than a hydrogen, the torsional strain will be 0. Los botones se encuentran debajo.
Regardless of the conformxcional groups present, the most stable conformation has conformacionap t-butyl group in an equatorial position. The eclipsed conformations are higher in energy than the staggered conformations of butane, especially the totally eclipsed conformation.
An equatorial methyl group will be anti to the C3. Same Length Chains Caption: Viewed from the Newman projection, the chair conformation has no eclipsing of the carbon-carbon bonds.