Organic Chemistry
Organic Chemistry
9th Edition
ISBN: 9781305080485
Author: John E. McMurry
Publisher: Cengage Learning
Question
Book Icon
Chapter 31.6, Problem 11P
Interpretation Introduction

Interpretation:

Predict the result of the catalytic hydrogention of natural rubber and will the product obtained show syndiotactic, atactic or isotactic behaviour.

Concept introduction:

Isotactic, syndiotactic, and atactic are the stereochemical forms. The polymer having the (-R) groups on the same side of the macromolecule backbone (zigzag bone) is known as isotactic polymer. An isotactic macromolecule consists of 100% meso diads.

Syndiotactic are the macromolecules in which the (-R) groups are arranged in an alternate manner along the long chain of the polymer. Gutta-percha is also an example for Syndiotactic polymer.

In atactic form, the substituents are placed in a random manner along the long chain.

The important point to note here is that the polymer obtained from the chain-growth polymerization mechanism must have chiral carbons to possess these structures. If the polymer formed does not have chiral carbon then it cannot occur in isotactic, syndiotactic and atactic forms.

Organic Chemistry, Chapter 31.6, Problem 11P

The catalytic hydrogenation natural rubber requires the breaking of double bond and the addition of hydrogen. The double bond of alkene consists of a sigma (σ) and a pie bond (π). The carbon -carbon pie bond is relatively weak.

Therefore, it breaks and hydrogen adds to it. When the hydrogen adds, then the double bonds are replaced with the single bonds. The hydrogenation of double bond releases energy therefore, known as an exothermic reaction. The heat released is called the heat of hydrogenation.

The catalyst used for the purpose of hydrogenation can be Ra-Ni (Raney-Nickel), PtO2 (Platinum oxide), Pd-C (Palladium on carbon) etc. They can be used to enhance the rate of reaction.

Blurred answer
Students have asked these similar questions
A mixture of butyl acrylate and 4'-chloropropiophenone has been taken for proton NMR analysis. Based on this proton NMR, determine the relative percentage of each compound in the mixture
Q5: Label each chiral carbon in the following molecules as R or S. Make sure the stereocenter to which each of your R/S assignments belong is perfectly clear to the grader. (8pts) R OCH 3 CI H S 2pts for each R/S HO R H !!! I OH CI HN CI R H
Calculate the proton and carbon chemical shifts for this structure
Knowledge Booster
Background pattern image
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Principles of Modern Chemistry
Chemistry
ISBN:9781305079113
Author:David W. Oxtoby, H. Pat Gillis, Laurie J. Butler
Publisher:Cengage Learning
Text book image
Chemistry: The Molecular Science
Chemistry
ISBN:9781285199047
Author:John W. Moore, Conrad L. Stanitski
Publisher:Cengage Learning
Text book image
Introductory Chemistry: An Active Learning Approa...
Chemistry
ISBN:9781305079250
Author:Mark S. Cracolice, Ed Peters
Publisher:Cengage Learning