Contextualization
Isomerism is a phenomenon that occurs in molecules that have the same molecular formula but different structural arrangements. These molecules are called isomers and, despite being made up of the same atoms and in the same quantity, they have different chemical and physical properties.
Planar isomerism is one of the types of isomerism and consists of molecules that differ in the type of bond or in the position of atoms or atomic groups in space. Planar isomerism is classified into five types: functional isomerism, positional isomerism, chain isomerism, compensatory isomerism or tautomerism, and metamerism.
Planar isomerism is a fundamental concept in organic chemistry and is essential for understanding how small changes in molecular structure can lead to significant changes in the properties of a substance. The ability to recognize and classify planar isomers and understand the differences in the properties of isomers is an essential skill for chemists and chemical engineers.
Topical Introduction
Planar isomerism is a fascinating concept that highlights the complexity and diversity of chemistry. For example, the difference between ethanol, a substance we consume in alcoholic beverages, and dimethyl ether, a gas used in refrigeration, lies only in the way the same atoms are connected.
In addition to this important practical application, the study of planar isomerism is also essential for understanding various biological processes. Planar isomers can, in many cases, be biologically active or inactive. A famous tragedy occurred in the 1950s when the drug Thalidomide was administered to pregnant women to combat nausea. The drug had an isomer that caused deformities in fetuses, resulting in serious consequences.
In summary, mastering the concept of planar isomerism is not only relevant for understanding chemistry as a science but is also crucial for practical applications that have direct implications in everyday life and human health.
Practical Activity: Deciphering Planar Isomers
Project Objective
The objective of this project is to allow students the opportunity to investigate on their own the different types of planar isomerism, learn to recognize and classify isomers, and verify the number of possible isomers for different compounds.
Project Description
The project will be divided into three main parts. First, the research and theoretical study of planar isomerism. Second, the representation and classification of isomers for different compounds. Finally, the writing of a report detailing the results of the investigation and the relevance of isomerism in the real world.
Required Materials
- Computer with internet access for research
- 3D modeling software for chemistry or free online tools that allow this
- Sheets of paper, pencils, and writing material
- At least one chemistry textbook for reference
Activity Steps
Part 1: Theoretical Research
- Form groups of 3 to 5 students.
- Each group should research and study planar isomerism, focusing on understanding the five types of isomerism - functional, positional, chain, compensatory (tautomerism), and metamerism. We recommend using the material provided in the resources section, in addition to consulting other materials that can be found on the internet or in chemistry textbooks.
- Each group should prepare a presentation on what they have learned, including definitions, examples, and an explanation of how to identify each type of planar isomerism.
Part 2: Representation and Classification of Isomers
- After the research and theoretical study, the groups will choose two organic compounds of their choice.
- Using 3D modeling software for chemistry, students will create as many isomers as possible for the chosen compounds, always observing the octet rule.
- Each group will classify the created isomers according to the type of planar isomerism (functional, positional, chain, compensatory, or metamerism).
- In a presentation, each group must explain the isomers that were created, the type of isomerism each one presents, and how they arrived at this conclusion.
Part 3: Writing the Report
- Each group will write a report containing the following parts: Introduction, Development, and Conclusions. The Introduction should contextualize the theme, its relevance in the real world, and the objective of this project. The Development, in turn, should explain the theory behind planar isomerism, detail the activity, indicate the methodology used, present the results obtained, and discuss these results. The Conclusions should summarize the main points, explain the learnings obtained, and draw conclusions about the project. Finally, students should also include a Bibliography section, indicating the sources of information used during the project.
Project Deliverables
At the end of the project, each group must deliver:
- Two presentations: one on the theory of planar isomerism and another on the created and classified isomers.
- A detailed report of the entire process, from theoretical research to the classification of isomers, including the conclusions obtained in the project.
Each stage of the project is crucial for learning and understanding planar isomerism. In addition, group work, task distribution, and the development of research, presentation, and scientific writing skills are fundamental aspects of the project.
Students should focus on clearly highlighting in their report the transition between the theoretical part of planar isomerism and the practical part of the project, the creation and classification of isomers. The report should also clearly explain the choices made by the group during the project development.
