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Differentiating complete structural formulas and condensed structural formulas using examples

Draw complete structural formulas and  condensed structural formulas for

        a) three compounds of formula C3H8O

        b) five compounds of formula C3H6O

The condensed structural formula disguises the molecule's true vastness by revealing only the number of atoms present. What remains hidden from sight are the bond connections, the bond angles, and their three-dimensional arrangements, so what we observe is just the molecule's literal condensed form.

Some examples below of a few molecules can illustrate how the condensed structural formula compares with elaborate, complete dash structures. 

 

In the chapter Drawing Organic Structures, we discussed the limitations of interpreting the molecule using molecular formulas. A molecular formula may conceal several variations crucial to organic chemistry. The variations might differ in functional groups and their positions in their molecule to create functional or positional isomers. Or even the neighbors next to a functional group might change, generating metamers. All this may impact how such molecules undergo chemical reactions, making the study of constitutional isomers an important part of organic chemistry. You don't want to assume a molecule with molecular formula C3H8O is only an alcohol. It may be an ether, too. 

Some of the constitutional isomers possible with a given molecular formula are covered in the examples.

a) Three constitutional isomers are possible with C3H8O

 

 

b) Nine constitutional isomers are possible with C3H6O

 

 

Step-by-step tutorials on how to draw various constitutional isomers are covered in the course - Drawing Organic Structures, part of Introductory Organic Chemistry. 

In molecules that are not saturated, that is, do not follow the CnH2n+2 rule, the chances of finding a double bond or an equivalent are high. The double bond equivalent (DBE) section covers how to calculate and interpret a DBE value. 

 

Drawing Organic Structures
Organic Chemistry - Drawing Structures, Concepts, and Examples

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Common Types of Reactions

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Drawing Organic Structures

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Functional Groups in Organic Chemistry

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Structural Isomerism

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Fundamentals of Organic Reactions

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Reactive Intermediates

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Stereoisomerism - Conformation and Configurational Isomerism

  • Conformations in Organic Chemistry - An Introduction
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  • Nomenclature related to sp3-sp3 and sp3-sp2 bond rotations
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  • E/Z Nomenclature in Substituted Alkenes
     

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