Determine the relationship between each of the pairs of the following compounds. Are they structural isomers (different molecules), conformational isomers (the same molecule), or not related?
(d)

Question

Determine the relationship between each of the pairs of the following compounds. Are they structural isomers (different molecules), conformational isomers (the same molecule), or not related?

(d)

Accepted Answer

Welcome back everyone. For the pair of organic compounds below determine whether they are structural isomers, which means different molecules, confirmational isomers or the same molecule stereo isomers, same connectivity, but different spatial arrangement of atoms or unrelated. Whenever we have a problem of that kind, we simply want to identify the number of carbon atoms in a structure so that we can define the molecular formula for each compound. The first compound has 123456 and seven carbons. So we can state C seven for the second one, we have 123, 45 in six carbon atoms. And then there is an additional seventh carbon. So we again begin with C seven. Each structure is an alkane. We can see that those are saturated hydrocarbons. So based on the general formula C and H two N plus two, we can also state that there would be 16 hydrogens for each structure. So we don't need to count them individually. Of course, we can do that, but we want to save time, right? If they have the same molecular formula, they cannot be unrelated, they also cannot be stereo isomers because stereo isomers would indicate wedges and dashes and chiral centers. In this case, we can only see solid line bonds. Now, can they be confirmational isomers? Well, whenever we went to identify confirmational isomers, we also have to ask ourselves, can they actually be structural isomers? And structural isomers simply means that we have a different connectivity of atoms in a molecule, which essentially represents the same molecular formula into possibly different cases. The easiest way is to generally identify the parent, which is the longest continuous carbon chain. We can notice that the first structure has a five membered parent, right, which is simply pens with two methyl substituents. The second structure however, has a longer parent. It has a six member chain which is hexane with a methyl group. So they are actually structural or basically constitutional isomers, confirmational isomers, those will have the same parent and the same connectivity but essentially a different spatial arrangement of atoms based on the free bond rotation around the carbon carbon bonds, right. So these are actually structural isomers because they represent the same molecular formula, but a different connectivity of atoms which is basically seen from a different length of the parent chains. Five verses six. Thank you for watching.

Determine the relationship between each of the pairs of the following compounds. Are they structural isomers (different molecules), conformational isomers (the same molecule), or not related?
(d)

Verified video answer for a similar problem:

Key Concepts

Structural Isomers

Conformational Isomers

Isomerism

Determine the relationship between each of the pairs of the following compounds. Are they structural isomers (different molecules), conformational isomers (the same molecule), or not related?(d)

Verified video answer for a similar problem:

Key Concepts

Structural Isomers

Conformational Isomers

Isomerism

Determine the relationship between each of the pairs of the following compounds. Are they structural isomers (different molecules), conformational isomers (the same molecule), or not related?
(d)