October 17, 2019, 02:16:17 PM
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Topic: How many isomers are in this molecule?  (Read 257 times)

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Offline INeedSerotonin

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How many isomers are in this molecule?
« on: October 12, 2019, 07:16:58 PM »


Hello

I have this exercise in which I have to say how many isomers are there in this molecule (if the aromatic ring cannot be removed). The answer is 4, but I'm unsure as to how can someone find this.

Could you guys give me any tips here?

Thanks

Offline AWK

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Re: How many isomers are in this molecule?
« Reply #1 on: October 13, 2019, 01:39:05 AM »
1. Swap the methyl group with the amino group.
2 Move the methyl group to different positions of the phenyl ring.

I can see 5 isomers.
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Offline sjb

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Re: How many isomers are in this molecule?
« Reply #2 on: October 13, 2019, 05:26:47 AM »
Depending on how you define "the aromatic ring can not be removed" there are possibly more than 5. Not sure that would be covered at school level though.

Offline INeedSerotonin

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Re: How many isomers are in this molecule?
« Reply #3 on: October 13, 2019, 08:28:55 AM »
1. Swap the methyl group with the amino group.
2 Move the methyl group to different positions of the phenyl ring.

I can see 5 isomers.

I can see only four isomers

1) The original molecule (CH3 - NH - benzene)
2) NH2 - ortho-methyl-benzene
3) NH2 - meta-methyl-benzene
4) NH2 - para-methyl-benzene

What is the fifth one? I cannot find it  ??? ??? :(

Depending on how you define "the aromatic ring can not be removed" there are possibly more than 5. Not sure that would be covered at school level though.

What is the other possible interpretation? I'm still on High School level of chemistry.
« Last Edit: October 13, 2019, 08:53:28 AM by INeedSerotonin »

Offline AWK

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Re: How many isomers are in this molecule?
« Reply #4 on: October 13, 2019, 09:29:31 AM »
H2NCH2-C6H5

o-, m-, p- toluidine, benzylamine
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Offline INeedSerotonin

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Re: How many isomers are in this molecule?
« Reply #5 on: October 13, 2019, 10:02:45 AM »
H2NCH2-C6H5

o-, m-, p- toluidine, benzylamine

Thank you!

Could I say that there are 6 isomers in total, counting the original molecule too?

Offline AWK

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Re: How many isomers are in this molecule?
« Reply #6 on: October 13, 2019, 10:19:41 AM »
No, together with N-methyl aniline you have 5 isomers of benzene serie.
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Offline INeedSerotonin

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Re: How many isomers are in this molecule?
« Reply #7 on: October 13, 2019, 10:23:48 AM »
No, together with N-methyl aniline you have 5 isomers of benzene serie.

Ok! Thanks!  ;)

Offline chenbeier

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Re: How many isomers are in this molecule?
« Reply #8 on: October 13, 2019, 11:03:18 AM »
You can also move the nitrogen into the aromatic ring, you can have o-,m-, and p- Ethylpyridine and 2,3-, 2,4-, 2,5-, 2,6- ,3,4- and 3,5-Dimethyl pyridine  So 14 Isomeres in total.

Offline sjb

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Re: How many isomers are in this molecule?
« Reply #9 on: October 13, 2019, 11:04:59 AM »
Depending on how you define "the aromatic ring can not be removed" there are possibly more than 5. Not sure that would be covered at school level though.

What is the other possible interpretation? I'm still on High School level of chemistry.

Consider compounds like CCc1cccnc1 or even C=CCC1=CC=CN1

Offline sjb

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Re: How many isomers are in this molecule?
« Reply #10 on: October 13, 2019, 11:05:33 AM »
You can also move the nitrogen into the aromatic ring, you can have o-,m-, and p- Methylpyridine. Also called Picoline. So 8 Isomeres in total.

These would only have 6 carbons, but yes.

Offline chenbeier

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Re: How many isomers are in this molecule?
« Reply #11 on: October 13, 2019, 11:10:36 AM »
Oh yes Pyrrol derivates, So never ending.

Offline chenbeier

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Re: How many isomers are in this molecule?
« Reply #12 on: October 13, 2019, 11:12:21 AM »
You can also move the nitrogen into the aromatic ring, you can have o-,m-, and p- Methylpyridine. Also called Picoline. So 8 Isomeres in total.

These would only have 6 carbons, but yes.

I changed it to the ethylproduct and add the dimethyl-isomeres above.

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