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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: myii on May 15, 2021, 11:53:31 AM

Title: Photolysis mechanism of acetone
Post by: myii on May 15, 2021, 11:53:31 AM: Hi

Can someone show me what the mechanism would be for the photolysis of acetone? Should methyl radicals form?
Title: Re: Photolysis mechanism of acetone
Post by: rolnor on May 15, 2021, 12:15:42 PM: https://pubs.acs.org/doi/10.1021/j100841a010#
Title: Re: Photolysis mechanism of acetone
Post by: myii on May 15, 2021, 02:18:21 PM: Quote from: rolnor on May 15, 2021, 12:15:42 PM
https://pubs.acs.org/doi/10.1021/j100841a010#

Thanks for this :) so would the mechanism be just a free radical mechanism? As I am little confused about something, if the question asked 'show the photolysis mechanism of acetone' would you need to draw a mechanism so showing half arrows etc or do you think the mechanism shown on the paper you have given me is sufficient?
Title: Re: Photolysis mechanism of acetone
Post by: Babcock_Hall on May 15, 2021, 03:55:06 PM: Drawing a mechanism on an exam generally entails including mechanistic arrows.
Title: Re: Photolysis mechanism of acetone
Post by: myii on May 16, 2021, 02:37:21 AM: Quote from: Babcock_Hall on May 15, 2021, 03:55:06 PM
Drawing a mechanism on an exam generally entails including mechanistic arrows.

Ahhh ok, how would the arrows be drawn for the photolysis of acetone if this is the case?
Title: Re: Photolysis mechanism of acetone
Post by: Babcock_Hall on May 16, 2021, 11:09:24 AM: Yes, and if the mechanism involves single electrons, one uses single-barbed arrows.
Title: Re: Photolysis mechanism of acetone
Post by: myii on May 19, 2021, 03:26:56 AM: Quote from: Babcock_Hall on May 16, 2021, 11:09:24 AM
Yes, and if the mechanism involves single electrons, one uses single-barbed arrows.

Ah okay:), how would the mechanism look like I am really struggling still :( I know a radical is form from the acetone
Title: Re: Photolysis mechanism of acetone
Post by: myii on May 19, 2021, 07:39:22 AM: Quote from: Babcock_Hall on May 16, 2021, 11:09:24 AM
Yes, and if the mechanism involves single electrons, one uses single-barbed arrows.

Would this be the mechanism?
Title: Re: Photolysis mechanism of acetone
Post by: Babcock_Hall on May 19, 2021, 09:27:59 AM: Your drawing makes it looks as if everything happens in a single step. The mechanism takes several steps, as shown at the link above. I would use their mechanism as a starting point and add arrows.