This is going to probably be an easy question for an organic chemist, but I am looking for the proper terminology to describe the following reaction mechanism.

In particular, what is a more precise way than "hydrogen stripping" to describe the process where a photogenerated hole on an oxygen can pick off the hydrogen and its associated electron to create a radical that reforms to make formaldehyde?

Further, would I say something like "an HCO radical attacks an adsorbed methoxy to create methyl formate" or is there a more precise way to talk about it? The proper reaction names would be ideal. Many thanks from a physical chemist who took orgo way too long ago!

EDIT: Thanks Orthocresol for the hint about hydrogen abstraction. Upon looking into things more, hydrogen abstraction aka hydrogen atom transfer (HAT), can be viewed as a subset of proton coupled electron transfer reactions (PCET). The difference is that HAT occurs with minimal solvent reorganization and between similar donors whereas PCET is more general where there can be heat transfer (i.e. it is diabatic versus adiabatic.) So I believe that PCET may be the proper name compared to "hydrogen/proton stripping".

One last question: does anyone know what the reaction between the HCO radical and the methoxy would be called? Thanks again!

proton stripping

  • 3
    $\begingroup$ "Abstraction", perhaps. $\endgroup$
    – orthocresol
    Nov 3, 2015 at 9:05
  • $\begingroup$ Photolysis, maybe? $\endgroup$ Nov 3, 2015 at 9:30
  • $\begingroup$ You're welcome for the "hint", but sadly that's all I can suggest, I have absolutely no experience with photochemistry. I hope you find what you are looking for. $\endgroup$
    – orthocresol
    Nov 3, 2015 at 16:28

1 Answer 1


Photocatalysis - reactions caused by light. The term seems to be predominately related to free radicals.

This is obviously a misnomer. The photon is consumed which isn't true for a "real catalyst."

I know that lasers have been used to create excited molecular states which then react. I investigated this for reactions in gas phase of different atomic isotopes of a chemical.

I think if you get any more specific than that then it degenerates into "commonly accepted names" for certain reactions. Sort of like you just have to know what acetic acid is. There is no way to "figure out" what the name means if you don't just know.

  • $\begingroup$ Right, I know that this is a photocatalytic process but that term is so generic that I want to find the proper terms. I could say something like "photo-oxidative homolytic cleavage" or something but that isn't as precise as "McMurry Coupling" which would say describe the coupling of 2 carbonyl molecules through loss of oxygen into a C=C bond, and so I was looking for the equivalent specific names here. $\endgroup$
    – Coherent
    Nov 3, 2015 at 11:36

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