I'm looking for a tame biochemist who I can bother with silly molecular physics questions about chlorophyll and excited states and charge separation and things.
Can anyone help me out?
Synthetic photosensitisers have excitation mechanisms involving the metal centre. In Ruthenium tris-bipyridine, for instance, an electron on the Ru2+ atom is excited, and the charge is transferred to a ligand (MLCT) by intersystem crossing. Which means charge separation, etc, etc.
But Mg2+ has the same electron configuration as Ne, and effectively has no valence electrons. So what's the excitation mechanism when the metal centre is Mg? LMCT?
Re: chlorophyll Show more
While Mg2+ has no valence electrons, Mg bound to the chlorin ligand scaffold is sharing plenty of electrons (getting a minimum of 6 or 8 electrons worth from the ligand depending on how you count 'em). The Mg center could be seen as effectively neutral.
The ligand itself is definitely able to do charge transfer, and from the (annoyingly sparse) literature available on a cursory search, I agree that something effectively MLCT is happening.
Hoping others join in here..
Re: chlorophyll Show more
@GIMcGrew Thanks. I'm a little new to coordination chemistry, so I'm still figuring things out. It's logical that the 2+ charge would be shared across the whole delocalised structure...
Annoyingly sparse is right - I spent all afternoon trying to find something on this. Though TBH I can't really blame botanists from shying away from the detailed physics!
Scholar Social is a microblogging platform for researchers, grad students, librarians, archivists, undergrads, academically inclined high schoolers, educators of all levels, journal editors, research assistants, professors, administrators—anyone involved in academia who is willing to engage with others respectfully.
We strive to be a safe space for queer people and other minorities, recognizing that there can only be academic freedom where the existence and validity of interlocutors' identities is taken as axiomatic.
"A Mastodon profile you can be proud to put on the last slide of a presentation at a conference"
(Participation is, of course, optional)
Scholar Social features a monthly "official" journal club, in which we try to read and comment on a paper of interest.
Any user of Scholar Social can suggest an article by sending the DOI by direct message to @email@example.com and one will be chosen by random lottery on the last day of the month. We ask that you only submit articles that are from *outside* your own field of study to try to ensure that the papers we read are accessible and interesting to non-experts.