Timeline for Compounds with fluorescence and/or phosphorescence, what can do both?
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Sep 20, 2023 at 12:10 | comment | added | Neal Conroy | @porphyrin oh, so pentacene is a good example for something that does both? It's high molecular weight and rigid, so that's in line for good phosphorescence? | |
| Sep 20, 2023 at 6:51 | comment | added | porphyrin | @Neal Conroy Pentacene is highly fluorescent, did you mean fluorescence but not phosphorescence. I can se no reason why it does not fluoresce, as do naphthalene and anthracene. | |
| Sep 19, 2023 at 23:17 | comment | added | Neal Conroy | @porphyrin another compound that does phosphorescence but not fluorescence, is pentacene? For same reasons or different reasons as benzophenone? | |
| Jul 25, 2023 at 14:17 | comment | added | porphyrin | I was describing what happens in discrete molecules only, in materials such as semiconductors electron - hole recombination can lead to luminescence. | |
| Jul 25, 2023 at 13:31 | comment | added | Neal Conroy | @porphyrin Ed V I had only recently found out that the mechanism behind glow-in-the-dark toys, is not phosphorescence, but called persistent luminescence. Which is something in its Wikipedia article said the mechanism is not fully understood, and it is commonly mistaken as phosphorescence. According to an 2009 article written by a chem professor "the challenge of finding an efficient red emitting persistent phosphor is still waiting." So those 3, and chemiluminescence, are like 4 categories of its own. What do you guys call the study of this? I guess either photochemistry or photophysics. | |
| Jul 25, 2023 at 6:41 | comment | added | porphyrin | @ed V thanks, I had forgotten about ionisation. | |
| Jul 25, 2023 at 6:40 | comment | added | porphyrin | It is true that Benzophenone has almost 100% intersystem crossing forming triplets and these are used to sensitise reactions. Phosphorescence is observed in O2 free solutions (Parker & Joyce, Chem. Comm, 1968, p749) | |
| Jul 24, 2023 at 18:00 | comment | added | Ed V | @NealConroy The Hope diamond is blue and famously phosphoresces a deep red color. Phosphoresce is rare compared to fluorescence and especially so in liquid solutions at room temperature and in the presence of oxygen. | |
| Jul 24, 2023 at 17:39 | comment | added | Neal Conroy | Anyways, a compound I hear that does phosphorescence but not fluorescence (or poorly fluorescence), is benzophenone, I believe, at room temperature. | |
| Jul 24, 2023 at 16:48 | comment | added | Ed V | (+1) Nice answer! Back in the early 1980s, I used to do laser-excited two photon photoionization of PAHs in solvents such as n-hexane. I used a pulsed nitrogen laser at about 337 nm. So sometimes excited molecules can suffer another fate: get hit again and ionize. ;-) | |
| Jul 24, 2023 at 16:33 | history | answered | porphyrin | CC BY-SA 4.0 |