ChemInform Abstract: OBSERVATION OF AN UNPRECEDENTED HEAVY‐ATOM EFFECT ON THE RATE OF 1N,Π IN A β,Γ‐UNSATURATED KETONE

Abstract

Das Butanon (II), dessen direkte Photolyse das Methylketon (I) liefert, und das bei Aceton‐sensibilisierter Anregung außerdem das bicyclische Keton (III) als Produkt einer 1,2‐sigmatropen Acetylverschiebung bildet, zeigt bei einer Photoreaktion unter 2.2 at Xe eine Abnahme der Intensität der Fluoreszenz von (II) um 21% bei gleichzei‐ tiger Steigerung der Quantenausb.

Room-Temperature Phosphorescence from Encapsulated Pyrene Induced by Xenon

“…39 Xe's impact on S 1 to T 1 intersystem crossing in aromatics and enones has been documented. [40][41][42]44,46 This phosphorescence is observed only from pyrene@OA 2 suggested that the perturber Xe and the emitter pyrene must be close to each other. Xe being ineffective in solution but effective in bringing about phosphorescence in solid zeolites indicated the need for the emitter and Xe to be close proximity for a longer time.…”

“…Unlike Tl + , the heavy atom valued for bringing about phosphorescence at room temperature from supramolecular encapsulated guests including in the recent example with an organic cavitand and pyrene as the host and guest, respectively, and heavy atom xenon, soluble in isotropic solvents, has attracted little attention . Although xenon’s effect on intersystem crossing (S 1 to T 1 and T 1 to S 0 ) is well documented, − very few publications mention about xenon-induced phosphorescence in solution at room temperature. The continued interest on room-temperature phosphorescence employing supramolecular assemblies motivated us to examine the process using octa acid (OA, Figure b) , as the host and xenon and Tl + as the heavy atom perturbers.…”