Photochemical Upconversion: Anthracene Dimerization Sensitized to Visible Light by a Ru^II Chromophore

Abstract

Double up: Photochemical upconversion by MLCT‐sensitized triplet–triplet annihilation is demonstrated (MLCT=metal‐to‐ligand charge transfer). Selective visible excitation of [Ru(dmb)3]2+ (dmb=4,4′‐dimethyl‐2,2′‐bipyridine) in the presence of anthracene efficiently produces the [4+4] cycloaddition product. This transformation traditionally requires ultraviolet light.

Photochemical upconversion: present status and prospects for its application to solar energy conversion

“…23 TTA-UC was further employed to sensitize photochemical reactions for other applications: Islangulov et al sensitized TTA between anthracene with the metal-to-ligand chargetransfer (MLCT) sensitizer [Ru(dmb) 3 ] in order to produce reactive excited singlet species prone to cycloaddition chemistry, resulting in the formation of anthracene dimers. 130 Jiang et al used a red-absorbing porphyrin/anthracene-derivative TTA couple to sensitize trans-cis-photoisomerization of azotolane in a cross-linked liquid-crystal polymer, resulting in a photomechanical effect with potential application in soft actuation. 131 …”

An Internal Fluorescent Probe Based on Anthracene to Evaluate Cation–Anion Interactions in Imidazolium Salts

“…[49] The dimerization reaction has even been used as a fluorescent probe. [50] In principle, anthracene-based monomers can dimerize to form cis head-to-head, (9,9' and 10,10') or trans head-to-tail (9,10' and 9',10) photodimers. [51] Imidazolium salts have been reported to form trans dimers only.…”

Supramolecular activation of a molecular photocatalyst

“…The loss of the palladium dichloride moiety readily occurs under ESI-MS conditions. 22 In the case of anthracene as an interacting agent no association constant could be determined, since a fast photocatalytically induced dimerization of anthracene was competing with the intended supramolecular interaction and thus, the concentration dependent 1 44 This has been explained by a triplet-triplet energy transfer from the ruthenium chromophore to anthracene and a subsequent dimerization. Similar to these literature results, our 1 H-NMR spectroscopic investigations on a sample containing RutpphzPd and anthracene in acetonitrile showed, already with ambient light irradiation, a formation of the anthracene dimer (Fig.…”