Search

Abstract: Telluroxanthone shows a r.t. phosphorescence at λ max =510nm. The emitting state is of the CT type involving Te as donor and the carbonyl substituent as acceptor. An analogy between the emitting CT triplet of telluroxanthone and emitting MLCT triplets of transition metals complexes is emphasized. [Copyright &y& Elsevier]

Abstract: Dry silver sulfadiazine (AgSD) is not light sensitive but shows a greenish-blue r.t. photoluminescence at λ max =482nm which is suggested to originate from an IL triplet. In the presence of water AgSD undergoes a partial hydrolysis with the formation of free sulfadiazine (HSD) which has been previously shown to be photoreactive. Moreover, irradiation of an aqueous suspension of AgSD leads also to the photoreduction of Ag+ to elemental silver. This photolysis might explain the origin of argyria which can occur when AgSD in contact with human skin is exposed to sun light [Copyright &y& Elsevier]

Abstract: The oxonium ions and are phosphorescent at r.t. and 77K, respectively. It is suggested that these ions which are characterized by a rather flat trigonal pyramid in the ground state undergo a distortion to a steeper pyramid in their phosphorescent states. This structural change is caused by metal–metal bonding in the excited state. [Copyright &y& Elsevier]

Abstract: The solid compound Ag(binap)NO3 with binap=2,2′-bis(diphenylphosphino)-1,1′-binaphthyl shows an IL phosphorescence at λ max =510nm under ambient conditions. The silver–phosphine bonding is sufficiently covalent to transmit the heavy-atom effect of silver to the binaphthyl chromophore. [Copyright &y& Elsevier]

Abstract: The complex PtII(cyclooctatetraene)(CN)2 shows a longest-wavelength absorption (λ max =430nm) which is assigned to a (PtII →π∗ C8H8) MLCT transition. At r.t. the solid complex displays an intense orange emission at 572nm which originates from the MLCT triplet. The emission spectrum exhibits a vibrational structure which may indicate an IL contribution. [Copyright &y& Elsevier]

With regard to its electronic structure, the cation Icoll2+ (coll = collidine or 2,4,6-trimethylpyridine) is viewed as a coordination compound of iodine(I) with a p4 electron configuration. The lowest-energy excited state of Icoll2+ is suggested to be a ππ* collidine intraligand (IL) triplet which appears in absorption (λmax=332 nm, ϵ=250) and emission (λmax=405 nm, φ=0.001, τ∼90 ns). Owing to the heavy-atom effect of iodine this phosphorescence occurs at r.t. The longest-wavelength pp absorption is apparently obscured by the intense spin-allowed IL band at λmax=268 nm. [Copyright &y& Elsevier]