Metal-free organic phosphorescent materials are attractive alternatives to the predominantly used organometallic phosphors but are generally dimmer and are relatively rare, as, without heavy-metal atoms, spin-orbit coupling is less efficient and phosphorescence usually cannot compete with radiationless relaxation processes. Here we present a general design rule and a method to effectively reduc...

The applicability of heavy atom induced room temperature phosphorescence in real samples is demonstrated in this work. In this methodology only two reagents, potassium iodide as heavy atom salt and sodium sulphite as oxygen scavenger, were used to obtain phosphorescent signal of propranolol in solution. Thus a new simple, rapid and selective phosphorimetric method is proposed for propranolol de...

Phosphorescence in ethanol and n-pentane at 77 K of the benzologues 1-8 of furan, thiophene, selenophene and tellurophene has been investigated. The rate constants of both the radiative (A.PT) and non-radiative (A:GT) deactivation of the lowest triplet state correlate linearly with X cl C2 where ck denotes the Hückel AO coefficients in the HOMO of the carbon atoms bound to the hetero-atom and (...

Emission and excitation spectra of chromone and 6-fluorochromone have been measured in the vapor phase at different temperatures and pressures along with the absorption spectra. The emission is shown to consist of the (n, *) phosphorescence accompanied by weak S1(n, *) delayed fluorescence. It is inferred from the temperature dependence of the phosphorescence intensity that the (n, *) state ...

Room-temperature phosphorescence has been observed and studied on metal-activator-free mesoporous silica. The mesoporous silica was prepared using a nonionic triblock copolymer as the mesostructure-directing agent. The as-calcined products have a well-ordered porous structure and exhibit strong phosphorescence under ultraviolet light excitation. The luminescence spectra are featured with severa...

We have demonstrated an efficient phosphorescence energy transfer (PET) system for ultrasensitive detection of DNA.

L-cysteine–capped Mn-doped ZnS quantum dots (QDs) were used for the determination of glutamic acid in foodstuffs. This method is based on measurement of the quenching of the phosphorescence intensity of the QDs after interacting with glutamic acid. A linear response was observed from 50 to 500 ng mL−1 glutamic acid with a limit of detection of 6.79 ng mL−1 . Room temperature phosphorescence (RT...

The effect of pH on the relative distribution of pyridoxal structures in aqueous solution was examined by fluorescence spectroscopy. The hemiacetal structure, which is the predominant species at neutral pH, exhibits a symmetrical emission band at 378 rnp and is characterized by a quantum yield of 0.08. Luminescence studies at low temperature (77” K) have permitted the analysis of the phosphores...

A simple optical method for the quantitative determination of dissolved oxygen under physiological conditions is described. The technique involves measurement of room temperature phosphorescence from palladiumfll) porphyrins. Such emission is rare for large organic molecules, and its long lifetime, together with the favourable absorption characteristics of the porphyrin receptor, ensure that th...