Absolute luminescence yield of cresyl violet. A standard for the red

Abstract

Publication costs assisted by the Petroleum Research Fund and the National Science Foundation We measure ( for the oxazine dye cresyl violet to be 0.54s in methanol, at 22 °C, for excitation from 540 to 640 nm. With a mean emission wavelength near 638 nm, this should be a useful luminescence quantum yield standard for the red. We judge our absolute accuracy to be well within 10% and probably better than 5%. The yield is rather insensitive to conditions even including choice of solvent. It is constant from extreme dilution up to above 10~4 M; but absorption-emission overlap makes it a convenient standard only for relative measurements which use "dilute" procedures. We employed two independent and completely different calorimetric methods to achieve an absolute measurement which is independent of all previous luminescence yield data: photomicrocalorimetry, an optimized conventional technique, and thermal blooming, a new laser approach. We report also determinations relative to presently accepted standards.

Higher fluorescence in platinum(iv) orthometallated complexes of perylene imine compared with their platinum(ii) or palladium(ii) analogues

“…Luminescence data were recorded on a Perkin--Elmer LS--luminescence spectrometer, in CHCl 3 (1 × 10 --5 M) and in solid state measurements were made using finely pulverized KBr dispersions of the sample in 5 mm quartz tubes at room temperature. Luminescence quantum yields were obtained at room temperature using the optically dilute method (A < 0.1) in degassed chloroform (quantum yields standard were perylene in methanol (Ф fl = 0.92), 24 rhodamine B in ethanol (Ф fl = 0.70), 33 and cresyl violet in ethanol (Ф fl = 0.54) 34 and using an excitation wavelength of 434, 510 and 540 nm, respectively nm). The emission lifetime measurements were carried out with a Lifespec--red picosecond fluorescence lifetime spectrometer from Edinburgh Instruments.…”

Carrier recombination dynamics in individual CdSe nanowires

“…45 Both systems were excited at 2.30 eV (540 nm) with their absorbances matched at the excitation wavelength. Differences in solvent refractive indices as well as spectrometer sensitivities were taken into account.…”

CGP 55398, a liposomal Ge(IV) phthalocyanine bearing two axially ligated cholesterol moieties: a new potential agent for photodynamic therapy of tumours

“…In the case of GePc the strong overlap between the lowest energy absorption band and the fluorescence emission may cause optical artifacts arising from inner filter and/or trivial reabsorption effects; therefore, in order to minimise such effects, the GePc solutions were always kept at an optical density lower than 0.05 at both the excitation and maximum absorption wavelengths. The quantum yield of GePc fluorescence was calculated by comparison of the area below the corrected emission spectrum for a 0.01 gM phthalocyanine solution in chloroform with that of cresyl violet chosen as a fluorescence standard (quantum yield 0.54 in methanol; Magde et al, 1979).…”