Showing papers on "Stokes shift published in 1975"
TL;DR: In this article, a new and sensitive method for the study of vibrational relaxation in the ground electronic state of molecules has been applied to dilute solutions of Rhodamine 6G in alcohols.
Abstract: A new and sensitive method for the study of vibrational relaxation in the ground electronic state of molecules has been applied to dilute solutions of Rhodamine 6G in alcohols. The method takes advantage of the large electronic cross sections to prepare the molecules in vibrationally excited states and probe their return to the ground state. The influence of the solvent on our experimental observations is discussed. A study of the effect of dielectric relaxation and hydrogen bonding on the Stokes shift justifies the interpretation of our results in terms of vibrational relaxation.
50 citations
TL;DR: In this article, it is shown that lead sulphate, PbSO4, shows Pb2+ emission with a large Stokes shift, and energy transfer has been observed from the Pb 2+ ions to several luminescent centres, viz., tungstate, molybdate, vanadate and rare earths.
16 citations
TL;DR: In this article, the fluorescence spectrum of polycrystalline tetracene has been measured in the temperature range 4.2 to 300 K and the 0-0 transition occurs at 18700 ± 20 cm −1 independent of temperature and crystal structure.
14 citations
TL;DR: In this paper, the irigins of the halfwidths of both orange and red, as well as IR, luminescence bands in specially undoped CdS single crystals were investigated.
10 citations
TL;DR: In this paper, it was shown that the iterative procedure SCF-CI-SC can be successfully used for calculation of the Stokes shift, FC luminescent maxima and equilibrium molecular geometry in excited states of compounds which have strong bond alterna- tion in their ground state.
9 citations
TL;DR: In this paper, pressure dependences of absorption-and emission-band shapes of vibrationally assisted electronic transitions within impurities in solids were determined for a number of properties of absorption and emission-bands.
Abstract: Pressure dependences are determined for a number of properties of absorption- and emission-band shapes of vibrationally assisted electronic transitions within impurities in solids. The vibrational coupling of the impurity to the lattice includes both linear and quadratic interaction terms, as well as different pressure couplings in the ground and excited electronic states. The pressure-dependent properties that are examined include the zero-phonon-line energy, the first three moments, the centroid shift from the zero-phonon line, and the Stokes shift. In general, all these properties have pressure dependences that involve the quadratic interaction parameter and the difference in the pressure coupling to the ground and excited electronic states. These pressure-dependent effects are shown to arise through a pressure-dependent Huang-Rhys factor and a pressure-dependent energy separation between the minima of the electronic ground and excited states.
6 citations
Journal Article•
TL;DR: In this article, the second derivative of absorption, fluorescence and fluorescence excitation spectra of chlorophyll a in concentrated solutions and films was investigated, and 14 forms of pigment aggregates, which can be divided into two types--with narrow 8-10nm and wide (25-40nm) low temperature (-196 degrees C) spectra bands, were found.
Abstract: The second derivative of absorption, fluorescence and fluorescence excitation spectra of chlorophyll a in concentrated solutions and films was investigated. More than 14 forms of pigment aggregates, which can be divided into two types--with narrow 8-10nm) and wide (25-40nm) low temperature (-196 degrees C) spectra bands, were found. For the most part of the aggregated forms, the position and half width of the bands, as well as the Stokes shift and relative quantum yield were determined. The comparison of the spectral characteristics points to the indentity of the aggregates and corresponding native forms of Chl. a. It is shown that the universal relationship between absorption and fluorescence bands in applicable to the aggregates of the two types and the energy of resonance interaction between monomers in the aggregates is evaluated.
5 citations
4 citations