Excitation shift

Chattopadhyay A, Mukherjee S (1999) Red edge excitation shift of a deeply embedded membrane probe implications in water penetration in the bilayer. J Phys Chem B 103(38) 8180-8185... 

Haidar S, Chattopadhyay A (2007) Dipolar relaxation within the protein matrix of the green fluorescent protein a red-edge excitation shift study. J Phys Chem Bill 14436-9... 

Table 3-9. Computed excitation shifts (cm 1) of acetone3 relative to the gas-phase result in water, MeCN and CCI4...

Since N->Vi excitation shifts the electrons from the exocyclic atom into the nucleus, the pK values of the excited state will be more negative. In their preparative separation and isolation the solubility of thiopyrones in relatively concentrated acids is often used, as the thiopyrones reprecipitate on dilution with water. However, in our experience considerable decomposition often occurs under these conditions. The driving force in forming the salt arises from the emergence of the pyrylium system (47). 

Shifted excitation Raman difference spectroscopy (SERDS) One way to remove the fluorescent background in traditional Raman Spectroscopy is to take advantage of the shift response of the Raman Effect to excitation wavelength shifts. In SERDS, two spectra of a sample are acquired with slightly different excitation wavelengths, and are then subtracted to estimate the Raman spectrum of a sample. This difference will impact the Raman spectra where the entire spectrum will shift in energy by the amount of excitation shift [16]. 

The red-edge excitation spectra and anisotropy measurements yield information on the dynamics of the fluorophore and of its environment. At high concentration of calcofluor compared to that of a i-acid glycoprotein, a red-edge excitation shift is observed (Fig. 8.23a). This shift indicates that the microenvironment of the fluorophore exhibits restricted motions. Therefore, the carbohydrate residues in the vicinity of calcofluor are rigid and do not show any segmental motions. 

As the size of the clusters becomes smaller and approaches the Bohr radius of the bulk exciton, quantum confinement effects will become apparent. The electronic excitations shift to higher energy, and the oscillator strength will be concentrated in just a few transitions, so changing the density of electronic states and leading to blue shifts of the absorption band edge [4j, That is not sensitive for routine absorption spectra of nanoclusters for surface states and absorption of outside molecules. The fluorescence of nanoclusters is, by contrast, quite sensitive to surface conditions associated with surface localized states. For strong confinement, an analytic approximation obtained by Brus for the lowest excited state for small R is... 

Chattopadhyay A, Mukherjee S (1993) Fluorophore environments in membrane-bound probes— red edge excitation shift study. Biochemistry 32(14) 3804-3811. doi 10.1021/ bi00065a037... 

Tiivedi ER, Eliseeva SV, Jankolovits J, Olmstead MM, Petoud S, Pecoraro VL (2014) Highly emitting near-infrared lanthanide encapsulated sandwich metallacrown complexes with excitation shifted toward lower energy. J Am Chem Soc 136(4) 1526-1534... 

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