Exciton coupling of localised chromophore states within covalently bound superchromophores is a viable strategy to modify optical properties such as spectral broadening and red-shifting of absorption bands. These are desirable properties for e.g. organic photovoltaic applications. Attaching three squaraine dyes to a central nitrogen core in a star-shaped manner leads to the formation of superch...

The spectral characteristics of 1,2,3,8-tetrahydro-1,2,3,3,8-pentamethyl-5-(trifluoromethyl)-7H–pyrrolo[3,2-g]quinolin-7one (LD-473) were demonstrated in liquid and solid states. For the liquid state, the absorption and fluorescence spectra of the LD-473 in Methyl Methacrylate showed bands at 385 and 420 nm, respectively. LD-473 in the solid state showed one absorption band at 530 nm, while the...

Fluorescence-based approaches for determining phytoplankton biomass have been under-utilized in comparison to applications based on blue/green wavelength reflectance ratios. In part, the under utilization is due to attenuation of the fluorescence signal by high water absorption in the red, in contrast to the greater transmission, and hence, depth penetration, of blue and green wavelengths. In n...

9-Anthryl-oligothiophenes (9A-T., n= l-4) have been studied in n-hexane solution between helium and room temperature using absorption, fluorescence emission and excitation spectra and time resolved fluorescence measurements. These compounds are reference systems for studies on intramolecular energy and charge transfer in donor/acceptor-substituted conjugated chain molecules. The absorption spec...

Spectral changes of bovine serum albumin (BSA) in the presence of dipicolinic acid (DPA) were studied with UV/Vis absorption and fluorescence spectroscopy. The change in UV/vis spectra of BSA in the presence of DPA indicated the protein weakly interacting with DPA. The DPA quenching to the fluorescence of BSA leads to the calculation of the BAS-DPA association constant K of 8.9 x 104 Lmol-1 at ...

The effects of precursor solvent on the optical properties and morphology of poly(p-phenylene vinylene) (PPV) films are investigated using X-ray diffraction, steady state absorption and fluorescence, and picosecond time-resolved spectroscopy. Precursor films spin cast from water yield PPV films with higher average crystallite size and conjugation than films cast from methanol. These changes aff...

The nature of one and two-photon absorption enhancement in a series of oligothiophene dendrimers, recently proposed for applications in entangled photon sensors and solar cells, has been analyzed using both theory (time dependent density functional theory calculations) and experiment (fluorescence upconversion measurements). The linear absorption spectra exhibit a red shift of the absorption ma...

Uphill energy transfer in the LH2-containing purple bacteria Rhodopseudomonas acidophila, Rhodopseudomonas palustris, Rhodobacter sphaeroides, Chromatium vinosum and Chromatium purpuratum was studied by stationary fluorescence spectroscopy at room temperature upon selective excitation of the B800 pigments of LH2 and the B880 pigments of LH1 at 803 nm and 900 nm, respectively. The resulting fluo...