Fluorescence investigation of model compounds for light-emitting alternating copolymers in heterogeneous environments.
In this paper, the fluorescence spectra of the model compounds M(TPA-PPV) and M(TPA-PAV) of novel light-emitting alternating copolymers, were studied and the effect of KNO3 on the interaction between the model compounds and the ionic micelle-water interface was also investigated. The following is found: (i) the fluorescence changes of M(TPA-PPV) are related to the state of cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) solution: (ii) an aggregated state can be formed in M(TPA-PAV) solution at low concentration of CTAB; (iii) higher concentrations of KNO3 may affect the interaction between the model compounds and the ionic micelle-water interface.
Thermodynamic study on the effects of beta-cyclodextrin inclusion with anilinonaphthalenesulfonates.
Thermodynamic parameters and stoichiometries for the binding of anilinonaphthalenesulfonates to beta-cyclodextrin are obtained from steady-state fluorescence intensity and anisotropy measurements. Specifically, formation constant, enthalpy, and entropy values are obtained for complexes of beta-cyclodextrin with eight different substrate molecules at five different temperatures and six different pH values, and their associated errors are given. We propose an explanation of the relative magnitudes of the values obtained with regard to the geometry of the substrate and the importance of the various noncovalent interactions responsible for the complexation.
The Amidinium–Carboxylate Salt Bridge as a Proton-Coupled Interface to Electron Transfer Pathways†
The ruthenium and osmium complexes were prepared according to literature procedures [ l l ] . NBE was purchased from Fluka, and DCPD (technical quality, 94%) from Shell and used as received. Viscosimetric measurements were performed on a home-built, real-time viscosimeter. Gel times were recorded on a Brookfield viscosimeter, DSCs on a Mettler DSC30 with a Mettler TCll controller, TGAs on a Mettler TG50 with a Mettler TCfOA controller, and surface roughness on a Form Talysurf S3C-50. Micro hardness was determined on a Fischerscope H100. I3C CP-MAS NMR spectra of a piece of poly(DCPD) that was tightly fitted into the spinner were recorded on a Bruker 400-MHz instrument with a MAS rate of 11 kHz and a pulse delay of 5 s (a pulse delay of 60 s gave an identical result).