6. Rehybridization of the Acceptor (RICT) 3908 7. Planarization of the Molecule (PICT) 3909 III. Fluorescence Spectroscopy 3909 A. Solvent Effects and the Model Compounds 3909 1. Solvent Effects on the Spectra 3909 2. Steric Effects and Model Compounds 3911 3. Bandwidths 3913 4. Isoemissive Points 3914 B. Dipole Moments 3915 C. Radiative Rates and Transition Moments 3916 1. Quantum Yields and Radiationless Deactivation Processes 3916

Structural Changes Accompanying Intramolecular Electron Transfer: Focus on Twisted Intramolecular Charge-Transfer States and Structures

Radiative decay engineering: biophysical and biomedical applications.

Small-molecule fluorescent probes embody an essential facet of chemical biology. Although numerous compounds are known, the ensemble of fluorescent probes is based on a modest collection of modular “core” dyes. The elaboration of these dyes with diverse chemical moieties is enabling the precise interrogation of biochemical and biological systems. The importance of fluorescence-based technologies in chemical biology elicits a necessity to understand the major classes of small-molecule fluorophores. Here, we examine the chemical and photophysical properties of oft-used fluorophores and highlight classic and contemporary examples in which utility has been built upon these scaffolds.

/pdf/bright-ideas-for-chemical-biology-sg3vg8z8cw.pdf

Bright Ideas for Chemical Biology

Fluorescent labeling of biomolecules with organic probes.

Fluorescent Dyes and Their Supramolecular Host/Guest Complexes with Macrocycles in Aqueous Solution Roy N. Dsouza, Uwe Pischel,* and Werner M. Nau* School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany Centro de Investigaci on en Química Sostenible (CIQSO) and Departamento de Ingeniería Química, Química Física y Química Org anica, Universidad de Huelva, Campus de El Carmen s/n, E-21071 Huelva, Spain

Fluorescent dyes and their supramolecular host/guest complexes with macrocycles in aqueous solution.

Environmentally sensitive fluorescent probes involve two groups, an electron donor and an electron acceptor, attached to an aromatic ring system, and maximal effects may be expected when these groups are as far apart as feasible. The syntheisis, characterization, and spectroscopic properties of 6-propionyl-2-(dimethylamino)naphthalene (PRODAN), a compound that fulfills these conditions, are described. The maximum of emission is at 401 nm in cyclohexane solution and at 531 nm in water solution, indicating an increase of dipole moment of approximately 20 D units on excitation to the lowest singlet state. The effect of temperature upon the spectral distribution and the bandwidth of fluorescence of PRODAN in 1:1 complexes with albumin shows the existence of a dynamic relaxation process of the protein surroundings within th 2-4 ns of the fluorescence lifetime.

Fay J. Farris

Papers

Synthesis and spectral properties of a hydrophobic fluorescent probe: 6-propionyl-2-(dimethylamino)naphthalene.

Preparation, crystalline structure, and spectral properties of the fluorescent probe 4,4'-bis-1-phenylamino-8-naphthalenesulfonate