Masahiro Kotani

We report results of single Molecule study of phosphorescent organometallic complex, tris(2-phenylpyridine)-iridium (Ir(ppy)(3)). Single molecule emission intensities show a wide multi-component distribution. Photobleaching times of molecules emitting with particular intensity are exponentially distributed. The dependence of the inverse of the mean photobleaching time on the emission intensity reveals linear dependence for lower intensities and more complex behavior for higher intensities. The results obtained on Ir(ppy)(3) are compared with those of a fluorescent label, diethyloxacarbocyanine. (C) 2004 Elsevier B.V. All rights reserved.

We present a simple and straightforward method for determining absolute spatial orientations of transition dipole moments of single fluorescent molecules. Far-field polarization microscopy provides angles of the dipole moments projected in the plane of the sample. Optical field near total internal reflection surfaces has a strong component perpendicular to the sample and, for a given in-plane angle, provides unambiguous orientation of the molecular dipole moment. Experimentally, both excitation modes are alternated to monitor real-time conformational dynamics of tetramethylrhodamine molecules covalently attached to a quartz substrate. (C) 2003 American Institute of Physics.

Molecular orientation in thin films of methylene blue, prepared by dip-coating. has been studied by UV-visible absorption spectroscopy and X-ray diffraction. In multilayered films the molecules are essentially standing normal to the surface of a fused quartz substrate and form a layered structure with a periodicity that corresponds to the molecular length. Due to this arrangement the film is only faintly colored, since, with normal incidence, the electric field of the incident light is orthogonal to the transition moment of the molecules, This structure can be formed by self-organization in the course of drying. not by epitaxy. (C) 2001 Elsevier Science B.V. All rights reserved.

Molecular orientation in thin films of methylene blue, prepared by dip-coating. has been studied by UV-visible absorption spectroscopy and X-ray diffraction. In multilayered films the molecules are essentially standing normal to the surface of a fused quartz substrate and form a layered structure with a periodicity that corresponds to the molecular length. Due to this arrangement the film is only faintly colored, since, with normal incidence, the electric field of the incident light is orthogonal to the transition moment of the molecules, This structure can be formed by self-organization in the course of drying. not by epitaxy. (C) 2001 Elsevier Science B.V. All rights reserved.