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The photophysics of a series of bis-metal doubly N-confused hexaphyrins (1.1.1.1.1.1) was investigated using various fluorescent techniques and geometry-optimized ab inito calculations. Bis-Zn(II) and free-base doubly N-confused hexaphyrins show [pi]-[pi*] transitions around a hexaphyrin ring at the B3LYP/6-3IG level and the absorption spectra of bis-Cu(II) and bis-Co(II) doubly N-confused hexaphyrins are relatively broad due to large couplings between the metal d-orbitals and [pi]-electrons of the hexaphyrin rings.

The overall excitation energy relaxation dynamics in linear porphyrin arrays and the energy transport phenomena by attaching an energy acceptor to one end of a linear porphyrin array by using steady state and time-resolved spectroscopic measurements are investigated. It is revealed that the solvation dynamics and conformational dynamics contribute significantly to the energy relaxation processes of linear porphyrin arrays.

The various photophysical properties of the three-dimensional zinc(II) prophyrin box and its constituent unit are investigated. The relationship between molecular structures in three-dimensional molecular networks and exciton coupling/transport processes is shown.

Femtosecond time-resolved emission as well as transient absorption spectroscopy of pi-conjugated polymeric thin film reveals an apparent induction time for the appearance of spectrally narrowed emission (SNE) in contrast with an instantaneous buildup of normal emission. The study on ultrafast intensity-dependent spectroscopies demonstrate that the origin of SNE phenomena in pi-conjugated polymer is amplified spontaneous emission (ASE), which induces prompt and efficient depopulation of singlet excitons.

The light emission decay in bare gold particles by using the fluorescence up-conversion technique is reported. The results indicate that a weak light emission from relatively large gold nanoparticles is attributable to the interactions between surface plasmons and incident photons that occur simultaneously with the thermal electron relaxation.

The excited-state dynamics and the photophysical properties of the representative core-modified expanded porphyrins are discussed. The discussed complexes are shown to exhibit excellent aromaticity and enhanced ring planarity, as compared to their corresponding all-aza expanded porphyrins.

[Cd.sub.1-x][Mn.sub.x]S (x=0.1-0.3) nanowires were synthesized by using the chemical vapor deposition method. The nanowires consist of single-crystalline wurtzite structured CdS with a [010] or [011] growth direction, while the XRD pattern shows the concentration of the lattice constants, confirming the incorporation of Mn into the CdS lattices.