Hideki Gorohmaru

Singlet oxygen generation by two-photon excitation of porphyrin derivatives having two-photon-absorbing benzothiadiazole chromophores

Porphyrin derivatives with four two-photon absorbing 2,1,3-benzothiadiazole chromophores at the meso positions provide large two-photon absorption cross-sections up to 735 GM as well as large quantum yields of one-photon singlet oxygen sensitization of ca. 0.7, leading to generation of singlet oxygen by two-photon excitation of 800 nm. The two-photon singlet oxygen sensitization is discussed on the basis of a parameter of the normalized oxygen luminescence intensity obtained from the two-photon experiment.

Benzo-2,1,3-thiadiazole-based, highly dichroic fluorescent dyes for fluorescent host?guest liquid crystal displaysElectronic supplementary information (ESI) available: general experimental details and synthesis methods for compounds 4, 6, 7, 8, 10, 11 and 12. See http://www.rsc.org/suppdata/jm/b4/b402645d/

The highly dichroic fluorescent dyes 4,7-bis(p-alkoxyphenyl)-, 4,7-bis(p-alkoxymethylphenyl)-, and 4,7-bis(p-alkoxycarbonylphenyl)-2,1,3-benzothiadiazoles have been synthesized and their dichroic properties evaluated. A solution of the former dye dispersed in the commercial liquid crystalline MLC-2039 host phase showed a dichroic ratio value for fluorescence up to 9.1.

Development of Photochromic Two-Photon Absorption Dyes

ABSTRACT We synthesized three photochromic two-photon absorptive diarylethene derivatives with styrylbenzene unit and measured two-photon absorption cross-sections at 800 nm by using an open aperture Z-scan method with 120 femtosecond pulses. It was found that two of the dyes have large values (δ = 52 GM) equivalent to AF-50.