title: Synthesis and photophysical properties of N-fused tetraphenylporphyrin derivatives: near-infrared organic dye of [18]annulenic compounds.
abstract: A variety of N-fused porphyrin derivatives were prepared and their photophysical properties were investigated. Although intact N-fused tetraarylporphyrins showed almost no emission, introduction of electron-withdrawing groups such as a nitro group and a cyano group on the macrocycles caused significant refinements in their emission efficiency. Long emission wavelengths (900-1000 nm) as well as fairly large Stokes shifts (∼1200 cm(-1)) are exceptionally unique photophysical properties among [18]annulenic compounds, which could be rationalized by the excited state intramolecular proton transfer (ESIPT) process. Relatively weak emission quantum yields (∼5.0 × 10(-4)) and unusually short S(1) state lifetimes (∼13.5 ps) are in good agreement with the ESIPT process. The solvent and substituent effects on the photophysical properties are also discussed in conjunction with the theoretical studies, where the mesityl groups at the meso-positions play a unique role.
authors.affiliation: Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Ikeda
authors.forename: Motoki
authors.initials: M
authors.lastname: Toganoh
authors.forename: Shanmugam
authors.initials: S
authors.lastname: Easwaramoorthi
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Lim
authors.forename: Dongho
authors.initials: D
authors.lastname: Kim
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Furuta
mesh_terms: D004396:Coloring Agents / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010777:Photochemistry; D011166:Porphyrins / Q000138:chemical synthesis* / Q000737:chemistry; D011789:Quantum Theory; D012997:Solvents / Q000737:chemistry
chemical_list: D004396:Coloring Agents; D011166:Porphyrins; D012997:Solvents; C409084:tetraphenylporphyrin