title: 2,3-Naphtho-Fused BODIPYs as Near-Infrared Absorbing Dyes.
abstract: 2,3-Naphtho-fused boron-dipyrromethenes (BODIPYs) 1a and 1b, which absorb near-infrared light at 740-770 nm with molar extinction coefficients above 10(5) M(-1) cm(-1) in THF, have been synthesized through a palladium(II)-catalyzed direct acylation of N-BOC hydrazones and subsequent Paal-Knorr pyrrole synthesis. Simple benzo-annulation of dibenzo-BODIPY caused a significant red-shift in the absorption. Subsequent intramolecular B,O-cyclization of 1b gave 2, which exhibited an intense absorption band at 830 nm. The structure-optical property relationship has been investigated using theoretical calculations and cyclic voltammetry.
authors.affiliation: Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University , 1-1 Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Yamazawa
authors.affiliation: Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University , 1-1 Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Nakashima
authors.affiliation: Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University , 1-1 Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan.
authors.forename: Yukie
authors.initials: Y
authors.lastname: Suda
authors.affiliation: Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University , 1-1 Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan.
authors.forename: Ryuhei
authors.initials: R
authors.lastname: Nishiyabu
authors.affiliation: Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University , 1-1 Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kubo