Near infrared two-photon-excited and -emissive dyes based on a strapped excited-state intramolecular proton-transfer (ESIPT) scaffold

Papers published
N. Suzuki, K. Suda, D. Yokogawa, H. Kitoh-Nishioka, S. Irle, A. Ando, L. M. G. Abegão, K. Kamada, A. Fukazawa, and S. Yamaguchi, Chem. Sci., 9, 2666-2673 (2018), DOI: 10.1039/C8SC00066B
  • Fluorophores that can undergo excited-state intramolecular proton transfer (ESIPT) represent promising scaffolds for the design of compounds that show red-shifted fluorescence. Herein, we disclose new near infrared-emissive materials based on a dialkylamine-strapped 2,5-dithienylpyrrole as an ESIPT scaffold. The introduction of electron-accepting units to the terminal positions of this scaffold generates acceptor-p-donor-p-acceptor (A-p-D-p-A) type p-conjugated compounds. Following the ESIPT, the electron-donating ability of the core scaffold increases, which results in a substantially red-shifted emission in the NIR region, while increasing the oscillator strength. The electron-accepting units play a vital role to achieve intense and red-shifted emission from the ESIPT state. The strapped dialkylamine chain that forms as intramolecular hydrogen bond is also essential to induce the ESIPT. Moreover, an extended A-p-D-p-A skeleton enables two-photon excitation with the NIR light. A derivative bearing borylethenyl groups exhibited an intense NIR emission in polar solvents with a strong two-photon-absorption band in the NIR region.

Bookmark this on Hatena Bookmark
Hatena Bookmark - Near infrared two-photon-excited and -emissive dyes based on a strapped excited-state intramolecular proton-transfer (ESIPT) scaffold
Share on Facebook
Post to Google Buzz
Bookmark this on Yahoo Bookmark
Bookmark this on Livedoor Clip
Share on FriendFeed
[`tweetmeme` not found]
[`grow` not found]