A new boradiazaindacene (BODIPY) derivative (1a) bearing simple NO bidentate ligands has been synthesized. The 1a molecule behaves as a fluorescent probe for Cr(3+) and shows shows a strong red fluorescence upon coordination with Cr(3+), while showing almost no fluorescence for other metal cations. (C) 2010 Elsevier Ltd. All rights reserved.