X-ray crystallographic and photophysical properties of rhodamine-based chemosensor for Fe3+

A fluorescent sensor for Fe3+, 2-[3'.6'-bis(ethylamino)-2',7'-dimethyl-3-oxospiro[1H-isoindole-1,9'-[9H] xanthen]-2-((2-aminoethyl)methyl)]phenol, has been synthesized and characterized by H-1 NMR, C-13 NMR and X-ray crystallography. The photophysical processes of the Fe3+-sensor have been carefully investigated by fluorescence and absorbance spectra. Upon addition of Fe3+, the sensor shows strong fluorescence change with absorbance and emission peaks at 530 and 554 nm, respectively. Other metal ions have no such response. (C) 2009 Elsevier B.V. All rights reserved.