Xinxiu Fang, Shoufeng Zhang, Guiyan Zhao
Feb 1, 2014
Citations
0
Influential Citations
51
Citations
Journal
Dyes and Pigments
Abstract
Abstract A rhodamine - azacrown derivative (2-(2-(1,4-dioxa-7,13-dithia-10-azacyclo- pentadecan-10-yl)ethyl)-3′,6′-bis(diethyl amino)spiro[isoindoline-1,9′-xanthen]-3-one) responded to Al 3+ and Fe 3+ in ethanol–water solutions (20/80, v/v, pH = 7.0) and selectively responded to Al 3+ in acetonitrile. In addition, it bound to the cation with a simple 1:1 mode in aqueous solutions and 2:1 mode in acetonitrile. The association constants (logKa) of the sensor for Fe 3+ and Al 3+ were obtained to be 6.5 and 3.6 in ethanol–water, and the corresponding detection limits were calculated to be 1.2 and 8.6 × 10 −8 M, respectively, while the association constant (logKa) for Al 3+ was 3.9 with a detection limit of 5.9 × 10 −7 M in acetonitrile under our experimental conditions. Nuclear magnetic resonance and other investigations indicated that in acetonitrile the existence of the second Al 3+ shifted the binding location of the first Al 3+ , which led to the spirolactam ring-open and fluorescence formation. The mechanisms for the sensor to Al 3+ and Fe 3+ in different solvents are discussed in detail.