Luminescence Lifetime-Based Sensor for Cyanide and Related Anions

Abstract

A new Ru(II) complex is described which serves as a luminescence lifetime-based sensor for fluoride and cyanide anions (KF = 640 000 mol-1, KCN = 430 000 mol-1). This chromophore displays observable changes in its UV-vis and steady-state luminescence spectra upon cyanide binding. Prior to cyanide addition, this complex exhibits a single-exponential lifetime (tau = 377 +/- 20 ns). With increasing cyanide concentrations, the intensity decays are composed of two exponentials: long tau (320-370 ns) and short tau (13-17 ns). The average lifetimes shorten as a function of cyanide concentration since the fractional intensity shifts from an initial dominant long lifetime component to the short lifetime component. This work represents the first example of a direct method for the luminescence lifetime-based sensing of anions.

Recent Advances in the Colorimetric Detection of Cyanide

“…[1] Therefore it is necessary to safely monitor and remove this dangerous anion either in industrial wastewater, after accidental release or during food production. Since the first report on the argentometric determination of cyanide by von Liebig in 1851, [8] many different detection methods including electrometric, [9][10][11] fluorometric [12,13] and chromatographic techniques [14] have been established. Drawbacks are either the laborious multistep sample pretreatment, the use of special reaction conditions as well as the low tolerance towards the presence of other anions.…”

“…This short-review focuses on the recent advances in the colorimetric detection of cyanide. Approaches like the application of CdS quantum dots [44,45] or luminescence lifetime measurements [13,26,46] will not be discussed here. The interested reader is referred to a comprehensive overview including other detection methods and historical developments by Singh et al published in 1986.…”

Di-palladium Complexes with Urea-containing Ligands as Anion Receptors

“…[22][23][24][25][26] Several groups have employed luminiscent ruthenium complexes with substituted bipyridines as chemical sensors for anions. [27][28][29][30][31][32][33][34][35] More recently, Gale and Loeb have reported a series of platinum complexes with substituted pyridine ligands as metalla-receptors for anions 20,36,37 while Anslyn has demonstrated that copper complexes of tridentate ligands (with a C 3v symmetry) can selectively bind phosphates with high associations constants. 38 As part of our ongoing interest in developing metalla-receptors for anions, [39][40][41][42][43][44][45] we have recently reported in a preliminary communication the synthesis and crystal structure of di-palladium complex 1 (see Figure 1).…”

Phosphorescent Dimesitylboryl-Appended Iridium(III) Complex for Fluoride Anion Sensing

“…However, the output signals of fluoride anion selective chemosensors have usually been absorption and/or fluorescence. 3c,9,10 Nowadays, phosphorescent chemosensors have also been developed for the detection of fluoride anions [11][12][13] since the first phosphorescent fluoride sensor reported by Gabbai et al…”