Synthesis and chemosensitivity of a new iminium salt toward a cyanide anion

Abstract

A short, high-yielding route to pyranylidene Iminium (Imi) salts using a new pyrylium salt reaction between N,N-Dimethylformamide (DMF) and acetic anhydride is reported. The Imi salt-sensing behavior toward various anions has been investigated using UV-Visible spectroscopy. The Imi salt demonstrates high selectively for CN- when various other anions, such as CN-, Cl-, Br-, I-, SCN-, CIO4-, NO3-, HSO4-, PF6- and N-3(-) are present because it is highly reactive towards nucleophiles. The selective detection of CN- with the Imi unit gave rise to a significant hypochromic shift in the CH3CN solution at lambda(max) = 444 nm and 423 nm and creation of new peak at 252 nm. These studies indicated that CN- had high affinity toward Imi, forming a 1:1 complex; this observation agrees with the current understanding of these materials. (C) 2014 Elsevier B.V. All rights reserved.