Imidazo[4,5-f][1,10]phenanthroline based luminescent probes for anion recognition: Recent achievements and challenges
Abstract
Imidazo[4,5-f][1,10]phenanthroline (imidazo-phen) based metal complexes have been linked to extensive applications in diverse socio-economic research areas including chemosensors, organic light emitting devices (OLEDs), photochemistry and photobiology. Among the advantages of such systems, the photophysical characteristics can easily and finely be tuned either by substitution on various positions of the imidazo-phen moiety or with a change of the metal, and both these parameters may ultimately define the chemosensing properties for cations, anions and other important analytes. This review highlights the major and recent developments over the last 15 years in the field of luminescent anion sensing probes built on transition metal and lanthanide complexes involving imidazo-phen scaffolds; the latter notably distinguishes anion-responsive behaviors while referring to the alterations observed in different photophysical features of monometallic, homo- and hetero-bimetallic complexes reported to date, namely Ru(II), Os(II), Ir(III), Re(I) and Eu(III). The state of the art, knowledge gap, and the challenges outlined in the present study are expected to contribute as a rational design guideline tool for the relevant creation of novel anion-responsive luminescent metal based receptors.