Signaling preferences of substituted pyrrole coupled six-membered rhodamine spirocyclic probes for Hg²⁺ion detection

Abstract

Two six-membered spirocyclic rhodamine derivatives containing substituted pyrroles (1 and 2) were shown to exhibit preferential dual mode 'turn-on' signaling responses in the presence of Hg(2+) ions through complexation mediated spiro-ring opening. Although the rate of spiro-ring opening mediated through complexation is much slower in these probes in comparison to their five membered analogues, they exhibited a comparable sensitivity in metal ion detection.

A Novel Ratiometric Fluorescent Probe for Mercury (II) ions and Application in Bio-imaging

“…Compared with these analytical methods, fluorescent techniques have been a promising bio-imaging technique in fields of life sciences, environmental monitoring, and disease diagnosis for their excellent performance targeting metal ions with low cost, good biocompatibility, high sensitivity, selectivity and real-time imaging. Some fluorescent probes have been designed for recognition of Hg 2+ ions in recent years [19,20,21,22,23,24,25], most of which utilize general fluorophores as signal-output groups such as BODIPY, 1,8-napthalimide, cyanine, coumarin, fluorescein, pyrene, anthracene, and rhodamine etc. [26].…”

New Six-Membered pH-Insensitive Rhodamine Spirocycle in Selective Sensing of Cu2+through C–C Bond Cleavage and Its Application in Cell Imaging

“…The expansion of spirocycle improves the stability and selectivity of the chemosensors in sensing of metal ions. Only four kinds of examples are known till today where either the thiourea ( R1 and R2 ), , hydrazine amide ( R3 ) or the pyrrole-based ( R4 and R5 ) six-membered spiro rings are involved in sensing of bio-relevant metal ions such as Cu 2+ and Hg 2+ by ensuing the cleavage of the C–N bond in the spirocycle (Chart ). In this context, the existing five-membered rhodamine chemosensors are also known to interplay via C–N bond cleavage.…”

Detection and Removal of Metal Ion based on a Fluorescent Sensor Composed of a Photoresponsive Rhodamine Derivative by Host-Gust Interaction

“…Therefore, selective and sensitive detection of Hg 2+ , which is very important in solving physiological and environmental problems, has attracted much attention due to increasing concerns of environmental protection . Fluorescent spectrophotometry is an important technique to detect metal ions owing to its distinct advantage of facile detection, high sensitivity, and easy tenability . Among the fluorescent sensors, the rhodamine scaffold is an ideal template chromophore for the construction of metal chemosensors because they have large molar extinction coefficients, long excitation and emission wavelengths, and high fluorescence quantum yields .…”

“…The chemosensors displayed great brightness and fluorescence enhancement with low limit of detection following metal coordination because of the redox property of the ferrocene/ferrocenium couple. Bag et al . prepared six‐membered spirocyclic rhodamine derivatives containing substituted pyrroles for response in the presence of Hg 2+ ions through complex mediated spiro‐ring opening.…”