An acid catalyzed reversible ring-opening/ring-closure reaction involving a cyano-rhodamine spirolactam

Abstract

Q. (2013). An acid catalyzed reversible ring-opening/ring-closure reaction involving a cyano-rhodamine spirolactam.

Exclusive Detection of Sub‐Nanomolar Levels of Palladium(II) in Water: An Excellent Probe for Multiple Applications

“…[16] The effect of pH value on the sensing process was studied by using different buffer solutions with various pH values (HCO 2 Na/HCl buffer for pH 2-4.5, CH 3 CO 2 Na/HCl buffer for pH 5-6.5, Tris/HCl for pH 7-9, Na 2 B 4 O 7 ·10 H 2 O/NaOH for pH [10][11][12]. The solutions of PdCl 2 , [PdA C H T U N G T R E N N U N G (PPh 3 ) 2 Cl 2 ], PdA C H T U N G T R E N N U N G (OAc) 2 , and PtCl 2 were prepared according to literature procedures.…”

“…[7] Various analytical methods, such as atomic absorption spectroscopy, X-ray fluorescence spectroscopy, and plasma emission spectroscopy, have long been used to detect various ions and analytes, even at sub-micromolar concentrations. [10] Three procedures have mainly been exploited for the detection of palladium. To overcome these difficulties, over the past few years, there has been increasing focus on the design and synthesis of various small-molecule-based probes that can detect Pd by using simple UV/Vis and fluorescence spectrophotometry.…”

“…[10] However, most of the reported rhodamine-based sensors pose serious drawbacks, including prolonged incubation time, responses only in organic or organic/water mixtures, potential interference with other PGE ions, and no discrimination between Pd II and Pd 0 . Moreover, their facile synthesis and highly sensitive photophysical properties contribute to their frequent application.…”

A highly selective ratiometric fluorescent pH probe based on a PAMAM wavelength-shifting bichromophoric system

“…Because of their excellent fluorescence properties and good photostability, 1,8-naphthalimide dyes were used extensively in a number of areas, including chemosensing materials [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]. On the basis of the spirolactam (non-fluorescent) to ring-open amide (fluorescent) equilibrium of rhodamine, series of rhodamine-based dyes with excellent ''off-on'' switching of fluorescence upon encountering the correct target have been synthesized [44][45][46][47].…”

Synthesis and studies of two proton–receptor fluorescent probes based on 1,8‐naphthalimide

“…Some of these probes have worked well in the neutral pH range of 6–8 , while others have displayed optimal working conditions in the weakly acidic pH range of 4–6 . Very few probes respond to a pH value below 4 , and their p K a values are below 2.5, which are suitable for extremely acidic conditions . Hence, there is a need for the development of probes that could detect a pH value of 4 and even 3.…”