A Zn2+-responsive highly sensitive fluorescent probe and 1D coordination polymer based on a coumarin platform

Abstract

A coumarin-based Schiff base (receptor 1) exhibited fluorescence enhancement selectively with Zn(2+) at a nanomolar level in near-aqueous medium (EtOH-H2O; 1:1, v/v). The response was instantaneous with a detection limit of 3.26 × 10(-9) M. The sensing event is supposed to incorporate a combinational effect of intramolecular charge transfer (ICT), chelation-enhanced fluorescence (CHEF) and C[double bond, length as m-dash]N isomerization mechanisms. Various spectroscopic methods, viz. IR, UV-visible, fluorescence and NMR in association with single crystal XRD studies, were used for thorough investigation of the structure of receptor 1 as well as of the sensing event. The Zn(2+) complex of receptor 1 exhibited a very nice 1D chain coordination polymeric framework in its single crystal XRD.

Overview of the Antioxidant and Anti-Inflammatory Activities of Selected Plant Compounds and Their Metal Ions Complexes

“…Zn(II) complexes with coumarine substituted ligands are mainly six and five-coordinated: [Zn(Coum- O , N ,n)(Cl)](ClO 4 − ) 2 (CH 2 Cl 2 ) 4 [ 325 ], where substituted coumarins ligands are bound by phosphorus atom. Complex [Zn(Coum- O , N , O )(NO 3 )] [ 326 ] is polycyclic, while complex [Zn(Coum- O , N , O )] [ 327 ] is centrosymmetrical bis-complex with two tridentate ligands as well as [Zn(Coum- O , O )(H 2 O)] with two bidenate ligands. Five coordinated complexes: [Zn(Coum- O , N , O )(H 2 O)Cl] [ 328 ], [Zn(Coum- O , N , N )Cl 2 ] [ 329 ] have similar tridentate ligands and both have square pyramidal geometry.…”

A multichannel thiacalix[4]arene-based fluorescent chemosensor for Zn2+, F− ions and imaging of living cells

“…Moreover, it seems to affect the intramolecular charge transfer (ICT) within the sensor. 41,42 The electron-donating ability of the phenolic-OH group at one end and electron-withdrawing ability of carbonyl group at another end of coumarin ultimately resulted in a blue shift of the emission spectrum of 3. The fluorescence titration is shown in Fig.…”

Thiocarbazone‐appended coumarin: An easily accessible ratiometric fluorescent chemosensor for multianalyte (Zn2+ and Cu2+) systems

“…Coumarin derivatives have been used extensively as fluorescent chemosensors for the detection of metal ions because of their excellent fluorescence properties, such as high fluorescence quantum yield, long emission wavelengths and photostability. 11,12 Until now, a large number of fluorescent probes based on coumarin have been reported for the individual detection of Cu 2+11, [13][14][15][16][17][18][19][20][21][22] or Zn 2+12, [23][24][25][26][27][28][29][30][31][32][33][34][35] (Table 1). In general, the coordination of probes with Zn 2+ and Cu 2+ would enhance and quench the fluorescence due to the chelation-enhanced fluorescence (CHEF) effect of Zn 2+ ions 23,[26][27][28][29][30][31][32][33][34][35] and the paramagnetic of Cu 2+ ions, 17,19,21,22 respectively.…”