Imran Khan Raihana | Madurai Kamaraj University, Madurai, Tamil Nadu, INDIA (original) (raw)

Uploads

Papers by Imran Khan Raihana

Research paper thumbnail of A pyridinium modified β-cyclodextrin: an ionic supramolecular ligand for palladium acetate in C–C coupling reactions in water

Green Chemistry, 2016

An ionic Pd(ii) complex stabilized by a water soluble pyridinium modified β-cyclodextrin was prep... more An ionic Pd(ii) complex stabilized by a water soluble pyridinium modified β-cyclodextrin was prepared and characterized by NMR, mass spectrometry, FT-IR spectroscopy, UV-visible spectroscopy and DLS (dynamic light scattering).

Research paper thumbnail of β-Cyclodextrin included coumarin derivatives as selective fluorescent sensors for Cu2+ ions in HeLa cells

RSC Advances, 2016

A highly sensitive and selective fluorescent sensor for Cu2+ ions in water medium is reported usi... more A highly sensitive and selective fluorescent sensor for Cu2+ ions in water medium is reported using 4-((benzo[d]thiazol-2-ylthio)methyl)-5,7-dihydroxy-2H-chromen-2-one (1) included β-cyclodextrin, as a probe.

Research paper thumbnail of Isolation of biochanin A, an isoflavone, and its selective sensing of copper(II) ion

Sensors and Actuators B: Chemical, 2015

Biochanin A (BnA) a natural o-methylated isoflavone, is isolated from the leaves of Eupatorium ad... more Biochanin A (BnA) a natural o-methylated isoflavone, is isolated from the leaves of Eupatorium adenaphorum and is effectively utilized as a sensor probe for copper ion with good selectivity and sensitivity. The effect with the presence of other metal ions is also investigated and BnA is found to be selective towards Cu 2+ ion over other metal ions such as Zn

Research paper thumbnail of Pyridinium Modified β-Cyclodextrin: An Ionic Supramolecular Ligand for Palladium acetate in C-C Coupling Reactions in Water

An ionic Pd(II) complex stabilized by water soluble pyridinium modified βcyclodextrin was prepare... more An ionic Pd(II) complex stabilized by water soluble pyridinium modified βcyclodextrin was prepared and characterized by NMR, Mass spectrometry, FT-IR spectroscopy, UV-Visible spectroscopy and DLS (dynamic light scattering). The resulting Pd(II)@Pyr:β-CD complex showed very good catalytic activity in Suzuki-Miyaura and Heck C-C coupling reactions in an environmentally benign water medium. Good to excellent yields were obtained for the coupling of various aryl halides including chlorides with phenylboronic acid/styrene using a catalytic amount of Pd(II)@Pyr:β-CD. This homogeneous catalyst can be reused and recycled more than six times with only marginal loss in its catalytic activity.

Research paper thumbnail of Isolation of biochanin A, an isoflavone, and its selective sensing of copper(II) ion

Biochanin A (BnA) a natural o-methylated isoflavone, is isolated from the leaves of Eupatorium ad... more Biochanin A (BnA) a natural o-methylated isoflavone, is isolated from the leaves of Eupatorium adenaphorum and is effectively utilized as a sensor probe for copper ion with good selectivity and sensitivity. The effect with the presence of other metal ions is also investigated and BnA is found to be selective towards Cu 2+ ion over other metal ions such as Zn 2+ , Sn 2+ , Ni 2+ , Ag + , Bi 2+ , Pb 2+ , Co 3+ , In 3+ , Mn 2+ , Fe 2+ , Li + , Hg 2+ and Ca 2+ at pH 7.1 with a detection limit upto 1.0 × 10 −6 mol L −1 . The sensor probe BnA exhibits selective fluorescence quenching via an intramolecular charge transfer (ICT) upon addition of Cu 2+ . The proposed mechanism is strongly supported by TD-DFT calculations and the 1:1 complex (BnA-Cu 2+ ) formation is confirmed by ESI-MS and Job's plot.

Research paper thumbnail of β-Cyclodextrin Included Coumarin Derivatives as Selective Fluorescent Sensors for Cu 2+ Ions in HeLa Cells

A highly sensitive and selective fluorescent sensor for Cu 2+ ion in water medium is reported usi... more A highly sensitive and selective fluorescent sensor for Cu 2+ ion in water medium is reported using 4-((benzo[d]thiazol-2ylthio)methyl)-5,7-dihydroxy-2H-chromen-2-one (1) included β-cyclodextrin, as probe. The fluorogenic supramolecule has displayed good selectivity and affinity towards Cu 2+ ions over other cations after examining in biological systems having intracellular Cu 2+ ions, especially in cultured HeLa cells using fluorescence microscopic imaging. The lowest detection limit of Cu 2+ ions observed using this probe is as low as 2.52×10 -10 M. The observed on-off fluorescence with the periodic addition of Cu 2+ ion is explained via an Intramolecular Charge Transfer mechanism (ICT) and the inclusion of 1 in βcyclodextrin is characterised by 1 H-NMR molecular modeling studies. The results show that the present β-CD:1 system, studied in HeLa cells, can be potentially used in monitoring the biological functions of Cu 2+ ions.

Research paper thumbnail of A pyridinium modified β-cyclodextrin: an ionic supramolecular ligand for palladium acetate in C–C coupling reactions in water

Green Chemistry, 2016

An ionic Pd(ii) complex stabilized by a water soluble pyridinium modified β-cyclodextrin was prep... more An ionic Pd(ii) complex stabilized by a water soluble pyridinium modified β-cyclodextrin was prepared and characterized by NMR, mass spectrometry, FT-IR spectroscopy, UV-visible spectroscopy and DLS (dynamic light scattering).

Research paper thumbnail of β-Cyclodextrin included coumarin derivatives as selective fluorescent sensors for Cu2+ ions in HeLa cells

RSC Advances, 2016

A highly sensitive and selective fluorescent sensor for Cu2+ ions in water medium is reported usi... more A highly sensitive and selective fluorescent sensor for Cu2+ ions in water medium is reported using 4-((benzo[d]thiazol-2-ylthio)methyl)-5,7-dihydroxy-2H-chromen-2-one (1) included β-cyclodextrin, as a probe.

Research paper thumbnail of Isolation of biochanin A, an isoflavone, and its selective sensing of copper(II) ion

Sensors and Actuators B: Chemical, 2015

Biochanin A (BnA) a natural o-methylated isoflavone, is isolated from the leaves of Eupatorium ad... more Biochanin A (BnA) a natural o-methylated isoflavone, is isolated from the leaves of Eupatorium adenaphorum and is effectively utilized as a sensor probe for copper ion with good selectivity and sensitivity. The effect with the presence of other metal ions is also investigated and BnA is found to be selective towards Cu 2+ ion over other metal ions such as Zn

Research paper thumbnail of Pyridinium Modified β-Cyclodextrin: An Ionic Supramolecular Ligand for Palladium acetate in C-C Coupling Reactions in Water

An ionic Pd(II) complex stabilized by water soluble pyridinium modified βcyclodextrin was prepare... more An ionic Pd(II) complex stabilized by water soluble pyridinium modified βcyclodextrin was prepared and characterized by NMR, Mass spectrometry, FT-IR spectroscopy, UV-Visible spectroscopy and DLS (dynamic light scattering). The resulting Pd(II)@Pyr:β-CD complex showed very good catalytic activity in Suzuki-Miyaura and Heck C-C coupling reactions in an environmentally benign water medium. Good to excellent yields were obtained for the coupling of various aryl halides including chlorides with phenylboronic acid/styrene using a catalytic amount of Pd(II)@Pyr:β-CD. This homogeneous catalyst can be reused and recycled more than six times with only marginal loss in its catalytic activity.

Research paper thumbnail of Isolation of biochanin A, an isoflavone, and its selective sensing of copper(II) ion

Biochanin A (BnA) a natural o-methylated isoflavone, is isolated from the leaves of Eupatorium ad... more Biochanin A (BnA) a natural o-methylated isoflavone, is isolated from the leaves of Eupatorium adenaphorum and is effectively utilized as a sensor probe for copper ion with good selectivity and sensitivity. The effect with the presence of other metal ions is also investigated and BnA is found to be selective towards Cu 2+ ion over other metal ions such as Zn 2+ , Sn 2+ , Ni 2+ , Ag + , Bi 2+ , Pb 2+ , Co 3+ , In 3+ , Mn 2+ , Fe 2+ , Li + , Hg 2+ and Ca 2+ at pH 7.1 with a detection limit upto 1.0 × 10 −6 mol L −1 . The sensor probe BnA exhibits selective fluorescence quenching via an intramolecular charge transfer (ICT) upon addition of Cu 2+ . The proposed mechanism is strongly supported by TD-DFT calculations and the 1:1 complex (BnA-Cu 2+ ) formation is confirmed by ESI-MS and Job's plot.

Research paper thumbnail of β-Cyclodextrin Included Coumarin Derivatives as Selective Fluorescent Sensors for Cu 2+ Ions in HeLa Cells

A highly sensitive and selective fluorescent sensor for Cu 2+ ion in water medium is reported usi... more A highly sensitive and selective fluorescent sensor for Cu 2+ ion in water medium is reported using 4-((benzo[d]thiazol-2ylthio)methyl)-5,7-dihydroxy-2H-chromen-2-one (1) included β-cyclodextrin, as probe. The fluorogenic supramolecule has displayed good selectivity and affinity towards Cu 2+ ions over other cations after examining in biological systems having intracellular Cu 2+ ions, especially in cultured HeLa cells using fluorescence microscopic imaging. The lowest detection limit of Cu 2+ ions observed using this probe is as low as 2.52×10 -10 M. The observed on-off fluorescence with the periodic addition of Cu 2+ ion is explained via an Intramolecular Charge Transfer mechanism (ICT) and the inclusion of 1 in βcyclodextrin is characterised by 1 H-NMR molecular modeling studies. The results show that the present β-CD:1 system, studied in HeLa cells, can be potentially used in monitoring the biological functions of Cu 2+ ions.