Diganta Kumar Das

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N,N,N,N-tetradentate macrocyclic ligand (L) has been synthesized by the condensation of benzil and semicarbazide and characterized. On excitation by light of wavelength 350 nm, L exhibited a fluorescent peak at λmax = 454 nm, which showed ca 6 times enhancement in intensity with a blue shift on interaction with Zn2+. L has been found to act as a selective(More)
The simple Schiff base (Z)-N-benzylidenenaphthalen-1-amine (L) acts as an effective fluorescence sensor for Al(3+) by "off-on" mode, and ca. 42 times enhancement in fluorescence intensity is observed. The detection limit of L towards Al(3+) is observed to be 5 × 10(-5) M. UV/Visible and fluorescence data as well as DFT calculations confirm 1:3 coordination(More)
The fluorescence intensity of salicylaldehyde phenylhydrazone (L), in 1:1 (v/v) CH3OH:H2O was enhanced by ca. 100 times with a blue shift in emission maximum, on interaction with Pb2+ ion. No enhancement in fluorescent intensity of L was observed on interaction with metal ions - Na+, K+, Ca2+, Cu2+, Ni2+, Zn2+, Cd2+ and Hg2+. This signal transduction was(More)
Schiff base derived from naphthylamine and benzil (L) binds to two Cu(2+) ions, one by coordination through N of the Schiff base and another by pi cation interaction through benzil rings. This bonding pattern determined by DFT calculation has been proved by matching electronic spectrum obtained from TDDFT calculation to the experimental one. L acts as(More)
Condensation product (L) of salicylaldehyde and semicarbazide behaves as a fluorescent sensor for Cd2+ ion, in 1:1 DMSO:H2O, over Mn2+, Fe2+, Ni2+, Co2+, Cu2+, Pb2+ and Hg2+ ions. The emission peak of L at λmax = 520 nm, on excitation with 420 nm wavelength photons, showed an enhancement in intensity of ca 60-fold when interacted with Cd2+ ion. The(More)
The proton equilibrium in aqueous surfactant solutions of hemin, (PPIX)Fe(H2O)+2, involving the propionic acid groups is reported (PPIX = protoporphyrinato IX). The surfactant used are sodium dodecyl sulphate (SDS), triton X-100 (TX-100) and hexadecyl trimethylammonium bromide (CTAB). The pKa values, determined spectroscopically from the pH variations of(More)
Single molecule acting as both fluorescent and electrochemical sensor for Zn(2+) ion is rare. The product (L) obtained on condensation between benzil and L-tryptophan has been characterized by H NMR, ESI-MS and FT-IR spectroscopy. L in 1:1 (v/v) CH3OH:H2O solution shows fluorescence emission in the range 300 nm to 600 nm with λmax at 350 nm when is excited(More)
The condensation product of L-alanine and salicylaldehyde was synthesised and characterised which was found to be selective fluorescent “on” sensor for Al3+ ion with the detection limit 10−6 M. The sensor is free of interferences from metal ions - Na+, K+, Ca2+, Mn2+, Co2+, Ni2+, Cu2+, Pb2+, Cd2+, Hg2+ and Fe3+. The Fluorescence and the UV/visible spectral(More)
Imbalance of zinc ion (Zn2+) in human body causes diseases like Alzheimer’s and Parkinson’s and therefore Zn2+ estimation in biological fluids has diagnostic values. Fluorescence “off-on” sensors have advantages of high sensitivity and in situ application over other sensors. A new fluorescent “off-on” Zn2+ sensor, N-benzoate-N′ salicylaldehyde(More)
A new fluorescent probe for Mn2+ ion, (6E)-N-((E)-1,2-diphenyl-2-(pyridin-2-ylimino)ethylidene)pyridin-2-amine (L), has been synthesized from benzil and 2-amino pyridine and characterized. In 1:1 (v/v) CH3CN:H2O (pH 4.0, universal buffer) L exhibits fluorescent intensity with emission peak at λmax 360 nm on excitation with photons of 310 nm. Fluorescent(More)