A novel compound 3-(4-(dimethylamino)phenyl)-1-(5-methyl-1-(naphthalen-1-yl)-1 H -1,2,3-triazol-4-yl)prop-2-en-1-one with intramolecular charge transfer characteristics was synthesized and characterized by 1 H NMR, 13 C NMR and X-ray crystallography. The ground state dipole moment and excited state dipole moment were estimated from solvatochromic methods using Bilot–Kawski, Lippert–Mataga, Bakhshiev's, Kawski–Chamma–Viallet and Reichardts correlations. The excited state dipole moment was found higher than ground state of molecule. Solute–solvent interactions were studied using multi-parameter solvent polarity scales proposed by Kamlet–Taft and Catalan. Effect of various metal ions on fluorescent behavior was also studied. It acts as a selective, sensitive and reversible fluorescent chemosensor for micromolar detection of Fe +3 ions. The linear range for this chemosensor was found to be 1 × 10 −7 to 1 × 10 −5  mol/L with detection limit of 42 μM. Binding stoichiometry and mechanism of Fe +3 ion detection was also investigated.

Determination of dipole moment, solvatochromic studies and application as turn off fluorescence chemosensor of new 3-(4-(dimethylamino)phenyl)-1-(5-methyl-1-(naphthalen-1-yl)-1H-1,2,3-triazol-4-yl)prop-2-en-1-one

Some fluorescent benzimidazole derivatives have been designed and synthesized using cobalt(ii) hydroxide as highly efficient catalyst. Synthesized compounds have been characterized by (1)H and (13)C-NMR and mass spectral analysis. The solvent effect on the absorption and fluorescence bands has been analyzed and supplemented by computational studies. Solvatochromic effects on the spectral position and profile of the stationary fluorescence spectra clearly indicate the charge transfer (CT) character of the emitting singlet states of all of the compounds studied in both polar and non-polar environments. The fluorescence decays for the benzimidazoles fit satisfactorily to a single exponential kinetics. HOMO and LUMO orbital pictures [DFT/B3LYP/6-31G(d,p)] evidence the existence of excited state intramolecular proton transfer (ESIPT) in benzimidazole derivatives containing a hydroxy group.

/pdf/synthesis-of-some-fluorescent-benzimidazole-derivatives-1rl1y34fon.pdf

Synthesis of some fluorescent benzimidazole derivatives using cobalt(II) hydroxide as highly efficient catalyst – spectral and physico-chemical studies and ESIPT process

The ligand N,N′-bis(pyridyl-2yl-methyl)ethylenediimine (PMEDI) was synthesized and then transformed into organic nanoparticles (ONPs) which were characterized by analytical methods. The ONPs were employed for the specific recognition of Zn 2+ in an aqueous medium by measuring the fluorescence intensity that increased with the concentration of Zn 2+ in the PMEDI solution. This proves that PMEDI-ONPs act as a chemo-sensor in detecting Zn 2+ at low concentration in aqueous medium. This chemo-sensor (ONPs) is able to determine the concentration of Zn 2+ ion in multi-vitamin formulations, and does so selectively for Zn 2+ in the presence of other nutrient metal ions. Apparently, photo induced electron transfer (PET) works in the PMEDI-ONPs when the fluorophore is excited. For [PMEDI-Zn] 2+ system, the PET is inhibited considerably by lowering the receptor HOMO energy due to the formation of a bond between the metal ion and the ligand. Due to inhibition of PET phenomenon the enhancement in the fluorescence emission of PMEDI-ONPs takes place. This is consistent with the theoretical study that the energy of the HOMO of the ligand is lowered when the [PMEDI-Zn] 2+ complex is formed.

Fluorescent organic nanoparticles (FONs) for the selective recognition of Zn2+: Applications to multi-vitamin formulations in aqueous medium

The development of a novel chemo-sensor for the detection of Al3+ with high sensitivity in aqueous solution is widely considered an important research goal because of the importance of such probes in medicine, living systems and the environment. In this work, we describe a new fluorescent probe, a Schiff's base N,N′-propylenebis(salicylimine) (salpn) as fluorescent organic nanoparticles for Al3+. The study shows that salpn detects Al3+ with the detection limit as low as 1.24 × 10−3 mM, indicating that the chemo-sensor has high sensitivity in aqueous medium, and the fluorescence intensity increases with the increasing Al3+ concentration in the presence of the salpn-ONPs which act as chemo-sensors. The interference of common coexistent metal ions such as Mn2+, Mg2+, Co2+, Fe3+, Ni2+, Zn2+, Sr2+, Ag+, Sm3+, Al3+, Cd2+, Ba2+, Na+ and K+ was tested, showing that salpn-ONPs efficiently detect Al3+ ions with small interference from Cu2+ and Cr3+. Finally, the efficiency of salpn to as a fluorescent probe for Al ion in living systems was evaluated in Gram-negative and Gram positive bacteria, and con-focal laser scanning microscopy confirms its utility that this chemo-sensor efficiently detects Al3+ ion in Staphylococcus aureus enclosed by a single membrane.

Fluorescent organic nanoparticles (FONs) for selective recognition of Al3+: application to bio-imaging for bacterial sample

Synthesis, spectral studies and solvatochromism of some novel benzimidazole derivatives--ESIPT process.

Potential fluorescent chemosensor based on L-tryptophan derivative: DFT based ESIPT process.

DFT based ESIPT process of luminescent chemosensor: Taft and Catalan solvatochromism.

Theoretical structural analysis (FT-IR, FT-R), solvent effect on electronic parameters NLOf, FMO, NBO, MEP, UV (IEFPCM model), Fukui function evaluation with pharmacological analysis on methyl nicotinate

Theoretical spectroscopic electronic elucidation with different solvents (IEFPCM model), biological assessment and molecular docking studies on Moroxydine-Antiviral drug agent

The thermal degradation of N -(salicylidene)- L -leucine was studied under non-isothermal conditions in air atmosphere. For kinetic analysis, the TG/DTA/DTG data obtained at three different heating rates were processed by Friedman, Kissinger-Akahira-Sunose, Flynn-Wall-Ozawa and Kissinger methods. The analysis indicates a complex reaction process which can be best described by the three dimensional (Ginstling-Brounshtein) model D4.

/pdf/thermal-decomposition-of-n-salicylidene-l-leucine-in-static-1dr5q1ez7i.pdf

Munusamy Vennila

Papers

Potential fluorescent chemosensor based on L-tryptophan derivative: DFT based ESIPT process.

DFT based ESIPT process of luminescent chemosensor: Taft and Catalan solvatochromism.

Theoretical structural analysis (FT-IR, FT-R), solvent effect on electronic parameters NLOf, FMO, NBO, MEP, UV (IEFPCM model), Fukui function evaluation with pharmacological analysis on methyl nicotinate

Theoretical spectroscopic electronic elucidation with different solvents (IEFPCM model), biological assessment and molecular docking studies on Moroxydine-Antiviral drug agent

Thermal decomposition of N-(salicylidene)-L-leucine in static air atmosphere