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61.
Some novel Y-shaped imidazole derivatives were developed and characterized by NMR and mass spectral techniques. The photophysical
properties of these imidazole derivatives were studied in several solvents. The Kamlet-Taft and Catalan’s solvent scales were
found to be the most suitable for describing the solvatochromic shifts of the absorption and fluorescence emission. The adjusted
coefficient representing the electron releasing ability or basicity of the solvent, C
β
or C
SB has a negative value, suggesting that the absorption and fluorescence bands shift to lower energies with the increasing electron-donating
ability of the solvent. This effect can be interpreted in terms of the stabilization of the resonance structures of the chromophore.
The observed lower fluorescence quantum yield may be due to an increase in the non-radiative deactivation rate constant. This
is attributed to the loss of planarity in the excited state provided by the non co-planarity of the cinnamaldehyde ring attached
to C(2) atom of the imidazole ring. Such a geometrical change in the excited state leads to an important Stokes shift, reducing
the reabsorption and reemission effects in the detected emission in highly concentrated solutions. 相似文献
62.
Jayaraman Jayabharathi Venugopal Thanikachalam Marimuthu Venkatesh Perumal 《Journal of luminescence》2012,132(3):707-712
The interaction between the imidazole derivative 2-(2,4-difluorophenyl)-1-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline (dfppip) and bovine serum albumin (BSA) was investigated by fluorescence and UV–vis absorbance spectroscopy. From the experimental results, it was found that the imidazole derivative has strong ability to quench the intrinsic fluorescence of BSA by forming complexes. Electrostatic interactions play an important role to stabilize the complex. The binding constants and the number of binding sites have been determined in detail. The distance (r) between the donor and the acceptor was obtained according to fluorescence resonance energy transfer (FRET). Conformational changes of BSA were observed from synchronous fluorescence spectroscopy. The effect of metal ions such as Cu2+, Zn2+, Ca2+, Mg2+, Ni2+, Co2+ and Fe2+ on the binding constants between the imidazole derivative and BSA were also studied. 相似文献
63.
Selvarangam E. Kiruthika Rangarajan Amritha Paramasivan T. Perumal 《Tetrahedron letters》2012,53(26):3268-3273
A facile strategy for the synthesis of functionalized spirolactones from isatin, primary amines, and activated alkynes through Huisgen dipolar additions are discussed. A novel route for the formation of dispirodihydrofuranyl oxindoles from activated cyclic electrophiles, amines, and DMAD has also been developed. This method offers several advantages like high yield, readily available starting materials, and involves less hazardous chemical techniques. 相似文献
64.
65.
Hoong‐Kun Fun R. Sankaranarayanan D. Velmurugan S. Shanmuga Sundara Raj G. Babu P. T. Perumal 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):475-476
In the title compound, C26H22N2O2S, the tetrahydropyridine ring has a conformation intermediate between half‐chair and sofa. The tetrahydroquinoline mean plane makes a dihedral angle of 73.3 (1)° with the cyclopentene ring, which adopts an envelope conformation, and an angle of 45.45 (4)° with the indole best plane. The dihedral angle between the benzene and pyrrole rings is 2.6 (1)°. The orientations of the phenyl ring on the sulfonyl group and of the indole are governed by weak C—H?O interactions. The packing of the molecule in the solid state is stabilized by C—H?O and C—H?N hydrogen bonds. 相似文献
66.
Perumal Gobinath Ponnusamy Packialakshmi Ali Daoud Saud Alarifi Akbar Idhayadhulla Surendrakumar Radhakrishnan 《Molecules (Basel, Switzerland)》2020,25(24)
In this study, the synthesis of one-pot 10-phenyl-3,4,6,7-tetrahydro-1H-spiro [acridine-9,2′-indoline]-1,3,8-trione derivatives was achieved via a four-component cyclocondensation reaction, which was carried out in solvent-free conditions, and using p-toluenesulfonic acid (p-TSA) as a catalyst. The product was confirmed by FT-IR, 1H-NMR, 13C-NMR, mass spectra, and elemental analysis. Furthermore, the anticancer activity was screened for all compounds. Among these compounds, compound 1c was more effective (GI50 0.01 µm) against MCF-7 cancer cell lines than standard and other compounds. Therefore, the objective of this study was achieved with a few promising molecules having been demonstrated to be potential anticancer agents. 相似文献
67.
Perumal Rajakumar 《Tetrahedron》2003,59(28):5373-5376
BINOL based electron rich chiral cyclophanes possessing large cavities have been synthesized starting from m-terphenyl dibromide and methyl m-/p-cinnamate. The presence of double bonds in the chiral cyclophanes makes them electron rich as revealed by C-T complexation studies of such cyclophanes donors with guests like TCNE, TCNQ and DDQ. 相似文献
68.
The synthesis is described of various 4-substituted ( 1 ) and 4,6-disubstituted ( 2 ) dibenzothiophenes by lithiation reactions. The factors controlling the formation of 4,6-disubstituted dibenzothiophenes by the lithiation of 4-methyl- and 4-ethyl-dibenzothiophene at the 6-position versus lithiation at the α-carbon of the 4-substituent are examined. 相似文献
69.
Gopinath Subash C. B. Perumal Veeradasan Balakrishnan S.R. Md Arshad M. K. Lakshmipriya Thangavel Haarindraprasad R. Hashim Uda 《Mikrochimica acta》2017,184(11):4425-4431
Microchimica Acta - The authors describe an impedimetric nanosensor for aptamer-mediated detection of ATP. A triangular junction of polysilicon substrate is used as a transducer. The aptamer was... 相似文献
70.
In the present study, we report a recyclable, nanocrystalline CdS thin film mediated efficient one‐pot, three component synthesis of Hantzsch 1, 4 Dihydropyridine in good yields. The catalyst is also effective for the efficient synthesis of Polyhydroquinoline and 1, 8‐dioxodecahydroacridine derivatives in good to excellent yields. The CdS thin film catalyst was prepared by chemical bath deposition (CBD) technique. The cadmium sulphide thin film was characterized by powder XRD and FT‐IR studies. The average crystallite size (D) was calculated from powder XRD by using Scherrer formula and SEM analysis. The elemental composition of the CdS thin film was established by EDS analysis. The effect of temperature, substituent's, catalyst loading and mole ratio on the reaction was also studied. All the products were thoroughly characterized by 1H‐NMR, 13C‐NMR, FT‐IR, Mass spectral and CHN analysis. A plausible mechanism for the CdS thin film catalyzed synthesis of 1, 4 DHP's is proposed. The heterogeneous catalyst could be easily recovered from the reaction mixture and successively reused at least five times without loss of activity. 相似文献