scholarly journals Sensitivity of the phenoxy derivatives of 2,4-dihydro-5H-[1,2,3]triazolo[4,5-d]pyrimidin-5-ones to acidic and basic stimuli

2021 ◽  
Vol 8 (3) ◽  
pp. 20210303
Author(s):  
Alexander K. Eltyshev ◽  
Nataliya P. Belskaya
Keyword(s):  
Spectral Data ◽  
Emission Intensity ◽  
Fluorescence Spectra ◽  
Sensory Response ◽  
Selective Detection ◽  
Acids And Bases ◽  
Derivatives Of

Herein we report the research on the sensitivity of six hydroxy derivatives of dihydrotriazolopyrimidines (HO-DTP) to acids and bases. The UV/Vis and fluorescence spectra of these compounds were investigated with the addition of the acids and bases. Spectral data revealed the strong red shifts for emission and absorption maxima in the presence of KOH and NaOH. Moreover, two DTPs demonstrated strengthening of the emission intensity. The obtained results and data published in our previous paper demonstrated the strong and selective sensory response of DTPs to the acids and bases and elucidated relationships between the structure and sensitivity to the environment. This finding allowed us to manage these properties by introducing the combination of substituents and functionalities into the heterocyclic core. Thus, investigations demonstrated the potential of the application of DTPs as chemo- and fluorosensors for selective detection of acids and bases.

scholarly journals New ent–Kaurane type Diterpene Glycoside, Pulicaroside-B, from Pulicaria Undulata L

2008 ◽  
Vol 3 (2) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Nasir Rasool ◽  
Viqar Uddin Ahmad ◽  
Naseem Shahzada ◽  
Muhammad A. Rashida ◽  
Aman Ullah ◽  
...  
Keyword(s):  
Spectral Data ◽  
Plant Extract ◽  
Soluble Fraction ◽  
2D Nmr ◽  
Spectroscopic Techniques ◽  
Spectral Evidence ◽  
Whole Plant ◽  
Derivatives Of ◽  
Related Compounds

Investigation of the n-butanol-soluble fraction of the whole plant extract of Pulicaria undulata yielded a new ent–kaurane type diterpene glycoside, pulicaroside-B (1), together with three known compounds, paniculoside-IV (2), roseoside (3), and corchoionol C (4). Compounds 3 and 4 are derivatives of α-ionol. The structures of the new and known compounds were elucidated by 1D- and 2D-NMR spectroscopic techniques, along with other spectral evidence, and by comparison of the spectral data with those of closely related compounds.

scholarly journals Phosphoreszenzeigensch aften von Methyl-, Chlor- und Brom-Derivaten des [2.2] Paracyclophans

1987 ◽  
Vol 42 (9) ◽  
pp. 1041-1042 ◽  
Author(s):  
H. Hopf ◽  
E. Hermann
Keyword(s):  
Triplet State ◽  
Fluorescence Spectra ◽  
Heavy Atom ◽  
The Other ◽  
Quantum Yields ◽  
Heavy Atom Effect ◽  
Chloro Derivatives ◽  
Derivatives Of ◽  
Atom Effect

Phosphorescence and fluorescence spectra, quantum yields of phosphorescence and fluorescence as well as phosphorescence lifetimes have been measured of six methyl-, chloro- and bromo-derivatives of [2.2] paracyclophane in ethanol at 77 K. While the chloro-derivatives as well as dibromo-paracyclophane exhibit a normal internal heavy-atom effect behaviour the momobromo-compound shows anomalies. These possibly indicate that in the monobromo-compound an additional pathway of the radiationless deactivation of the lowest triplet state is effective which does not occur with the other compounds.

scholarly journals The Effect of Some 3-Oxygen Functions on the Simmons–Smith Methylenation of 5,6-Unsaturated Steroids

1971 ◽  
Vol 49 (22) ◽  
pp. 3636-3641 ◽  
Author(s):  
J. F. Templeton ◽  
C. W. Wie
Keyword(s):  
Double Bond ◽  
Spectral Data ◽  
Ethyl Ether ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
Derivatives Of ◽  
Ethylene Acetal

The effect of 3α- and 3β-hydroxy, 3α- and 3β-acetoxy, 3-ethylene acetal, and 3α-methoxy derivatives of 5-cholestene on the addition of the Simmons–Smith reagent to the steroidal 5,6-double bond has been investigated. Reaction occurred only with epi-cholesterol to yield chiefly 3α-hydroxy-5,6α-cyclopropano-5α-cholestane. The 3α-ethyl ether, 3α-acetate, and a dialkoxymethane have been identified as byproducts. The p.m.r. and mass spectral data are given.

Selective Determination of Pentafluorobenzyl Ester Derivatives of Carboxylic Acids by GC Using Microwave Plasma and Mass Selective Detection

1991 ◽  
Vol 45 (10) ◽  
pp. 1617-1620 ◽  
Author(s):  
Jeffrey H. Brill ◽  
Bikshandarkoil A. Narayanan ◽  
John P. McCormick
Keyword(s):  
Carboxylic Acids ◽  
Microwave Plasma ◽  
Selective Detection ◽  
Capillary Gc ◽  
Selective Determination ◽  
Fragmentation Behavior ◽  
Microwave Induced Plasma ◽  
Characteristic Fragmentation ◽  
Derivatives Of

A highly selective, sensitive method for determination of carboxylic acids in water has been developed that is based on fluorine-selective gas chromatography (GC) detection of pentafluorobenzyl ester derivatives. The atmospheric-pressure helium microwave-induced plasma detector is well suited for fluorine-specific detection of these derivatives, which were well resolved by capillary GC and displayed a characteristic fragmentation behavior when examined by GC-mass selective detection. For demonstration purposes, a number of carboxylic acids, ranging from C1 to C20, were examined and found to be derivatized with yields greater than 90%, and a sample of creek water was examined for its carboxylic acid content.

Spectroscopic Studies of Dimethylamino Derivatives of Fluorene

2000 ◽  
Vol 55 (11-12) ◽  
pp. 902-908 ◽  
Author(s):  
J. Heldt ◽  
J. R. Heldt ◽  
T. Redzimski ◽  
H. Diehl ◽  
P. Schultz
Keyword(s):  
Dipole Moment ◽  
Excited State ◽  
Charge Transfer ◽  
Fluorescence Spectra ◽  
Intramolecular Charge Transfer ◽  
Stokes Shift ◽  
Spectroscopic Studies ◽  
Polar Solvents ◽  
Derivatives Of ◽  
Transfer State

Abstract 2-dimethylamino-9-fluorenol and 2-dimethylamino-9(4'dimethylamino)phenyl-9-fiuorenol in polar solvents in the excited state undergo conformation changes in which two fluorescent isomers are created. The isomers (in the local excited (LE) and charge transfer (CT) configuration) possess separate fluorescence bands, one appearing from the S1 (LE) state and the second from the intramolecular charge transfer state S1 (CT) of the neutral, aromatic molecule. Both bands show a solvatochromic effect. Using the method of the solvent induced Stokes shift of the absorption and fluorescence spectra the permanent dipole moment of the excited state of fluorene and its two derivatives have been determined. The dipole moment of the ground state and the Onsager cavity radius of the studied molecules were calculated with the Auestion Model 1 (AM1) program.

Magnetic anisotropy and phohotoluminescence properties of amorphous CexFeyOn nanowire arrays

2021 ◽  
pp. 2151016
Author(s):  
Fangkuo Wang ◽  
Xiao-You Yuan
Keyword(s):  
Magnetic Anisotropy ◽  
Emission Intensity ◽  
Anodic Aluminum Oxide ◽  
Fluorescence Spectra ◽  
Nanowire Arrays ◽  
Aao Template ◽  
Anodic Aluminum ◽  
Regular Change ◽  
Axis Parallel ◽  
Co Precipitation

Amorphous Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowire arrays with diameters about 100 nm were fabricated in porous anodic aluminum oxide (AAO) template channels by chemical co-precipitation assisted by suction filtration. Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowire arrays have distinct magnetic anisotropy behavior, and the axis parallel to the nanowire is magnetically “easy.” The magnetic properties of Ce[Formula: see text]Mn[Formula: see text]O[Formula: see text] and Ce[Formula: see text]Fe[Formula: see text]Mn[Formula: see text]O[Formula: see text] nanowire arrays were investigated to compare with Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowire arrays. The fluorescence spectra of Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowires arrays mixed with Eu, Tb, Sm showed that their emission intensity displays regular change with the increase of the mole fraction of mixture. The emission intensity reached maximum with increasing of Eu or Sm-mixing from 2 mol% to 10 mol% at 591 nm, 709 nm or 607 nm, then decreased gradually. However, there is no obvious influence to fluorescence of Tb mixed Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowire arrays, only one visible weak emission peak is present at 486 nm.

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