Synthesis, Characterization and Solvatochromic Studies Using the Solvent Polarity Parameter, ENT on 2-Chloro-3-Ethylamino-1,4-Naphthoquinone

2017 ◽  
Vol 27 (4) ◽  
pp. 1505-1512 ◽  
Author(s):  
Arulappan Durairaj ◽  
Asir Obadiah ◽  
Subramanian Ramanathan ◽  
Princy Merlin Johnson ◽  
Antony Paulraj Bella ◽  
...  
Keyword(s):  
Solvent Polarity ◽  
Polarity Parameter

Determination of the empirical solvent polarity parameter ET(30) by multivariate image analysis

2013 ◽  
Vol 5 (4) ◽  
pp. 891-896 ◽  
Author(s):  
Fatemeh Shakerizadeh-Shirazi ◽  
Bahram Hemmateenejad ◽  
Abdol Mohammad Mehranpour
Keyword(s):  
Image Analysis ◽  
Solvent Polarity ◽  
Multivariate Image Analysis ◽  
Polarity Parameter ◽  
Multivariate Image

scholarly journals A fluorescent paramagnetic Mn metal–organic framework based on semi-rigid pyrene tetracarboxylic acid: sensing of solvent polarity and explosive nitroaromatics

IUCrJ ◽  
2015 ◽  
Vol 2 (5) ◽  
pp. 552-562 ◽  
Author(s):  
Alankriti Bajpai ◽  
Arindam Mukhopadhyay ◽  
Manchugondanahalli Shivakumar Krishna ◽  
Savitha Govardhan ◽  
Jarugu Narasimha Moorthy
Keyword(s):  
Metal Ions ◽  
Metal Organic Framework ◽  
Energy Charge ◽  
Fluorescence Emission ◽  
Solvent Polarity ◽  
Accessible Volume ◽  
Polarity Parameter ◽  
Metal Organic ◽  
Paramagnetic Metal ◽  
Organic Framework

An Mn metal–organic framework (Mn-MOF), Mn-L, based on a pyrene-tetraacid linker (H4L), displays a respectable fluorescence quantum yield of 8.3% in spite of the presence of the paramagnetic metal ions, due presumably to fixation of the metal ions in geometries that do not allow complete energy/charge-transfer quenching. Remarkably, the porous Mn-LMOF with ∼25% solvent-accessible volume exhibits a heretofore unprecedented solvent-dependent fluorescence emission maximum, permitting its use as a probe of solvent polarity; the emission maxima in different solvents correlate excellently with Reichardt's solvent polarity parameter (ETN). Further, the applicability of Mn-Lto the sensing of nitroaromaticsviafluorescence quenching is demonstrated; the detection limit for TNT is shown to be 125 p.p.m. The results bring out the fact that MOFs based on paramagnetic metal ions can indeed find application when the quenching mechanisms are attenuated by certain geometries of the organic linkers of the MOF.

The art of discovery in biophysical organic chemistry

2005 ◽  
Vol 83 (9) ◽  
pp. 1207-1211 ◽  
Author(s):  
Edward M Kosower
Keyword(s):  
Organic Chemistry ◽  
Solvent Effect ◽  
Charge Transfer Complex ◽  
Solvent Polarity ◽  
Physical Organic Chemistry ◽  
Stable Free Radical ◽  
Physical Organic ◽  
Polarity Parameter ◽  
Insight Into ◽  
Made In

Observations made in the course of experiments on pyridinium salts led to important discoveries in physical organic chemistry. The way in which the discoveries were made is likened to art rather than goal-directed "cold logic". We can describe the art of discovery as an effort enhanced by practice and intuition to recognize novelty in a finding and provide productive insight into its nature. We shall present some examples, and describe what happened after finding an unexpected light absorption band, a surprising solvent effect on spectra, and an unexpectedly stable and beautiful small organic radical.Key words: art of discovery, solvent polarity parameter, charge-transfer complex, stable free radical, solvent effect on spectra.

Solvent effect on the dipole moments and photo physical behaviour of 2,5-di-(5-tert-butyl-2-benzoxazolyl) thiophene dye

2013 ◽  
Vol 91 (12) ◽  
pp. 1107-1113 ◽  
Author(s):  
J.S. Kadadevarmath ◽  
G.H. Malimath ◽  
N.R. Patil ◽  
H.S. Geethanjali ◽  
R.M. Melavanki
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Dipole Moments ◽  
Emission Spectra ◽  
Solvent Polarity ◽  
Solvatochromic Shift ◽  
Shift Method ◽  
Tert Butyl ◽  
Solvatochromic Shift Method ◽  
Polarity Parameter

The absorption and emission spectra of fluorescent thiophene dye, namely, 2,5-di-(5-tert-butyl-2-benzoxazolyl) thiophene, have been recorded at room temperature in solvents of different polarities. The excited state dipole moments (μe) were estimated from Lippert’s, Bakhshiev’s, and Kawski–Chamma–Viallet’s equations using the variation of Stoke’s shift with the solvent dielectric constant and refractive index. The optimized geometry of the molecule and μg were calculated theoretically by Gaussian 03 software using B3LYP/6-31g* level of theory. The μg and μe were calculated by means of solvatochromic shift method and μe was determined in combination with μg. It was observed that μe were higher than those of the μg, indicating a substantial redistribution of the π-electron densities in a more polar excited state for the selected thiophene dye. Further, the change in the dipole moment (Δμ) was calculated both from solvatochromic shift method and on the basis of microscopic empirical solvent polarity parameter [Formula: see text] and values are compared.

Linear Free Energy Relationships. IV. Synthesis and Spectral Characterization of Some New Solvatochromics. N-(p-Substituted)benzyl-2′-hydroxy-4-stilbazolium Betaines

1975 ◽  
Vol 53 (14) ◽  
pp. 2162-2170 ◽  
Author(s):  
Harry W. Gibson ◽  
F. C. Bailey
Keyword(s):  
Transition Energy ◽  
Ph Dependence ◽  
Parent Compound ◽  
Solvent Polarity ◽  
Pyridyl Ring ◽  
Long Wavelength ◽  
Linear Free Energy ◽  
Polarity Parameter ◽  
Energy Relationships

The spectral data for the present series of compounds indicate that the long wavelength π → π* transition in each case involves transfer of negative charge from the phenol–quinone moiety to the pyridyl ring. Two separate features bear on this point: the transition energy dependence on (i) substituent and (ii) solvent. The plots of transition energy υs. Hammett substituent constant for the salts and the betaines have negative slopes as expected for such a transition. The plots of transition energy for the betaines υs. the solvent polarity parameter have large positive slopes, which are evidence for a large decrease in dipole moment upon excitation, consistent with such a transition. Through study of the pH dependence of the spectrum, the pKa of the parent compound was found to be 8.37 at 22°. From this pKa the apparent σortho for the N-benzylstilbazolium substituent was estimated to be 0.75.

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