scholarly journals Synthesis and fluorosolvatochromism of 3-arylnaphtho[1,2-b]quinolizinium derivatives

2016 ◽  
Vol 12 ◽  
pp. 854-862 ◽  
Author(s):  
Phil M Pithan ◽  
David Decker ◽  
Manlio Sutero Sardo ◽  
Giampietro Viola ◽  
Heiko Ihmels
Keyword(s):  
Hydrogen Bonding ◽  
Excited States ◽  
Solvent Polarity ◽  
Major Influence ◽  
Solvent Relaxation ◽  
Polar Solvents ◽  
Emission Energy ◽  
Arylboronic Acids ◽  
Photophysical Studies ◽  
A Charge

Cationic biaryl derivatives were synthesized by Suzuki–Miyaura coupling of 3-bromonaphtho[1,2-b]quinolizinium bromide with arylboronic acids. The resulting cationic biaryl derivatives exhibit pronounced fluorosolvatochromic properties. First photophysical studies in different solvents showed that the emission energy of the biaryl derivatives decreases with increasing solvent polarity. This red-shifted emission in polar solvents is explained by a charge shift (CS) in the excited state and subsequent solvent relaxation. Furthermore, the polarity of protic polar and aprotic polar solvents affects the emission energy to different extent, which indicates a major influence of hydrogen bonding on the stabilization of the ground and excited states.

CHAMELEON GROUND STATE AND EXCITED STATES OF EDT-TTF-IM-F4TCNQ RADICAL DYAD IN DIFFERENT ENVIRONMENTS

2012 ◽  
Vol 11 (03) ◽  
pp. 505-525 ◽  
Author(s):  
YUHUA ZHOU ◽  
KAI TAN ◽  
XIN LU
Keyword(s):  
Charge Transfer ◽  
Solid State ◽  
Excited States ◽  
Ground State ◽  
Density Functional ◽  
Solvent Polarity ◽  
Functional Study ◽  
Polar Solvents ◽  
Model Calculations ◽  
A Charge

We have performed a systematic density functional study on the ground-state electronic structure and excited states of a representative D-σ-A dyad, i.e. EDT-TTF-Im-F4TCNQ π-radical, in vacuo and in different conventional solvents (toluene, THF, DMF and DMSO) by using some popular hybrid density functionals (B3LYP, M05, M05-2X, PBE0 and BMK). It has been shown that the M05 and B3LYP functionals perform the best in predicting the intramolecular charge-transfer (ICT) pertaining to both the ground state and excited states of the dyad. The amphoteric dyad is liable to solvent-promoted ICT from its EDT-TTF-Im donor (D) to F4TCNQ acceptor (A), adopting a charge-unseparated ground state D-A• in vacuo, a partially zwitterionic ground state [D-A]• in nonpolar toluene solvent, and a fully zwitterionic ground state D•+-A- in such polar solvents as THF, DMF and DMSO. Owing to its solvent-dependent chameleon ground state, excited states of the dyad in solvents also exhibit remarkable dependence on solvent polarity, as revealed by TDDFT calculations. Furthermore, cluster model calculations revealed that intermolecular charge-transfer readily occurs between the dyads, accounting for the observed zwitterionic charge state in solid state and solid-state semiconductivity.

scholarly journals Photophysical Study of 1,5 – Diaminoanthraquinone in Different Solvents and at Various pH

2007 ◽  
Vol 4 (4) ◽  
pp. 523-530 ◽  
Author(s):  
P. Sivakumar ◽  
S. Kothai Nayaki ◽  
M. Swaminathan
Keyword(s):  
Hydrogen Bonding ◽  
Spectral Properties ◽  
Solvent Polarity ◽  
Dipolar Interactions ◽  
Solvent Relaxation ◽  
Polar Medium ◽  
Acidity Constants ◽  
Hydrogen Bonding Interactions ◽  
Photophysical Study ◽  
Stokes Shifts

The absorption and fluorescence spectral properties 1,5-diaminoanthraquinone (DAAQ) have been investigated in a series of organic solvents of different polarity and in aqueous solutions with Ho/ pH /H–in the range -10 to 17. The Stokes shifts of DAAQ are correlated with various solvent polarity scales. The better correlation of Stokes shifts of DAAQ with ET(30) indicates the predominance of hydrogen bonding interactions over dipolar interactions. The study also reveals that the fluorescence of DAAQ dication is red shifted on protonation. The abnormal fluorescence of DAAQ is found to be due to large solvent relaxation in polar medium. The acidity constants for various prototropic reactions in Soand S1states are determined and discussed.

Design, synthesis and photophysical studies of phenylethynyl-bridged phthalocyanine-fullerene dyads

2015 ◽  
Vol 19 (08) ◽  
pp. 934-945 ◽  
Author(s):  
Jaro Arero ◽  
Gerdenis Kodis ◽  
Robert A. Schmitz ◽  
Dalvin D. Méndez-Hernández ◽  
Thomas A. Moore ◽  
...  
Keyword(s):  
Excited States ◽  
Ground State ◽  
Photoinduced Electron Transfer ◽  
Spectroscopic Properties ◽  
Zinc Phthalocyanine ◽  
Triplet States ◽  
Free Base ◽  
Design Synthesis ◽  
Photophysical Studies ◽  
A Charge

A zinc and a free base phthalocyanine-fulleropyrrolidine dyad in which the chromophores are linked by a phenylethynyl group have been prepared using a new synthetic route, and their photoelectrochemical properties have been investigated. The zinc dyad is readily soluble in a variety of solvents, and its spectroscopic properties have been determined in toluene and benzonitrile. In toluene, excitation of the zinc phthalocyanine is followed by rapid establishment of an equilibrium between the phthalocyanine and fullerene excited states. These excited states decay mainly to the ground state and the respective triplet states. The fullerene triplet then transfers its energy to form the phthalocyanine triplet. About 20% of the phthalocyanine excited states lead to formation of a charge-separated state. In benzonitrile, the same decay pathways are observed, but photoinduced electron transfer is much faster, and generates the charge separated state with a quantum yield of ≥85%. The charge separated state has a lifetime of 2.8 ns in toluene and 94 ps in benzonitrile.

Excited States Dipole Moments and Fluorescence Behaviour of Some Derivatives of Dimethylaminobenzonitrile

1990 ◽  
Vol 45 (7) ◽  
pp. 883-888
Author(s):  
C. Brittinger ◽  
A. K. Maiti ◽  
W. Baumann ◽  
N. Detzer
Keyword(s):  
Dipole Moment ◽  
Excited State ◽  
Charge Transfer ◽  
Excited States ◽  
Intramolecular Charge Transfer ◽  
Dipole Moments ◽  
Solvent Polarity ◽  
Polar Solvents ◽  
Derivatives Of ◽  
Limiting Value

AbstractTwo sterically hindered derivatives of dimethylaminobenzonitrile (DMCA) have been synthesized and the dipole moment of their fluorescent excited state has been determined in differently polar solvents. Its value increases with solvent polarity up to a limiting value of (50 + 2.5) • 10-30 Cm. The results are discussed with reference to the twisted intramolecular charge transfer (TICT) state formation in the class of molecules related to DMCA.

HYDROGEN BONDING IN DIASTEREOISOMERIC α-β AMINOALCOHOLS: A REINVESTIGATION OF THE EPHEDRINES BY N.M.R

1960 ◽  
Vol 38 (1) ◽  
pp. 125-130 ◽  
Author(s):  
James B. Hyne
Keyword(s):  
Hydrogen Bonding ◽  
Polar Solvents ◽  
Relative Stabilities ◽  
Hydrogen Bonded

The results of an n.m.r. study of the diastereoisomeric ephedrine and ψ-ephedrine molecules in non-polar solvents are interpreted and discussed in terms of the relative stabilities of the intramolecularly hydrogen-bonded conformers.

Solvent, coordination and hydrogen-bond effects on the chromic luminescence of the cationic complex [(phen)(H2O)Re(CO)3]+

2016 ◽  
Vol 40 (7) ◽  
pp. 6451-6459 ◽  
Author(s):  
Pablo Mella ◽  
Karina Cabezas ◽  
Carla Cerda ◽  
Marjorie Cepeda-Plaza ◽  
German Günther ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Solvent Polarity ◽  
Cationic Complex ◽  
Unusual Behavior ◽  
Luminescence Emission

The unusual behavior of the solution luminescence emission of [(phen)(H2O)Re(CO)3]+(CF3SO3)− depends on the solvent polarity, and coordinating and hydrogen bonding ability.

STRUCTURAL AND SOLVENT EFFECTS ON THE n → π*(′U ← ′A) TRANSITIONS IN ALIPHATIC CARBONYL DERIVATIVES: EVIDENCE FOR HYPERCONJUGATION IN THE ELECTRONICALLY EXCITED STATES OF MOLECULES

1960 ◽  
Vol 38 (12) ◽  
pp. 2508-2513 ◽  
Author(s):  
C. N. R. Rao ◽  
G. K. Goldman ◽  
A. Balasubramanian
Keyword(s):  
Hydrogen Bonding ◽  
Carbonyl Group ◽  
Excited States ◽  
Solvent Effects ◽  
Electronically Excited States ◽  
Carbonyl Derivatives ◽  
Alkyl Groups ◽  
Electronically Excited

The n → π* transition of the carbonyl group has been studied in solvents of varying degree of polarity and hydrogen-bonding ability, in a number of aliphatic carbonyl derivatives. Evidence for hyperconjugation of the alkyl groups in the electronically excited states of molecules has been presented.

Hydrogen bonding properties of non-polar solvents

2010 ◽  
Vol 8 (6) ◽  
pp. 1455 ◽  
Author(s):  
Rafel Cabot ◽  
Christopher A. Hunter ◽  
Lisa M. Varley
Keyword(s):  
Hydrogen Bonding ◽  
Polar Solvents ◽  
Bonding Properties

scholarly journals Effects of Solvent Polarity on Solvation Free Energy, Dipole Moment, Polarizability, Hyperpolarizability and Molecular Properties of Metronidazole

2016 ◽  
Vol 19 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Mohammad Firoz Khan ◽  
Ridwan Bin Rashid ◽  
Md Yeunus Mian ◽  
Mohammad S Rahman ◽  
Mohammad A Rashid
Keyword(s):  
Free Energy ◽  
Dipole Moment ◽  
Gas Phase ◽  
Chemical Potential ◽  
Solvent Polarity ◽  
Solvation Free Energy ◽  
Molecular Properties ◽  
Chemical Hardness ◽  
Electrophilicity Index ◽  
Polar Solvents

A computational study of medium effect on solvation free energy, dipole moment, polarizability, hyperpolarizability and different molecular properties like chemical hardness & softness, chemical potential, electronegativity and electrophilicity index of metronidazole have been reported in this paper. Becke, 3-parameter, Lee-Yang-Parr (B3LYP) level of theory with 6-31G (d,p) basis set was applied for gas phase and solution. The effect of solvent polarity on solvation free energy, dipole moment, polarizability, hyperpolarizability and molecular properties were calculated by employing Solvation Model on Density (SMD). The solvation free energies and dipole moment of metronidazole were found to be increased in nonpolar to polar solvents. The dipole moment of metronidazole was higher in different solvent than that of the gas phase. Moreover, from non-polar to polar solvents the chemical potential, electronegativity and electrophilicity index were increased. On the other hand, opposite relation was found in the case of chemical hardness and softness. The results obtained in this study may lead to understand the stability and reactivity of metronidazole and the results will be of assistance to use the title molecule as reaction intermediates and pharmaceuticals.Bangladesh Pharmaceutical Journal 19(1): 9-14, 2016

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