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.

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.

Dithienothiophene fused 30π heptaphyrin and 34π octaphyrins: Syntheses, characterization and spectral properties

2020 ◽  
Vol 24 (01n03) ◽  
pp. 98-104
Author(s):  
Syamasrit Dash ◽  
Arindam Ghosh ◽  
Tavarekere K. Chandrashekar
Keyword(s):  
Hydrogen Bonding ◽  
Single Crystal ◽  
Spectral Properties ◽  
Nmr Spectrum ◽  
X Ray ◽  
Large Ring ◽  
H Nmr ◽  
Hydrogen Bonding Interactions ◽  
Protonated Forms

Syntheses of DTT fused 30[Formula: see text] heptaphyrin and 34[Formula: see text] octaphyrins are reported. The inclusion of fused group in the precursor itself allowed easy syntheses of these macrocycles. Fusion makes the macrocycles planar thus allowing strong [Formula: see text] electronic conjugation. Both 30[Formula: see text] heptaphyrin and 34[Formula: see text] octaphyrins are aromatic in freebase and protonated forms as revealed by large [Formula: see text] values in 1H NMR spectrum and sharp-intense Soret like bands in UV-vis spectrum. Interestingly one of the DTT ring undergoes fliping upon protonation in 34[Formula: see text] doubly fused octaphyrin. Such a large ring fliping is unprecedented in the literature. Single crystal X-ray analysis confirms planar nature of 34[Formula: see text] octaphyrins. Furthermore, the structure reveals two type of hydrogen bonding interactions: (a) CH[Formula: see text] (thiophene) and (b) CH[Formula: see text] (mesityl) leading to self assambled dimer separated by a distance of ∼3.0Å.

Theoretical study of hydrogen bonding interactions in substituted nitroxide radicals

2021 ◽  
Author(s):  
Thufail M. Ismail ◽  
Neetha Mohan ◽  
P. K. Sajith
Keyword(s):  
Hydrogen Bonding ◽  
Interaction Energy ◽  
Electrostatic Potential ◽  
Molecular Electrostatic Potential ◽  
Theoretical Study ◽  
Nitroxide Radicals ◽  
Hydrogen Bonding Interactions ◽  
Bonded Complexes ◽  
Hydrogen Bonded

Interaction energy (Eint) of hydrogen bonded complexes of nitroxide radicals can be assessed in terms of the deepest minimum of molecular electrostatic potential (Vmin).

scholarly journals Circular linkage of intramolecular multi-hydrogen bonding frameworks through nucleophilic substitutions of β-dicarbonyls onto cyanuric chloride and subsequent tautomerisation

RSC Advances ◽  
2020 ◽  
Vol 10 (64) ◽  
pp. 39033-39036
Author(s):  
Ayano Awatani ◽  
Masaaki Suzuki
Keyword(s):  
Hydrogen Bonding ◽  
Cyanuric Chloride ◽  
Nucleophilic Substitutions ◽  
Hydrogen Bonding Interactions ◽  
Triazine Derivatives

Triply β-dicarbonyl-embedded 1,3,5-triazine derivatives result in formation of circular linkage of resonance-assisted hydrogen bonding interactions, which can be regarded as well-delocalized resonance hybrids.

Selective Hydrogen Bonding Controls Temperature Response of Layer-by-Layer Upper Critical Solution Temperature Micellar Assemblies

Soft Matter ◽  
2021 ◽  
Author(s):  
Aliaksei Aliakseyeu ◽  
Victoria Albright ◽  
Danielle Yarbrough ◽  
Samantha Hernandez ◽  
Qing Zhou ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Methacrylic Acid ◽  
Temperature Response ◽  
Solution Temperature ◽  
Layer By Layer ◽  
Critical Solution Temperature ◽  
Hydrogen Bonding Interactions ◽  
Upper Critical Solution Temperature ◽  
Lbl Films

This work establishes a correlation between the selectivity of hydrogen-bonding interactions and the functionality of micelle-containing layer-by-layer (LbL) assemblies. Specifically, we explore LbL films formed by assembly of poly(methacrylic acid)...

scholarly journals Boosting Performance of Self-Polarized Fully Printed Piezoelectric Nanogenerators via Modulated Strength of Hydrogen Bonding Interactions

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1908
Author(s):  
Hai Li ◽  
Sooman Lim
Keyword(s):  
Hydrogen Bonding ◽  
Composite Film ◽  
High Performance ◽  
Composite Films ◽  
Β Phase ◽  
Hydrogen Bonding Interactions ◽  
Barium Titanate Nanoparticles ◽  
Surface Modified ◽  
Piezoelectric Devices ◽  
Piezoelectric Nanogenerators

Self-polarized piezoelectric devices have attracted significant interest owing to their fabrication processes with low energy consumption. Herein, novel poling-free piezoelectric nanogenerators (PENGs) based on self-polarized polyvinylidene difluoride (PVDF) induced by the incorporation of different surface-modified barium titanate nanoparticles (BTO NPs) were prepared via a fully printing process. To reveal the effect of intermolecular interactions between PVDF and NP surface groups, BTO NPs were modified with hydrophilic polydopamine (PDA) and hydrophobic 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) to yield PDA-BTO and PFD-BTO, respectively. This study demonstrates that the stronger hydrogen bonding interactions existed in PFD-BTO/PVDF composite film comparative to the PDA-BTO/PVDF composite film induced the higher β-phase formation (90%), which was evidenced by the XRD, FTIR and DSC results, as well as led to a better dispersion of NPs and improved mechanical properties of composite films. Consequently, PFD-BTO/PVDF-based PENGs without electric poling exhibited a significantly improved output voltage of 5.9 V and power density of 102 μW cm−3, which was 1.8 and 2.9 times higher than that of PDA-BTO/PVDF-based PENGs, respectively. This study provides a promising approach for advancing the search for high-performance, self-polarized PENGs in next-generation electric and electronic industries.

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