Mechanism of Concerted Hydrogen Bond Reorientation in Clathrates of Dianin’s Compound and Hydroquinone

2011 ◽  
Vol 133 (46) ◽  
pp. 18880-18888 ◽  
Author(s):  
Alexandra Nemkevich ◽  
Mark A. Spackman ◽  
Ben Corry
Keyword(s):  
Hydrogen Bond ◽  
Dianin's Compound

scholarly journals 4-(4-Hydroxyphenyl)-2,2,4-trimethyl-7,8-benzothiachroman, a fused-ring counterpart ofthia-Dianin's compound

2017 ◽  
Vol 73 (11) ◽  
pp. 1662-1665 ◽  
Author(s):  
Christopher S. Frampton ◽  
Joseph J. McKendrick ◽  
David D. MacNicol
Keyword(s):  
Hydrogen Bond ◽  
Title Compound ◽  
Monoclinic Space Group ◽  
Methyl Group ◽  
Space Group ◽  
Compound C ◽  
Fused Ring ◽  
Phenolic Group ◽  
Independent Molecules ◽  
Dianin's Compound

The title compound, C22H22OS [systematic name: 4-(1,3,3-trimethyl-2,3-dihydro-1H-4-thiaphenanthren-1-yl)phenol], crystallizes unsolvated from nitromethane as colourless prisms (m.p. 425–427 K) in the polar monoclinic space groupIawithZ′ = 2 (moleculesAandB). Both independent molecules possess a very similarproximalconformation, this referring to the juxtaposition of the 4-hydroxyphenyl substituent with respect to thesyn-related methyl group. In the crystal, moleculeAis linked to moleculeBby an O—H...O hydrogen bond. In turn, moleculeBexhibits a weak O—H...π interaction with the phenolic group of moleculeArelated bya-glide symmetry. Together, these lead to [100] chains.

Hydrogen bond dynamics in water studied by depolarized Rayleigh scattering

1983 ◽  
Vol 44 (4) ◽  
pp. 525-529 ◽  
Author(s):  
O. Conde ◽  
J. Teixeira
Keyword(s):  
Hydrogen Bond ◽  
Rayleigh Scattering ◽  
Hydrogen Bond Dynamics

A Hydrogen Bond Between Linear Tetrapyrrole and Conserved Aspartate Causes the Far-Red Shifted Absorption of Phytochrome Photoreceptors

2020 ◽  
Author(s):  
Egle Maximowitsch ◽  
Tatiana Domratcheva
Keyword(s):  
Hydrogen Bond ◽  
Light Adaptation ◽  
Positive Charge ◽  
Pyrrole Ring ◽  
Md Simulations ◽  
Spectral Shift ◽  
Specific Domain ◽  
Study Guides ◽  
Rational Engineering ◽  
Tuning Mechanism

Photoswitching of phytochrome photoreceptors between red-absorbing (Pr) and far-red absorbing (Pfr) states triggers light adaptation of plants, bacteria and other organisms. Using quantum chemistry, we elucidate the color-tuning mechanism of phytochromes and identify the origin of the Pfr-state red-shifted spectrum. Spectral variations are explained by resonance interactions of the protonated linear tetrapyrrole chromophore. In particular, hydrogen bonding of pyrrole ring D with the strictly conserved aspartate shifts the positive charge towards ring D thereby inducing the red spectral shift. Our MD simulations demonstrate that formation of the ring D–aspartate hydrogen bond depends on interactions between the chromophore binding domain (CBD) and phytochrome specific domain (PHY). Our study guides rational engineering of fluorescent phytochromes with a far-red shifted spectrum.

Probing the Structural Features and the Micro-heterogeneity of Various Deep Eutectic Solvents and their Water Dilutions by the Photophysical Behaviour of Two Fluorophores

2020 ◽  
Author(s):  
Matteo Tiecco ◽  
Irene Di Guida ◽  
Pier Luigi Gentili ◽  
Raimondo Germani ◽  
Carmela Bonaccorso ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Transient Absorption ◽  
Photophysical Properties ◽  
Deep Eutectic Solvents ◽  
Structural Features ◽  
Solvation Dynamics ◽  
Structured Systems ◽  
Reduced Viscosity ◽  
Bond Network ◽  
Fluorescent Molecules

<div><div><div><p>The structural features of a series of diverse Deep Eutectic Solvents (DESs) have been investigated and characterized by means of two fluorescent probes. The spectral and photophysical properties of the latter are strictly dependent on the experienced environment, so that they can provide insights into the polarity, viscosity, hydrogen-bond network, and micro-heterogeneity of the various DESs.</p><p>In fact, the investigated DESs exhibit a variety of properties with regards to their hydrophilicity, acidity, and hydrogen-bond ability, and these details were deeply probed by the two fluorescent molecules. The effect of the addition of water, which is a key strategy for tuning the properties of these structured systems, was also tested. In particular, the excited state dynamics of the probes, measured by femtosecond-resolved transient absorption, proved instrumental in understanding the changes in the structural properties of the DESs, namely reduced viscosity and enhanced heterogeneity, as the water percentage increases. Differences between the various DESs in terms of both local microheterogeneity and bulk viscosity also emerged from the peculiar multi-exponential solvation dynamics undergone by the excited states of the probes.</p></div></div></div>

Probing the Structural Features and the Micro-heterogeneity of Various Deep Eutectic Solvents and their Water Dilutions by the Photophysical Behaviour of Two Fluorophores

2020 ◽  
Author(s):  
Matteo Tiecco ◽  
Irene Di Guida ◽  
Pier Luigi Gentili ◽  
Raimondo Germani ◽  
Carmela Bonaccorso ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Transient Absorption ◽  
Photophysical Properties ◽  
Deep Eutectic Solvents ◽  
Structural Features ◽  
Solvation Dynamics ◽  
Structured Systems ◽  
Reduced Viscosity ◽  
Bond Network ◽  
Fluorescent Molecules

<div><div><div><p>The structural features of a series of diverse Deep Eutectic Solvents (DESs) have been investigated and characterized by means of two fluorescent probes. The spectral and photophysical properties of the latter are strictly dependent on the experienced environment, so that they can provide insights into the polarity, viscosity, hydrogen-bond network, and micro-heterogeneity of the various DESs.</p><p>In fact, the investigated DESs exhibit a variety of properties with regards to their hydrophilicity, acidity, and hydrogen-bond ability, and these details were deeply probed by the two fluorescent molecules. The effect of the addition of water, which is a key strategy for tuning the properties of these structured systems, was also tested. In particular, the excited state dynamics of the probes, measured by femtosecond-resolved transient absorption, proved instrumental in understanding the changes in the structural properties of the DESs, namely reduced viscosity and enhanced heterogeneity, as the water percentage increases. Differences between the various DESs in terms of both local microheterogeneity and bulk viscosity also emerged from the peculiar multi-exponential solvation dynamics undergone by the excited states of the probes.</p></div></div></div>

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