scholarly journals Four resonance structures elucidate double-bond isomerisation of a biological chromophore

2020 ◽  
Vol 22 (16) ◽  
pp. 8535-8544 ◽  
Author(s):  
Evgeniy V. Gromov ◽  
Tatiana Domratcheva
Keyword(s):  
Hydrogen Bonding ◽  
Electronic Structure ◽  
Double Bond ◽  
Excited States ◽  
Resonance Structures ◽  
Hydrogen Bonding Interactions ◽  
Photochemical Properties

Four resonance structures determining the electronic structure of the chromophore’s ground and first excited states. Changing the relative energies of the structures by hydrogen-bonding interactions tunes all chromophore’s photochemical properties.

scholarly journals Four Resonance Structures Elucidate Double-Bond Isomerisation of a Biological Chromophore

2020 ◽  
Author(s):  
Evgeniy Gromov ◽  
Tatiana Domratcheva
Keyword(s):  
Electronic Structure ◽  
Double Bond ◽  
Protein Interactions ◽  
Fluorescent Proteins ◽  
Closed Shell ◽  
Photoactive Yellow Protein ◽  
Resonance Structures ◽  
Highly Sensitive ◽  
Photochemical Properties ◽  
High Level

Photoinduced double-bond isomerisation of the chromophore of photoactive yellow protein (PYP) is highly sensitive to chromophore-protein interactions. On the basis of high-level ab initio calculations, using the XMCQDPT2 method, we scrutinise the effect of the chromophore-protein hydrogen bonds on the photophysical and photochemical properties of the chromophore. We identify four resonance structures – two closed-shell and two biradicaloid – that elucidate the electronic structure of the ground and first excited states involved in the isomerisation process. Changing the relative energies of the resonance structures by hydrogen-bonding interactions tunes all photochemical properties of the chromophore in an interdependent manner. Our study sheds new light on the role of the chromophore electronic structure in tuning in photosensors and fluorescent proteins.

scholarly journals Four Resonance Structures Elucidate Double-Bond Isomerisation of a Biological Chromophore

2020 ◽  
Author(s):  
Evgeniy Gromov ◽  
Tatiana Domratcheva
Keyword(s):  
Electronic Structure ◽  
Double Bond ◽  
Protein Interactions ◽  
Fluorescent Proteins ◽  
Closed Shell ◽  
Photoactive Yellow Protein ◽  
Resonance Structures ◽  
Highly Sensitive ◽  
Photochemical Properties ◽  
High Level

Photoinduced double-bond isomerisation of the chromophore of photoactive yellow protein (PYP) is highly sensitive to chromophore-protein interactions. On the basis of high-level ab initio calculations, using the XMCQDPT2 method, we scrutinise the effect of the chromophore-protein hydrogen bonds on the photophysical and photochemical properties of the chromophore. We identify four resonance structures – two closed-shell and two biradicaloid – that elucidate the electronic structure of the ground and first excited states involved in the isomerisation process. Changing the relative energies of the resonance structures by hydrogen-bonding interactions tunes all photochemical properties of the chromophore in an interdependent manner. Our study sheds new light on the role of the chromophore electronic structure in tuning in photosensors and fluorescent proteins.

scholarly journals Crystal structure and Hirshfeld surface analysis of (E)-4-amino-N′-[1-(4-methylphenyl)ethylidene]benzohydrazide

2017 ◽  
Vol 73 (7) ◽  
pp. 1029-1032 ◽  
Author(s):  
Palaniyappan Sivajeyanthi ◽  
Muthaiah Jeevaraj ◽  
Bellarmin Edison ◽  
Kasthuri Balasubramani
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Schiff Base ◽  
Double Bond ◽  
Surface Analysis ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Hydrogen Bonding Interactions ◽  
High Propensity ◽  
Benzene Rings

The structure of the title Schiff base, C16H17N3O, displays atransconfiguration with respect to the C=N double bond, with a dihedral angle of 14.98 (9)° between the benzene rings. In the crystal, molecules are linked by N—H...O and C—H...O hydrogen-bonding interactions, giving sheets extending across the (001) plane. Hirshfeld surface analysis gave fingerprint plots showing enrichment ratios for H...H, O...H, N...H and C...H contacts compared to C...C, N...N and C...N contacts, indicating a high propensity for H...H interactions to form in the crystal.

The Role of Hydrogen-Bonding Interactions in the Ultrafast Relaxation Dynamics of the Excited States of 3- and 4-Aminofluoren-9-ones

ChemPhysChem ◽  
2009 ◽  
Vol 10 (17) ◽  
pp. 2995-3012 ◽  
Author(s):  
Jahur A. Mondal ◽  
Vaishali Samant ◽  
Mahendra Varne ◽  
Ajay K. Singh ◽  
Tapan K. Ghanty ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Excited States ◽  
Relaxation Dynamics ◽  
Ultrafast Relaxation ◽  
Hydrogen Bonding Interactions

Synthesis and Photochemical Properties of Re(I) Tricarbonyl Complexes Bound to Thione and Thiazole-2-ylidene Ligands

2020 ◽  
Author(s):  
Matthew Stout ◽  
Brian Skelton ◽  
Alexandre N. Sobolev ◽  
Paolo Raiteri ◽  
Massimiliano Massi ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Ligand Exchange ◽  
Ligand Substitution ◽  
Bidentate Ligand ◽  
The Other ◽  
Ligand Exchange Reaction ◽  
Multiple Products ◽  
Ligand Charge Transfer ◽  
Photochemical Properties

<p>Three Re(I) tricarbonyl complexes, with general formulation Re(N^L)(CO)<sub>3</sub>X (where N^L is a bidentate ligand containing a pyridine functionalized in the position 2 with a thione or a thiazol-2-ylidene group and X is either chloro or bromo) were synthesized and their reactivity explored in terms of solvent-dependent ligand substitution, both in the ground and excited states. When dissolved in acetonitrile, the complexes bound to the thione ligand underwent ligand exchange with the solvent resulting in the formation of Re(NCMe)<sub>2</sub>(CO)<sub>3</sub>X. The exchange was found to be reversible, and the starting complex was reformed upon removal of the solvent. On the other hand, the complexes appeared inert in dichloromethane or acetone. Conversely, the complex bound to the thiazole-2-ylidene ligand did not display any ligand exchange reaction in the dark, but underwent photoactivated ligand substitution when excited to its lowest metal-to-ligand charge transfer manifold. Photolysis of this complex in acetonitrile generated multiple products, including Re(I) tricarbonyl and dicarbonyl solvato-complexes as well as free thiazole-2-ylidene ligand.</p>

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