Non-classical effects in proton or hydrogen transfer

2016 ◽  
Vol 88 (10-11) ◽  
pp. 1063-1071 ◽  
Author(s):  
Jacek Waluk
Keyword(s):  
Hydrogen Transfer ◽  
Organic Molecules ◽  
Vibrational Excitation ◽  
Single Molecules ◽  
Electronic States ◽  
Condensed Phases ◽  
Vibrational Modes ◽  
Transfer Path ◽  
Multidimensional Process

AbstractResults of thorough investigations of tautomerism in the ground and excited electronic states performed for various organic molecules under different regimes: condensed phases, isolated and single molecules, with a special emphasis on porphycene, a porphyrin isomer, demonstrate that, in order to precisely describe the proton/hydrogen transfer path, one has to explicitly consider tunneling. Tautomerization is a multidimensional process, controlled by excitation of specific vibrational modes. Vibrational excitation can both enhance or hinder the reaction. The role of specific vibrational modes can now be assessed, even at the level of single molecules.

scholarly journals Critical role of intermediate electronic states for spin-flip processes in charge-transfer-type organic molecules with multiple donors and acceptors

2019 ◽  
Vol 18 (10) ◽  
pp. 1084-1090 ◽  
Author(s):  
Hiroki Noda ◽  
Xian-Kai Chen ◽  
Hajime Nakanotani ◽  
Takuya Hosokai ◽  
Momoka Miyajima ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Organic Molecules ◽  
Critical Role ◽  
Electronic States ◽  
Spin Flip ◽  
Multiple Donors

Evidence for Dominant Role of Tunneling in Condensed Phases and at High Temperatures: Double Hydrogen Transfer in Porphycenes

2016 ◽  
Vol 7 (2) ◽  
pp. 283-288 ◽  
Author(s):  
Piotr Ciąćka ◽  
Piotr Fita ◽  
Arkadiusz Listkowski ◽  
Czesław Radzewicz ◽  
Jacek Waluk
Keyword(s):  
High Temperatures ◽  
Hydrogen Transfer ◽  
Dominant Role ◽  
Condensed Phases ◽  
Double Hydrogen

The Role of Interface Vibrational Modes in Thermal Boundary Resistance

2021 ◽  
Author(s):  
Christopher M. Stanley ◽  
Benjamin K. Rader ◽  
Braxton H. D. Laster ◽  
Mahsa Servati ◽  
Stefan K. Estreicher
Keyword(s):  
Boundary Resistance ◽  
Thermal Boundary Resistance ◽  
Vibrational Modes

scholarly journals Revealing the role of excited state proton transfer (ESPT) in excited state hydrogen transfer (ESHT): systematic study in phenol–(NH3)n clusters

2021 ◽  
Author(s):  
Christophe Jouvet ◽  
Mitsuhiko Miyazaki ◽  
Masaaki Fujii
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Systematic Study ◽  
General Model ◽  
Hydrogen Transfer ◽  
Excited State Proton Transfer

A general model of excited state hydrogen transfer (ESHT) which unifies ESHT and the excited state proton transfer (ESPT) is presented from experimental and theoretical works on phenol–(NH3)n. The hidden role of ESPT is revealed.

scholarly journals Did Cyclic Metaphosphates Have a Role in the Origin of Life?

2021 ◽  
Author(s):  
Thomas Glonek
Keyword(s):  
Organic Molecules ◽  
Water Soluble ◽  
Holliday Junction ◽  
Additional Energy ◽  
Condensed Phosphate ◽  
Geological Processes ◽  
The Origin Of Life ◽  
Complex Forms ◽  
Self Replication

AbstractHow life began still eludes science life, the initial progenote in the context presented herein, being a chemical aggregate of primordial inorganic and organic molecules capable of self-replication and evolution into ever increasingly complex forms and functions.Presented is a hypothesis that a mineral scaffold generated by geological processes and containing polymerized phosphate units was present in primordial seas that provided the initiating factor responsible for the sequestration and organization of primordial life’s constituents. Unlike previous hypotheses proposing phosphates as the essential initiating factor, the key phosphate described here is not a polynucleotide or just any condensed phosphate but a large (in the range of at least 1 kilo-phosphate subunits), water soluble, cyclic metaphosphate, which is a closed loop chain of polymerized inorganic phosphate residues containing only phosphate middle groups. The chain forms an intrinsic 4-phosphate helix analogous to its structure in Na Kurrol’s salt, and as with DNA, very large metaphosphates may fold into hairpin structures. Using a Holliday-junction-like scrambling mechanism, also analogous to DNA, rings may be manipulated (increased, decreased, exchanged) easily with little to no need for additional energy, the reaction being essentially an isomerization.A literature review is presented describing findings that support the above hypothesis. Reviewed is condensed phosphate inorganic chemistry including its geological origins, biological occurrence, enzymes and their genetics through eukaryotes, polyphosphate functions, circular polynucleotides and the role of the Holliday junction, previous biogenesis hypotheses, and an Eoarchean Era timeline.

The long and winding road to new porphycenes

2012 ◽  
Vol 16 (05n06) ◽  
pp. 589-602 ◽  
Author(s):  
Igor Czerski ◽  
Arkadiusz Listkowski ◽  
Jan Nawrocki ◽  
Natalia Urbańska ◽  
Hubert Piwoński ◽  
...  
Keyword(s):  
Fluorescence Polarization ◽  
Hydrogen Transfer ◽  
Single Molecules ◽  
Tert Butyl ◽  
Tautomeric Forms ◽  
By Products ◽  
Double Hydrogen

We describe attempts — not always successful — made over the years to improve the efficiency of porphycene synthesis and to produce novel compounds, custom-designed for specific purposes. New porphycenes are reported, some of them obtained rather unexpectedly as by-products of the planned reactions. Structure and energy computations of possible tautomeric forms in porphycenes substituted by one, two, three, and four tert-butyl groups lead to predictions regarding the kinetics and mechanisms of intramolecular double hydrogen transfer. The occurrence of tautomerization in single molecules of tert-butylsubstituted porphycenes is demonstrated by using fluorescence polarization techniques.

The role of the excited electronic states in the C++H2O reaction

2008 ◽  
Vol 128 (14) ◽  
pp. 144310 ◽  
Author(s):  
Jesús R. Flores ◽  
Adán B. González
Keyword(s):  
Electronic States ◽  
Excited Electronic States

Formation of Oriented Nanostructures from Single Molecules of Conjugated Polymers in Microdroplets of Solution:  The Role of Solvent

2004 ◽  
Vol 37 (16) ◽  
pp. 6132-6140 ◽  
Author(s):  
Pradeep Kumar ◽  
Adosh Mehta ◽  
Shannon M. Mahurin ◽  
Sheng Dai ◽  
Mark D. Dadmun ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Single Molecules ◽  
Role Of Solvent
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