scholarly journals Photochemical Dissipative Structuring of the Fundamental Molecules of Life

Proceedings ◽  
2019 ◽  
Vol 46 (1) ◽  
pp. 20
Author(s):  
Karo Michaelian
Keyword(s):  
Nonequilibrium Thermodynamics ◽  
Irreversible Thermodynamic ◽  
Stationary States ◽  
Long Wavelength ◽  
Common Precursor ◽  
Molecular Concentration ◽  
Wavelength Absorption ◽  
Nonequilibrium Conditions ◽  
Precursor Molecules ◽  
Selection Of

It has been conjectured that the origin of the fundamental molecules of life, their proliferation over the surface of Earth, and their complexation through time, are examples of photochemical dissipative structuring, dissipative proliferation, and dissipative selection, respectively, arising out of the nonequilibrium conditions created on Earth’s surface by the solar photon spectrum. Here I describe the nonequilibrium thermodynamics and the photochemical mechanisms involved in the synthesis and evolution of the fundamental molecules of life from simpler more common precursor molecules under the long wavelength UVC and UVB solar photons prevailing at Earth’s surface during the Archean. Dissipative structuring through photochemical mechanisms leads to carbon based UVC pigments with peaked conical intersections which endow them with a large photon disipative capacity (broad wavelength absorption and rapid radiationless dexcitation). Dissipative proliferation occurs when the photochemical dissipative structuring becomes autocatalytic. Dissipative selection arises when fluctuations lead the system to new stationary states (corresponding to different molecular concentration profiles) of greater dissipative capacity as predicted by the universal evolution criterion of Classical Irreversible Thermodynamic theory established by Onsager, Glansdorff, and Prigogine. An example of the UV photochemical dissipative structuring, proliferation, and selection of the nucleobase adenine from an aqueous solution of HCN under UVC light is given.

scholarly journals The Dissipative Photochemical Origin of Life: UVC Abiogenesis of Adenine

2021 ◽  
Author(s):  
Karo Michaelian
Keyword(s):  
Origin Of Life ◽  
Kinetic Equations ◽  
Reaction Rates ◽  
Photon Flux ◽  
Common Precursor ◽  
Wavelength Absorption ◽  
The Common ◽  
The Origin Of Life ◽  
Precursor Molecules ◽  
Non Equilibrium

I describe the non-equilibrium thermodynamics and the photochemical mechanisms which may have been involved in the dissipative synthesis, proliferation, and evolution of the fundamental molecules at the origin of life from simpler and more common precursor molecules such as HCN, H2O and CO2 under the impressed UVC photon flux of the Archean. The fundamental molecules absorb strongly in this UVC region and exhibit strong coupling between their electronic excited and ground states which endows them with efficient photon disipative capacity (broad wavelength absorption and rapid radiationless dexcitation) suggestive of dissipative structuring. The autocatalytic nature of the synthesized molecules in dissipating the same photochemical potential that directed their synthesis leads to their proliferation. The non-linearity in the photochemical and chemical reaction rates provides numerous stationary states which can be reached by amplification of a molecular concentration fluctuation near a bifurcation, promoting the system into states of generally higher photon disspative efficacy. An example is given of the UV photochemical dissipative structuring, proliferation, and evolution of molecules on route to the nucleobase adenine from the common precursor molecules HCN and H2O occurring within a fatty acid vesicle. The kinetic equations are resolved under different environmental conditions, providing a non-equilibrium thermodynamic analysis of the appearance of an early important molecule for the origin of life.

scholarly journals The Dissipative Photochemical Origin of Life: UVC Abiogenesis of Adenine

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 217
Author(s):  
Karo Michaelian
Keyword(s):  
Origin Of Life ◽  
Kinetic Equations ◽  
Irreversible Thermodynamic ◽  
Photochemical Reactions ◽  
Photon Flux ◽  
Absorption Bands ◽  
Water Solvent ◽  
Wavelength Absorption ◽  
Far From Equilibrium ◽  
Selection Of

The non-equilibrium thermodynamics and the photochemical reaction mechanisms are described which may have been involved in the dissipative structuring, proliferation and complexation of the fundamental molecules of life from simpler and more common precursors under the UVC photon flux prevalent at the Earth’s surface at the origin of life. Dissipative structuring of the fundamental molecules is evidenced by their strong and broad wavelength absorption bands in the UVC and rapid radiationless deexcitation. Proliferation arises from the auto- and cross-catalytic nature of the intermediate products. Inherent non-linearity gives rise to numerous stationary states permitting the system to evolve, on amplification of a fluctuation, towards concentration profiles providing generally greater photon dissipation through a thermodynamic selection of dissipative efficacy. An example is given of photochemical dissipative abiogenesis of adenine from the precursor HCN in water solvent within a fatty acid vesicle floating on a hot ocean surface and driven far from equilibrium by the incident UVC light. The kinetic equations for the photochemical reactions with diffusion are resolved under different environmental conditions and the results analyzed within the framework of non-linear Classical Irreversible Thermodynamic theory.

Positive selection of the long-wavelength opsin gene in South American cichlid fishes

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Thomaz Mansini Carrenho Fabrin ◽  
Luciano Seraphim Gasques ◽  
Rodrigo Junio da Graça ◽  
Sônia Maria Alves Pinto Prioli ◽  
Weferson Júnio da Graça ◽  
...  
Keyword(s):  
Positive Selection ◽  
Opsin Gene ◽  
South American ◽  
Long Wavelength ◽  
Cichlid Fishes ◽  
Selection Of

Photocytotoxicity of Anthracyclines upon Laser Excitation in Their Long-Wavelength Absorption Bands

1991 ◽  
Vol 127 (1) ◽  
pp. 24 ◽  
Author(s):  
Alessandra Andreoni ◽  
Alberto Colasanti ◽  
Vincenzo Malatesta ◽  
Giuseppe Roberti
Keyword(s):  
Laser Excitation ◽  
Absorption Bands ◽  
Long Wavelength ◽  
Wavelength Absorption

scholarly journals Электронное строение и спектрально-флуоресцентные свойства лазерных красителей тиопирило-4-трикарбоцианинов

2021 ◽  
Vol 129 (7) ◽  
pp. 862
Author(s):  
А.А. Ищенко ◽  
И.В. Курдюкова ◽  
М.В. Богданович ◽  
С.Л. Бондарев ◽  
А.А. Романенко ◽  
...  
Keyword(s):  
Radiative Transition ◽  
Polymethine Chain ◽  
Long Wavelength ◽  
Vibronic Interactions ◽  
Wide Range ◽  
Wavelength Absorption ◽  
Fluorescent State ◽  
Long Wavelength Absorption Band ◽  
Angle Of Rotation ◽  
Ab Initio Dft

It was found that the long-wavelength absorption band of the laser dye IR 1061 and its analogue with an unsubstituted polymethine chain is strongly broadened and decreases in intensity in polar solvents, while the fluorescence band remains narrow and practically does not change in a wide range of solvent polarities. Based on the quantum-chemical calculations of these dyes by the ab initio DFT/B3LYP/6-31G (d,p) and TDDFT methods, taking into account the polarity of the medium by the PCM method, it is shown that the reason for this difference is the weakening of solvation in the fluorescent state as compared to the ground state due to the greater equalization of the charge in the first than in the latter. An increase in the alternation of bond orders in the polymethine chain in the fluorescent state was found, which causes an increase of vibronic interactions in the radiative transition as compared to the absorptive one. Spectral effects caused by a change in the angle of rotation of phenyl groups in the thiopyrylium cycle upon excitation have been analyzed.

Erstmaliger Nachweis von π–π Dimerenbildung bei stabilen 1,4-Dialkylchinoxalinium-Radikalkationen. Struktur, Spektroskopie und Magnetismus / First Evidence for π-π-Dimerization of the Stable 1,4-Dialkylquinoxalinium Radical Cations. Structure, Spectroscopy and Magnetism

1993 ◽  
Vol 48 (9) ◽  
pp. 1181-1186 ◽  
Author(s):  
H.-D. Hausen ◽  
Wolfgang Kaim ◽  
Andreas Schulz ◽  
Michael Moscherosch ◽  
Jeanne Jordanov
Keyword(s):  
Solid State ◽  
Magnetic Measurements ◽  
Magnetic Moments ◽  
Cation Radical ◽  
Radical Cations ◽  
Long Wavelength ◽  
Wavelength Absorption ◽  
Molecular Structure Analysis ◽  
Long Wavelength Absorption Band ◽  
Quinoxaline Ring

Crystal and molecular structure analysis of 1,4-diethylquinoxalinium iodide shows a virtually planar quinoxaline ring with 11 conjugated π-electrons. In contrast to the triiodide of the 1,4,6,7-tetramethyl derivative or to the tetraphenylborate salt of 1,4-diethylquinoxalinium cation radical the iodide exhibits π-π-dimerized radical cations in the solid state with synplanar ethyl groups and a rather small intermolecular distance of about 315 pm between the π-planes of the primarily interacting 1,4-diazine rings. Solid state magnetic measurements between 2 and 300 K show considerably diminished magnetic moments due to partial spin-pairing, and UV/VIS spectroscopic measurements in acetonitrile reflect the π—π-interaction in solution through the appearance of a long-wavelength absorption band.

High Temperature, High Pressure Absorption Spectra of Uranyl Chloride Solutions Under Shock Conditions

1983 ◽  
Vol 22 ◽  
Author(s):  
Arnold H. Ewald
Keyword(s):  
Shock Wave ◽  
Absorption Spectra ◽  
Room Temperature ◽  
Nitrate Solution ◽  
Appreciable Effect ◽  
Long Wavelength ◽  
Uranyl Perchlorate ◽  
Wavelength Absorption ◽  
High Temperature High Pressure ◽  
Absorption Measurements

In 1960 David and Ewald [1] developed a technique for photographing the absorption spectra of solutions under shock wave conditions. A photograph of the spectrum of a uranyl nitrate solution exposed to a shock wave of 75 kbar showed the absorption to extend beyond 500 nm, the long wavelength limit for uranyl solutions under ordinary conditions. A.H. Ewald (unpublished, 1963) found that at room temperature pressure up to 6 kbar had no appreciable effect on absorption. Bell and Biggers [2,3] published an analysis of the spectrum of uranyl perchlorate solutions. The longest wavelength absorption band was at 486 nm but Bell [4] later found bands at 508 and 531 nm. The intensity of these very weak bands increased when the solution was heated to 95° C, and they were interpreted as “hot bands” due to absorption from an excited ground state. This paper reports new absorption measurements made on uranyl solutions heated to 250°C at low pressure and offers an interpretation of the effect observed in the shock experiments.

Functional group and substituent effects, both steric and electronic, upon the ultraviolet absorption spectra of some N-alkyl- and N,N-dialkyl-derivatives of some cinnamamides and benzalcyanoacetamides

1969 ◽  
Vol 47 (17) ◽  
pp. 3278-3280 ◽  
Author(s):  
A. D. Delaney ◽  
D. J. Currie ◽  
H. L. Holmes
Keyword(s):  
Hydrogen Atom ◽  
Absorption Spectra ◽  
Functional Group ◽  
Substituent Effects ◽  
Ultraviolet Absorption ◽  
Long Wavelength ◽  
Wavelength Absorption ◽  
Derivatives Of

Conjugative and steric constants for N-substituted carboxyamide groups have been derived which allow the calculation of the long wavelength absorption maxima of N-alkyl- and N,N-dialkyl-derivatives of cinnamamide and benzalcyanoacetamide. Deviations between calculated and observed values indicate that there may be steric interference between bulky N,N-dialkylcarboxyamide groups and the benzylic hydrogen atom.

Elaboration of an unexplored substitution site in synthetic bacteriochlorins

2015 ◽  
Vol 19 (07) ◽  
pp. 887-902 ◽  
Author(s):  
Nuonuo Zhang ◽  
Kanumuri Ramesh Reddy ◽  
Jianbing Jiang ◽  
Masahiko Taniguchi ◽  
Roger D. Sommer ◽  
...  
Keyword(s):  
Bathochromic Shift ◽  
Fluorescence Emission ◽  
Bacterial Photosynthesis ◽  
Alkoxy Group ◽  
The Self ◽  
X Ray ◽  
Long Wavelength ◽  
Substitution Site ◽  
Wavelength Absorption ◽  
Long Wavelength Absorption Band

The ability to introduce substituents at designated sites about the perimeter of synthetic bacteriochlorins – analogs of bacteriochlorophylls of bacterial photosynthesis – remains a subject of ongoing study. Here, the self-condensation of a dihydrodipyrrin-dioxolane affords a 5-[2-(trimethylsiloxy)ethoxy]bacteriochlorin. Like a 5-methoxybacteriochlorin, the latter undergoes regioselective bromination at the 15-position, directed by the distal 5-alkoxy group. On the other hand, attempted bromination of a bacteriochlorin bearing a 5-(2-hydroxyethoxy) group resulted in intramolecular ether formation with the adjacent β-pyrroline position to give an annulated dioxepine ring (confirmed by single-crystal X-ray structural analysis). The hydroxyethoxy group at the 5-position can be derivatized by acylation. In addition, the installation of auxochromes (methoxycarbonyl, phenylethynyl) at the β-pyrrole rings causes a substantial bathochromic shift of the long-wavelength absorption band (812 nm) and companion fluorescence emission band (821 nm). Taken together, the modification of the 5-substituent complements existing methods for installing a single substituent on the bacteriochlorin macrocycle.

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