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Michaelian K. The Pigment World: Life's Origins as Photon-Dissipating Pigments. Life (Basel) 2024; 14:912. [PMID: 39063667 DOI: 10.3390/life14070912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Revised: 07/03/2024] [Accepted: 07/06/2024] [Indexed: 07/28/2024] Open
Abstract
Many of the fundamental molecules of life share extraordinary pigment-like optical properties in the long-wavelength UV-C spectral region. These include strong photon absorption and rapid (sub-pico-second) dissipation of the induced electronic excitation energy into heat through peaked conical intersections. These properties have been attributed to a "natural selection" of molecules resistant to the dangerous UV-C light incident on Earth's surface during the Archean. In contrast, the "thermodynamic dissipation theory for the origin of life" argues that, far from being detrimental, UV-C light was, in fact, the thermodynamic potential driving the dissipative structuring of life at its origin. The optical properties were thus the thermodynamic "design goals" of microscopic dissipative structuring of organic UV-C pigments, today known as the "fundamental molecules of life", from common precursors under this light. This "UV-C Pigment World" evolved towards greater solar photon dissipation through more complex dissipative structuring pathways, eventually producing visible pigments to dissipate less energetic, but higher intensity, visible photons up to wavelengths of the "red edge". The propagation and dispersal of organic pigments, catalyzed by animals, and their coupling with abiotic dissipative processes, such as the water cycle, culminated in the apex photon dissipative structure, today's biosphere.
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Affiliation(s)
- Karo Michaelian
- Department of Nuclear Physics and Application of Radiation, Instituto de Física, Universidad Nacional Autónoma de México, Circuito Interior de la Investigación Científica, Cuidad Universitaria, Cuidad de México CP 04510, Mexico
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2
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Michaelian K. The Non-Equilibrium Thermodynamics of Natural Selection: From Molecules to the Biosphere. ENTROPY (BASEL, SWITZERLAND) 2023; 25:1059. [PMID: 37510006 PMCID: PMC10378079 DOI: 10.3390/e25071059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/04/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023]
Abstract
Evolutionary theory suggests that the origin, persistence, and evolution of biology is driven by the "natural selection" of characteristics improving the differential reproductive success of the organism in the given environment. The theory, however, lacks physical foundation, and, therefore, at best, can only be considered a heuristic narrative, of some utility for assimilating the biological and paleontological data at the level of the organism. On deeper analysis, it becomes apparent that this narrative is plagued with problems and paradoxes. Alternatively, non-equilibrium thermodynamic theory, derived from physical law, provides a physical foundation for describing material interaction with its environment at all scales. Here we describe a "natural thermodynamic selection" of characteristics of structures (or processes), based stochastically on increases in the global rate of dissipation of the prevailing solar spectrum. Different mechanisms of thermodynamic selection are delineated for the different biotic-abiotic levels, from the molecular level at the origin of life, up to the level of the present biosphere with non-linear coupling of biotic and abiotic processes. At the levels of the organism and the biosphere, the non-equilibrium thermodynamic description of evolution resembles, respectively, the Darwinian and Gaia descriptions, although the underlying mechanisms and the objective function of selection are fundamentally very different.
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Affiliation(s)
- Karo Michaelian
- Department of Nuclear Physics and Application of Radiation, Instituto de Física, Universidad Nacional Autónoma de México, Circuito Interior de la Investigación Científica, Ciudad Universitaria, Mexico City C.P. 04510, Mexico
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3
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Boeije Y, Olivucci M. From a one-mode to a multi-mode understanding of conical intersection mediated ultrafast organic photochemical reactions. Chem Soc Rev 2023; 52:2643-2687. [PMID: 36970950 DOI: 10.1039/d2cs00719c] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
This review discusses how ultrafast organic photochemical reactions are controlled by conical intersections, highlighting that decay to the ground-state at multiple points of the intersection space results in their multi-mode character.
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Affiliation(s)
- Yorrick Boeije
- Van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Massimo Olivucci
- Chemistry Department, University of Siena, Via Aldo Moro n. 2, 53100 Siena, Italy
- Chemistry Department, Bowling Green State University, Overman Hall, Bowling Green, Ohio 43403, USA
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4
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Guerra C, Ayarde-Henríquez L, Duque-Noreña M, Cárdenas C, Pérez P, Chamorro E. On the nature of bonding in the photochemical addition of two ethylenes: C-C bond formation in the excited state? Phys Chem Chem Phys 2021; 23:20598-20606. [PMID: 34505860 DOI: 10.1039/d1cp03554a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this work, the 2s + 2s (face-to-face) prototypical example of a photochemical reaction has been re-examined to characterize the evolution of chemical bonding. The analysis of the electron localization function (as an indirect measure of the Pauli principle) along the minimum energy path provides strong evidence supporting that CC bond formation occurs not in the excited state but in the ground electronic state after crossing the rhombohedral S1/S0 conical intersection.
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Affiliation(s)
- Cristian Guerra
- Universidad Andres Bello, Facultad de Ciencias Exactas, Departamento de Ciencias Químicas, Avenida República 275, 8370146, Santiago, Chile.
| | - Leandro Ayarde-Henríquez
- Universidad Andres Bello, Facultad de Ciencias Exactas, Departamento de Ciencias Químicas, Avenida República 275, 8370146, Santiago, Chile.
| | - Mario Duque-Noreña
- Universidad Andres Bello, Facultad de Ciencias Exactas, Departamento de Ciencias Químicas, Avenida República 275, 8370146, Santiago, Chile.
| | - Carlos Cárdenas
- Universidad de Chile, Facultad de Ciencias, Departamento de Física, Avenida Las Palmeras 3425, Santiago, Chile. .,Centro para el Desarrollo de la Nanociencia y la Nanotecnología (CEDENNA), 9170124 Santiago, Chile
| | - Patricia Pérez
- Universidad Andres Bello, Facultad de Ciencias Exactas, Departamento de Ciencias Químicas, Avenida República 275, 8370146, Santiago, Chile.
| | - Eduardo Chamorro
- Universidad Andres Bello, Facultad de Ciencias Exactas, Departamento de Ciencias Químicas, Avenida República 275, 8370146, Santiago, Chile.
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5
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Farag MH, Mandal A, Huo P. Polariton induced conical intersection and berry phase. Phys Chem Chem Phys 2021; 23:16868-16879. [PMID: 34328152 DOI: 10.1039/d1cp00943e] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We investigate the Polariton induced conical intersection (PICI) created from coupling a diatomic molecule with the quantized photon mode inside an optical cavity, and the corresponding Berry Phase effects. We use the rigorous Pauli-Fierz Hamiltonian to describe the quantum light-matter interactions between a LiF molecule and the cavity, and use the exact quantum propagation to investigate the polariton quantum dynamics. The molecular rotations relative to the cavity polarization direction play a role as the tuning mode of the PICI, resulting in an effective CI even within a diatomic molecule. To clearly demonstrate the dynamical effects of the Berry phase, we construct two additional models that have the same Born-Oppenheimer surface, but the effects of the geometric phase are removed. We find that when the initial wavefunction is placed in the lower polaritonic surface, the Berry phase causes a π phase-shift in the wavefunction after the encirclement around the CI, indicated from the nuclear probability distribution. On the other hand, when the initial wavefunction is placed in the upper polaritonic surface, the geometric phase significantly influences the couplings between polaritonic states and therefore, the population dynamics between them. These BP effects are further demonstrated through the photo-fragment angular distribution. PICI created from the quantized radiation field has the promise to open up new possibilities to modulate photochemical reactivities.
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Affiliation(s)
- Marwa H Farag
- Department of Chemistry, University of Rochester, 120 Trustee Road, Rochester, New York 14627, USA.
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6
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Buyuktemiz M, Kılıç M, Che Y, Zhao J, Dede Y. When Does Fusing Two Rings Not Yield a Larger Ring? The Curious Case of BOPHY. J Org Chem 2021; 86:4547-4556. [PMID: 33656343 DOI: 10.1021/acs.joc.0c02976] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Muhammed Buyuktemiz
- Department of Chemistry, Faculty of Science, Gazi University, Teknikokullar, 06500 Ankara, Turkey
| | - Murat Kılıç
- Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Yuanyuan Che
- School of Chemistry, Xinjiang University, Urumqi 830046, Xinjiang, P. R. China
| | - Jianzhang Zhao
- School of Chemistry, Xinjiang University, Urumqi 830046, Xinjiang, P. R. China
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, E-208 West Campus, 2 Ling Gong Road, Dalian 116024, P. R. China
| | - Yavuz Dede
- Department of Chemistry, Faculty of Science, Gazi University, Teknikokullar, 06500 Ankara, Turkey
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7
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The Dissipative Photochemical Origin of Life: UVC Abiogenesis of Adenine. ENTROPY 2021; 23:e23020217. [PMID: 33579010 PMCID: PMC7916814 DOI: 10.3390/e23020217] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/22/2021] [Accepted: 02/03/2021] [Indexed: 11/21/2022]
Abstract
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.
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8
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Farfan CA, Turner DB. A systematic model study quantifying how conical intersection topography modulates photochemical reactions. Phys Chem Chem Phys 2020; 22:20265-20283. [PMID: 32966428 DOI: 10.1039/d0cp03464a] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Despite their important role in photochemistry and expected presence in most polyatomic molecules, conical intersections have been thoroughly characterized in a comparatively small number of systems. Conical intersections can confer molecular photoreactivity or photostability, often with remarkable efficacy, due to their unique structure: at a conical intersection, the adiabatic potential energy surfaces of two or more electronic states are degenerate, enabling ultrafast decay from an excited state without radiative emission, known as nonadiabatic transfer. Furthermore, the precise conical intersection topography determines fundamental properties of photochemical processes, including excited-state decay rate, efficacy, and molecular products that are formed. However, these relationships have yet to be defined comprehensively. In this article, we use an adaptable computational model to investigate a variety of conical intersection topographies, simulate resulting nonadiabatic dynamics, and calculate key photochemical observables. We varied the vibrational mode frequencies to modify conical intersection topography systematically in four primary classes of conical intersections and quantified the resulting rate, total yield, and product yield of nonadiabatic decay. The results reveal that higher vibrational mode frequencies reduce nonadiabatic transfer, but increase the transfer rate and resulting photoproduct formation. These trends can inform progress toward experimental control of photochemical reactions or tuning of molecules' photochemical properties based on conical intersections and their topography.
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Affiliation(s)
- Camille A Farfan
- Department of Chemistry, New York University, New York, NY 10003, USA
| | - Daniel B Turner
- Department of Chemistry, New York University, New York, NY 10003, USA
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9
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Sen S, Chattopadhyay A. A Computational Study on the Photochemistry of 2,4,4‐Trimethyl‐1‐pyrroline 1‐Oxide and Investigation on the Reaction Paths of Its Photoproduct Oxaziridine. ChemistrySelect 2019. [DOI: 10.1002/slct.201903230] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Sindhuja Sen
- Department of ChemistryBirla Institute of Technology and Science (BITS)Pilani –K.K. Birla Goa Campus Goa 403 726 India
| | - Anjan Chattopadhyay
- Department of ChemistryBirla Institute of Technology and Science (BITS)Pilani –K.K. Birla Goa Campus Goa 403 726 India
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10
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Aldaz C, Kammeraad JA, Zimmerman PM. Discovery of conical intersection mediated photochemistry with growing string methods. Phys Chem Chem Phys 2018; 20:27394-27405. [PMID: 30357173 PMCID: PMC6532651 DOI: 10.1039/c8cp04703k] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Conical intersections (CIs) are important features of photochemistry that determine yields and selectivity. Traditional CI optimizers require significant human effort and chemical intuition, which typically restricts searching to only a small region of the CI space. Herein, a systematic approach utilizing the growing string method is introduced to locate multiple CIs. Unintuitive MECI are found using driving coordinates that can be generated using a combinatorial search, and subsequent optimization allows reaction pathways, transition states, products, and seam-space pathways to be located. These capabilities are demonstrated by application to two prototypical photoisomerization reactions and the dimerization of butadiene. In total, many reaction pathways were uncovered, including the elusive stilbene hula-twist mechanism, and a previously unidentified product in butadiene dimerization. Overall, these results suggest that growing string methods provide a predictive strategy for exploring photochemistry.
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Affiliation(s)
- Cody Aldaz
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
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11
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Harabuchi Y, Taketsugu T, Maeda S. Combined gradient projection/single component artificial force induced reaction (GP/SC-AFIR) method for an efficient search of minimum energy conical intersection (MECI) geometries. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.02.069] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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12
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Farag MH, Jansen TLC, Knoester J. Probing the Interstate Coupling near a Conical Intersection by Optical Spectroscopy. J Phys Chem Lett 2016; 7:3328-3334. [PMID: 27509384 DOI: 10.1021/acs.jpclett.6b01463] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Conical intersections are points where adiabatic potential energy surfaces cross. The interstate coupling between the potential energy surfaces plays a crucial role in many processes associated with conical intersections. Still no method exists to measure this coupling driving the chemical reactions between the potential energy surfaces involved. In this Letter, using a generic model for photoisomerization, we propose a novel experimental approach to estimate the coupling that mixes the electronic states near a conical intersection. The approach is based on analyzing the vibrational wavepacket of the reactant in the adiabatic ground and excited electronic states. The nuclear wavepacket dynamics are extracted from linear absorption and two-dimensional electronic spectroscopy. Comparing the frequencies of the coupling mode in the adiabatic ground and excited states from models with and without coupling between the potential energy surfaces suggests an experimental tool to determine the interstate coupling.
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Affiliation(s)
- Marwa H Farag
- Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Thomas L C Jansen
- Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Jasper Knoester
- Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
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13
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Abstract
Cycloadditions are among the most efficient chemical processes, combining atom economy, stereospecificity, and the ability to generate molecular complexity in a single step. Aromatic rings would in principle be ideal reaction partners, as they contain, at least from the topological point of view, both olefinic and diene subunits; however, the stability of the conjugated aromatic system would be broken by cycloaddition reactions, which are therefore rarely applied, because kinetics and thermodynamics hinder the process. From that aspect, photochemical activation opens interesting perspectives, as one can selectively provide excess energy to one of the reactants but not to the product, thus preventing thermal back reaction. Indeed, aromatic rings show a rich photochemistry, ranging from isomerizations, substitutions, and additions to cycloadditions. In this review, we will focus on cycloadditions, covering literature from early observations up to the present.
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Affiliation(s)
- Richard Remy
- Department of Chemistry, University of Fribourg , Chemin du Musée 9, CH-1700 Fribourg, Switzerland
| | - Christian G Bochet
- Department of Chemistry, University of Fribourg , Chemin du Musée 9, CH-1700 Fribourg, Switzerland
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Wu D, Ganguly R, Li Y, Hoo SN, Hirao H, Kinjo R. Reversible [4 + 2] cycloaddition reaction of 1,3,2,5-diazadiborinine with ethylene. Chem Sci 2015; 6:7150-7155. [PMID: 29861951 PMCID: PMC5952552 DOI: 10.1039/c5sc03174e] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 09/14/2015] [Indexed: 01/06/2023] Open
Abstract
Under ambient conditions, a [4 + 2] cycloaddition reaction of 1,3,2,5-diazadiborinine 1 with ethylene afforded a bicyclo[2.2.2] derivative 2, which was structurally characterized.
Under ambient conditions, a [4 + 2] cycloaddition reaction of 1,3,2,5-diazadiborinine 1 with ethylene afforded a bicyclo[2.2.2] derivative 2, which was structurally characterized. The cyclization process was found to be reversible, and thus retro-[4 + 2] cycloaddition reproduced 1 quantitatively, concomitant with the release of ethylene. Compound 1 reacted regio-selectively and stereo-selectively with styrene derivatives and norbornene, respectively, and these processes were found to be reversible too. Computational studies determined the reaction pathways which were consistent with the regio-selectivity observed in the reaction of styrene, and the reaction was suggested to be essentially concerted but highly asynchronous.
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Affiliation(s)
- Di Wu
- Division of Chemistry and Biological Chemistry , School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371 , Singapore . ;
| | - Rakesh Ganguly
- NTU-CBC Crystallography Facility , Nanyang Technological University , Singapore 637371 , Singapore
| | - Yongxin Li
- NTU-CBC Crystallography Facility , Nanyang Technological University , Singapore 637371 , Singapore
| | - Sin Ni Hoo
- Division of Chemistry and Biological Chemistry , School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371 , Singapore . ;
| | - Hajime Hirao
- Division of Chemistry and Biological Chemistry , School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371 , Singapore . ;
| | - Rei Kinjo
- Division of Chemistry and Biological Chemistry , School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371 , Singapore . ;
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15
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Mendive-Tapia D, Perrier A, Bearpark MJ, Robb MA, Lasorne B, Jacquemin D. New insights into the by-product fatigue mechanism of the photo-induced ring-opening in diarylethenes. Phys Chem Chem Phys 2015; 16:18463-71. [PMID: 25069429 DOI: 10.1039/c4cp03001j] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photochromic properties of diarylethenes, some of the most studied class of molecular switches, are known to be controlled by non-adiabatic decay at a conical intersection seam. Nevertheless, as their fatigue-reaction mechanism - leading to non-photochromic products - is yet to be understood, we investigate the photo-chemical formation of the so-called by-product isomer using three complementary computational methods (MMVB, CASSCF and CASPT2) on three model systems of increasing complexity. We show that for the ring-opening reaction a transition state on S1(2A) involving bond breaking of the penta-ring leads to a low energy S1(2A)/S0(1A) conical intersection seam, which lies above one of the transition states leading to the by-product isomer on the ground state. Therefore, radiationless decay and subsequent side-product formation can take place explaining the photo-degradation responsible for the by-product generation in diarylethene-type molecules. The effect of dynamic electron correlation and the possible role of inter-system crossing along the penta-ring opening coordinate are discussed as well.
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Affiliation(s)
- David Mendive-Tapia
- Chimie Et Interdisciplinarité, Synthèse, Analyse, Modélisation (CEISAM), UMR CNRS no. 6230, BP 92208, Université de Nantes, 2, Rue de la Houssinière, 44322 Nantes, Cedex 3, France.
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Blancafort L. Photochemistry and photophysics at extended seams of conical intersection. Chemphyschem 2014; 15:3166-81. [PMID: 25157686 DOI: 10.1002/cphc.201402359] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Indexed: 11/07/2022]
Abstract
The role of extended seams of conical intersection in excited-state mechanisms is reviewed. Seams are crossings of the potential energy surface in many dimensions where the decay from the excited to the ground state can occur, and the extended seam is composed of different segments lying along a reaction coordinate. Every segment is associated with a different primary photoproduct, which gives rise to competing pathways. This idea is first illustrated for fulvene and ethylene, and then it is used to explain more complex cases such as the dependence of the isomerisation of retinal chromophore isomers on the protein environment, the dependence of the efficiency of the azobenzene photochemical switch on the wavelength of irradiation and the direction of the isomerisation, and the coexistence of different mechanisms in the photo-induced Wolff rearrangement of diazonaphthoquinone. The role of extended seams in the photophysics of the DNA nucleobases and the relationship between two-state seams and three-state crossings is also discussed. As an outlook, the design of optical control strategies based on the passage of the excited molecule through the seam is considered, and it is shown how the excited-state lifetime of fulvene can be modulated by shaping the energy of the seam.
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Affiliation(s)
- Lluís Blancafort
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, Campus de Montilivi, 17071 Girona (Spain).
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Sala M, Kirkby OM, Guérin S, Fielding HH. New insight into the potential energy landscape and relaxation pathways of photoexcited aniline from CASSCF and XMCQDPT2 electronic structure calculations. Phys Chem Chem Phys 2014; 16:3122-33. [DOI: 10.1039/c3cp54418d] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
New insight into the nonadiabatic relaxation dynamics of aniline following excitation to its first three singlet excited states, 11ππ*, 11π3s/πσ* and 21ππ*.
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Affiliation(s)
- Matthieu Sala
- Laboratoire Interdisciplinaire Carnot de Bourgogne UMR 5209 CNRS
- Université de Bourgogne
- F-21078 Dijon, France
| | - Oliver M. Kirkby
- Department of Chemistry
- University College London
- London WC1H 0AJ, UK
| | - Stéphane Guérin
- Laboratoire Interdisciplinaire Carnot de Bourgogne UMR 5209 CNRS
- Université de Bourgogne
- F-21078 Dijon, France
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18
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Robb MA. In This Molecule There Must Be a Conical Intersection. ADVANCES IN PHYSICAL ORGANIC CHEMISTRY 2014. [DOI: 10.1016/b978-0-12-800256-8.00003-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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