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Venturini A, Vreven T, Bernardi F, Olivucci M, Robb MA. Mechanism of Photodegradation of Polysilanes: A Relaxed Cross Section of the Conical Intersection Hyperline in 2-MethylTrisilane. Organometallics 2002. [DOI: 10.1021/om00010a069] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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177
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Reguero M, Bernardi F, Jones H, Olivucci M, Ragazos IN, Robb MA. A concerted nonadiabatic reaction path for the singlet di-.pi.-methane rearrangement. J Am Chem Soc 2002. [DOI: 10.1021/ja00058a083] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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178
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Bearpark M, Bernardi F, Olivucci M, Robb MA. Factors controlling the synchronous versus asynchronous mechanism of the Cope rearrangement. J Am Chem Soc 2002. [DOI: 10.1021/ja00161a012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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179
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Palmer IJ, Olivucci M, Bernardi F, Robb MA. An MC-SCF study of the thermal and photochemical cycloaddition of Dewar benzene. J Org Chem 2002. [DOI: 10.1021/jo00045a017] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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180
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Bernardi F, Olivucci M, Robb MA. Predicting forbidden and allowed cycloaddition reactions: potential surface topology and its rationalization. Acc Chem Res 2002. [DOI: 10.1021/ar00180a002] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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181
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Bernardi F, De S, Olivucci M, Robb MA. The mechanism of ground-state-forbidden photochemical pericyclic reactions: evidence for real conical intersections. J Am Chem Soc 2002. [DOI: 10.1021/ja00161a013] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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182
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De Vico L, Page CS, Garavelli M, Bernardi F, Basosi R, Olivucci M. Reaction path analysis of the "tunable" photoisomerization selectivity of free and locked retinal chromophores. J Am Chem Soc 2002; 124:4124-34. [PMID: 11942852 DOI: 10.1021/ja017502c] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Multiconfigurational second-order perturbation theory computations and reaction path mapping for the retinal protonated Schiff base models all-trans-nona-2,4,6,8-tetraeniminium and 2-cis-nona-2,4,6,8-tetraeniminium cation demonstrate that, in isolated conditions, retinal chromophores exhibit at least three competing excited-state double bond isomerization paths. These paths are associated with the photoisomerization of the double bonds in positions 9, 11, and 13, respectively, and are controlled by barriers that favor the position 11. The computations provide a basis for the understanding of the observed excited-state lifetime in both naturally occurring and synthetic chromophores in solution and, tentatively, in the protein environment. In particular, we provide a rationalization of the excited-state lifetimes observed for a group of locked retinal chromophores which suggests that photoisomerization in bacteriorhodopsin is the result of simultaneous specific "catalysis" (all-trans --> 13-cis path) accompanied by specific "inhibition" (all-trans --> 11-cis path). The nature of the S(1) --> S(0) decay channel associated with the three paths has also been investigated at the CASSCF level of theory. It is shown that the energy surfaces in the vicinity of the conical intersection for the photoisomerization about the central double bond of retinal (position 11) and the two corresponding lateral double bonds (positions 9 and 13) are structurally different.
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183
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Garavelli M, Bernardi F, Olivucci M, Bearpark MJ, Klein S, Robb MA. Product Distribution in the Photolysis of s-cis Butadiene: A Dynamics Simulation. J Phys Chem A 2001. [DOI: 10.1021/jp012058l] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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184
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Sinicropi A, Pogni R, Basosi R, Robb MA, Gramlich G, Nau WM, Olivucci M. Fluoreszenzlöschung über stufenweisen Wasserstoff-, Elektronen- und Protonentransfer in der Nähe einer konischen Durchdringung. Angew Chem Int Ed Engl 2001. [DOI: 10.1002/1521-3757(20011119)113:22<4313::aid-ange4313>3.0.co;2-l] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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185
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Sinicropi A, Pogni R, Basosi R, Robb MA, Gramlich G, Nau WM, Olivucci M. Fluorescence Quenching by Sequential Hydrogen, Electron, and Proton Transfer in the Proximity of a Conical Intersection. Angew Chem Int Ed Engl 2001; 40:4185-4189. [DOI: 10.1002/1521-3773(20011119)40:22<4185::aid-anie4185>3.0.co;2-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2001] [Indexed: 11/12/2022]
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186
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Robb MA, Olivucci M. Photochemical processes: potential energy surface topology and rationalization using VB arguments. J Photochem Photobiol A Chem 2001. [DOI: 10.1016/s1010-6030(01)00453-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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187
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Garavelli M, Bernardi F, Moliner V, Olivucci M. Intrinsically Competitive Photoinduced Polycyclization and Double-Bond Shift through a Boatlike Conical Intersection This work was supported by the Università di Siena (P.A.R. 99/00), the Università di Bologna (MURST ex-60 %), NATO (CRG 950748), and HFSP (RG 0229/2000-M). Angew Chem Int Ed Engl 2001; 40:1466-1468. [PMID: 11317304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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188
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Garavelli M, Bernardi F, Moliner V, Olivucci M. Intrinsically Competitive Photoinduced Polycyclization and Double-Bond Shift through a Boatlike Conical Intersection. Angew Chem Int Ed Engl 2001. [DOI: 10.1002/1521-3757(20010417)113:8<1514::aid-ange1514>3.0.co;2-t] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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189
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Garavelli M, Bernardi F, Moliner V, Olivucci M. Intrinsically Competitive Photoinduced Polycyclization and Double-Bond Shift through a Boatlike Conical Intersection. Angew Chem Int Ed Engl 2001; 40:1466-1468. [DOI: 10.1002/1521-3773(20010417)40:8<1466::aid-anie1466>3.0.co;2-r] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2000] [Indexed: 11/09/2022]
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190
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Garavelli M, Page CS, Celani P, Olivucci M, Schmid WE, Trushin SA, Fuss W. Reaction Path of a sub-200 fs Photochemical Electrocyclic Reaction. J Phys Chem A 2001. [DOI: 10.1021/jp010359p] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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191
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Blancafort L, Jolibois F, Olivucci M, Robb MA. Potential energy surface crossings and the mechanistic spectrum for intramolecular electron transfer in organic radical cations. J Am Chem Soc 2001; 123:722-32. [PMID: 11456586 DOI: 10.1021/ja003359w] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The structure of the potential energy surface for the intramolecular electron transfer (IET) of four different model radical cations has been determined by using reaction path mapping and conical intersection optimization at the ab initio CASSCF level of theory. We show that, remarkably, the calculated paths reside in regions of the ground-state energy surface whose structure can be understood in terms of the position and properties of a surface crossing between the ground and the first excited state of the reactant. Thus, in the norbornadiene radical cation and in an analogue compound formed by two cyclopentene units linked by a norbornyl bridge, IET proceeds along direct-overlap and super-exchange concerted paths, respectively, that are located far from a sloped conical intersection point and in a region where the excited-state and ground-state surfaces are well separated. A second potential energy surface structure has been documented for 1,2-diamino ethane radical cation and features two parallel concerted (direct) and stepwise (chemical) paths. In this case a peaked conical intersection is located between the two paths. Finally, a third type of energy surface is documented for the bismethyleneadamantane radical cation and occurs when there is, effectively, a seam of intersection points (not a conical intersection) which separates the reactant and product regions. Since the reaction path cannot avoid the intersection, IET can only occur nonadiabatically. These IET paths indicate that quite different IET mechanisms may operate in radical cations, revealing an unexpectedly enriched and flexible mechanistic spectrum. We show that the origin of each path can be analyzed and understood in terms of the one-dimensional Marcus-Hush model.
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192
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Sinicropi A, Pischel U, Basosi R, Nau WM, Olivucci M. Conical Intersections in Charge-Transfer Induced Quenching This work was supported by the Swiss National Science Foundation (Projects 52489.98, 54108.98, and 58000.99), the Fonds der Chemischen Industrie, the Università di Siena (Progetto di Ateneo A.A. 99/00), and NATO (CRG 950748). Angew Chem Int Ed Engl 2000; 39:4582-4586. [PMID: 11169677 DOI: 10.1002/1521-3773(20001215)39:24<4582::aid-anie4582>3.0.co;2-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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193
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Sinicropi A, Pischel U, Basosi R, Nau WM, Olivucci M. Konische Durchdringungen in Charge-Transfer-induzierten Photoreaktionen. Angew Chem Int Ed Engl 2000. [DOI: 10.1002/1521-3757(20001215)112:24<4776::aid-ange4776>3.0.co;2-h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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194
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Page CS, Olivucci M, Merchán M. A Theoretical Study of the Low-Lying States of the Anionic and Protonated Ionic Forms of Urocanic Acid. J Phys Chem A 2000. [DOI: 10.1021/jp001667a] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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195
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González-Luque R, Garavelli M, Bernardi F, Merchán M, Robb MA, Olivucci M. Computational evidence in favor of a two-state, two-mode model of the retinal chromophore photoisomerization. Proc Natl Acad Sci U S A 2000; 97:9379-84. [PMID: 10944211 PMCID: PMC16872 DOI: 10.1073/pnas.97.17.9379] [Citation(s) in RCA: 259] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In this paper we use ab initio multiconfigurational second-order perturbation theory to establish the intrinsic photoisomerization path model of retinal chromophores. This is accomplished by computing the ground state (S(0)) and the first two singlet excited-state (S(1), S(2)) energies along the rigorously determined photoisomerization coordinate of the rhodopsin chromophore model 4-cis-gamma-methylnona-2,4,6,8-tetraeniminium cation and the bacteriorhodopsin chromophore model all-trans-hepta-2,4, 6-trieniminium cation in isolated conditions. The computed S(2) and S(1) energy profiles do not show any avoided crossing feature along the S(1) reaction path and maintain an energy gap >20 kcal small middle dotmol(-1). In addition, the analysis of the charge distribution shows that there is no qualitative change in the S(2) and S(1) electronic structure along the path. Thus, the S(1) state maintains a prevalent ionic (hole-pair) character whereas the S(2) state maintains a covalent (dot-dot) character. These results, together with the analysis of the S(1) reaction coordinate, support a two-state, two-mode model of the photoisomerization that constitutes a substantial revision of the previously proposed models.
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196
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Fernández E, Blancafort L, Olivucci M, Robb MA. Intramolecular Electron Transfer: Independent (Ground State) Adiabatic (Chemical) and Nonadiabatic Reaction Pathways in Bis(hydrazine) Radical Cations. J Am Chem Soc 2000. [DOI: 10.1021/ja000013c] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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197
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Jolibois F, Bearpark MJ, Klein S, Olivucci M, Robb MA. A Three-State Nonadiabatic Model for Intramolecular Electronic Energy Transfer (IEET) in 9-Anthryl-1‘-naphthylalkanes Studied by Molecular Mechanics/Valence Bond Dynamics. J Am Chem Soc 2000. [DOI: 10.1021/ja992717w] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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198
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Garavelli M, Smith BR, Bearpark MJ, Bernardi F, Olivucci M, Robb MA. Relaxation Paths and Dynamics of Photoexcited Polyene Chains: Evidence for Creation and Annihilation of Neutral Soliton Pairs. J Am Chem Soc 2000. [DOI: 10.1021/ja000385l] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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199
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Sanchez-Galvez A, Hunt P, Robb MA, Olivucci M, Vreven T, Schlegel HB. Ultrafast Radiationless Deactivation of Organic Dyes: Evidence for a Two-State Two-Mode Pathway in Polymethine Cyanines. J Am Chem Soc 2000. [DOI: 10.1021/ja993985x] [Citation(s) in RCA: 161] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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200
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Page CS, Merchán M, Serrano-Andrés L, Olivucci M. A Theoretical Study of the Low-Lying Excited States of trans- and cis-Urocanic Acid. J Phys Chem A 1999. [DOI: 10.1021/jp991657d] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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