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9 p.: gráf. ; Integral cross sections and thermal rate constants have been calculated for the N 2D +H2 reaction and its isotopic variants N 2D +D2 and the two-channel N 2D +HD by means of quasiclassical trajectory and statistical quantum-mechanical model methods on the latest ab initio potential-energy surface T.-S. Ho et al., J. Chem. Phys. 119, 3063 2003 . The effect of rotational excitation of the diatom on the dynamics of these reactions has been investigated and interesting discrepancies between the classical and statistical model calculations have been found. Whereas a net effect of reagent rotation on reactivity is always observed in the classical calculations, only a very slight effect is observed in the case of the asymmetric N 2D +HD reaction for the statistical quantum-mechanical method. The thermal rate constants calculated on this Potential-Energy Surface using quasiclassical trajectory and statistical model methods are in good agreement with the experimental determinations, although the latter are somewhat larger. A reevaluation of the collinear barrier of the potential surface used in the present study seems timely. Further theoretical and experimental studies are needed for a full understanding of the dynamics of the title reaction. © 2005 American Institute of Physics. ; Financial support through the Ramón y Cajal program from the Spanish Ministry of Education and Science. This work has been funded by the Ministry of Education and Science of Spain under Grant Nos. BQU2002-04627-C02-02, FTN2003-08228-CO3-03, and FIS2004-02461 and CAM 07N/0058/2002 and by the European Union through the RTN Reaction Dynamics HPRN-CT-1999-0007 and Project No. MERGCT-2004-513600. The research was performed within the Unidad Asociada "Química Física Molecular" between the Universidad Complutense and the CSIC. ; Peer reviewed

The correlation between chemical structure and predissociation dynamics has been evaluated for a series of linear and branched alkyl iodides with increasing structural complexity by means of femtosecond time-resolved velocity map imaging experiments following excitation on the second absorption band (B-band) at around 201 nm. The time-resolved images for the iodine fragment are reported and analyzed in order to extract electronic predissociation lifetimes and the temporal evolution of the anisotropy while the experimental results are supported by ab initio calculations of the potential energy curves as a function of the C-I distance. Remarkable similarities are observed for all molecules consistent with a major predissociation of the initially populated bound Rydberg states 6A″ and 7A′ through a crossing with the purely repulsive states 7A″, 8A′ and 8A″ leading to a major R + I*(2P1/2) (R = CH3, C2H5, n-C3H7, n-C4H9, i-C3H7 and t-C4H9) dissociation channel. The reported electronic predissociation lifetimes are found to decrease for an increasing size of the linear radical, reflecting the shifts observed in the position of the crossings in the potential energy curves, and very likely a greater non-adiabatic coupling between the initially populated Rydberg states and the repulsive states leading to dissociation induced by other coordinates associated to key vibrational normal modes. The loss of anisotropy is fully accounted for by the parent molecular rotation during predissociation and the rotational temperature of the parent molecule in the molecular beam is reasonably derived ; S.M.P. acknowledges funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie, grant agreement No 842539. This work has been financed by the Spanish MINECO (grant CTQ2015-65033-P) and Ministerio de Ciencia, Innovación y Universidades (grant PGC2018-096444-B-I00)

11 pags., 4 figs., 2 tabs. ; The correlation between chemical structure and predissociation dynamics has been evaluated for a series of linear and branched alkyl iodides with increasing structural complexity by means of femtosecond time-resolved velocity map imaging experiments following excitation on the second absorption band (B-band) at around 201 nm. The time-resolved images for the iodine fragment are reported and analyzed in order to extract electronic predissociation lifetimes and the temporal evolution of the anisotropy while the experimental results are supported by ab initio calculations of the potential energy curves as a function of the C-I distance. Remarkable similarities are observed for all molecules consistent with a major predissociation of the initially populated bound Rydberg states 6A″ and 7A′ through a crossing with the purely repulsive states 7A″, 8A′ and 8A″ leading to a major R + I*(P) (R = CH, CH, n-CH, n-CH, i-CH and t-CH) dissociation channel. The reported electronic predissociation lifetimes are found to decrease for an increasing size of the linear radical, reflecting the shifts observed in the position of the crossings in the potential energy curves, and very likely a greater non-adiabatic coupling between the initially populated Rydberg states and the repulsive states leading to dissociation induced by other coordinates associated to key vibrational normal modes. The loss of anisotropy is fully accounted for by the parent molecular rotation during predissociation and the rotational temperature of the parent molecule in the molecular beam is reasonably derived. ; M.L.M.S. acknowledges fnancial support through a predoctoral contract from Universidad Complutense de Madrid. S.M.P. acknowledges funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie, grant agreement No 842539. Tis work has been fnanced by the Spanish MINECO (grant CTQ2015-65033-P) and Ministerio de Ciencia, Innovación y Universidades (grant PGC2018-096444-B-I00). Te facilities provided by the Center for Ultrafast Lasers of Universidad Complutense de Madrid are acknowledged.

10 pags., 9 figs., 4 tabs. ; The electronic states and the spin–orbit couplings between them involved in the photodissociation process of the radical molecules CH3X, CH3X → CH3 + X (X = O, S), taking place after the Ã(2A1) ← [X with combining tilde](2E) transition, have been investigated using highly correlated ab initio techniques. A two-dimensional representation of both the potential-energy surfaces (PESs) and the couplings is generated. This description includes the C–X dissociative mode and the CH3 umbrella mode. Spin–orbit effects are found to play a relevant role in the shape of the excited state potential-energy surfaces, particularly in the CH3S case where the spin–orbit couplings are more than twice more intense than in CH3O. The potential surfaces and couplings reported here for the present set of electronic states allow for the first complete description of the above photodissociation process. The different photodissociation mechanisms are analyzed and discussed in light of the results obtained. ; This work was supported by MINECO (Spain) (grants No. CTQ2015-65033-P, FIS2013-40626-P, and FIS2016-76418-P) and EU COST Action CM1401 as well as the European Research Council under the European Union's Seventh Framework Programme (FP/ 2007–2013)/ERC Grant Agreement No. 610256 (NANOCOSMOS). This research was carried out within the Unidad Asociada Quımica Fsica Molecular between the Departamento de Quımica Fısica of Universidad Complutense de Madrid (UCM) and Consejo Superior de Investigaciones Cientıficas (CSIC). AB acknowledges the financial support from the Tunisian Ministry of Higher Education, Scientific Research, and Technology, of the Short Term Scientific Mission (STSM) program of the COST Action CM1401, and of LSAMA at the Universite´ de Tunis El Manar that made possible research visits to the Instituto de Fısica Fundamental (CSIC). The Centro de Supercomputación de Galicia (CESGA, Spain) and CTI (CSIC) are acknowledged for the use of their resources. ; Peer Reviewed

9 pags., 4 figs., 1 tab. -- Open Access funded by Creative Commons Atribution Licence 4.0 ; The photochemistry of the ethyl radical following excitation to the 3p Rydberg state is investigated in a joint experimental and theoretical study. Velocity map images for hydrogen atoms detected from photoexcited isotopologues CH3CH2, CH3CD2 and CD3CH2 at 201 nm, are discussed along with high-level ab initio electronic structure calculations of potential energy curves and non-adiabatic coupling matrix elements (NACME). A novel mechanism governed by a conical intersection allowing prompt site-specific hydrogen-atom elimination is presented and discussed. For this mechanism to occur, an initial rovibrational excitation is allocated to the radical permitting to access this reaction pathway and thus to control the ethyl photochemistry. While hydrogen-atom elimination from cold ethyl radicals occurs through internal conversion into lower electronic states followed by slow statistical dissociation, prompt site-specific Ca elimination into CH3CH + H, occurring through a fast non-adiabatic crossing to a valence bound state followed by dissociation through a conical intersection, is accessed by means of an initial ro-vibrational energy content into the radical. The role of a particularly effective vibrational promoting mode in this prompt photochemical reaction pathway is discussed. ; D. V. C. and S. M. P. contributed equally to the paper. D. V. C. thanks a contract from Spanish MINECO under the FPI predoctoral program. S. M. P. acknowledges nancial support from a postdoctoral contract of the Regional Government of Madrid (Spain) (Grant PEJD-2016/IND-3217). A. B. acknowledges the financial support of the Tunisian Ministry of Higher Education, Scientific Research, and Technology, of the Short Term Scientific Mission (STSM) program of the COST Action CM1401, and of LSAMA at the Universite de Tunis El Manar, that made possible research visits to the Instituto de Fısica Fundamental (CSIC, Spain). This work has been nanced by the Spanish MINECO (Grants No. CTQ2015-65033-P, FIS2016- 76418-P and FIS-2016-77889-R) and EU COST Action CM1401. This research has been carried out within the Unidad Asociada Quımica Fısica Molecular between the Departamento de Quiımica Fisica of Universidad Complutense de Madrid and CSIC. The facilities provided by the Centro de Laseres Ultrarrapidos at Universidad Complutense de Madrid are gratefully acknowledged. The Centro de Supercomputacion de Galicia (CESGA, Spain) and CTI (CSIC) are acknowledged for the use of their resources

The search for efficient plasmonic photothermal therapies using nonharmful pulse laser irradiation at the near-infrared (NIR) is fundamental for biomedical cancer research. Therefore, the development of novel assembled plasmonic gold nanostructures with the aim of reducing the applied laser power density to a minimum through hot-spot-mediated cell photothermolysis is an ongoing challenge. We demonstrate that gold nanorods (Au NRs) functionalized at their tips with a pH-sensitive ligand assemble into oligomers within cell lysosomes through hydrogen-bonding attractive interactions. The unique intracellular features of the plasmonic oligomers allow us to significantly reduce the femtosecond laser power density and Au NR dose while still achieving excellent cell killing rates. The formation of gold tip-to-tip oligomers with longitudinal localized surface plasmon resonance bands at the NIR, obtained from low-aspect-ratio Au NRs close in resonance with 800 nm Ti:sapphire 90 fs laser pulses, was found to be the key parameter for realizing the enhanced plasmonic photothermal therapy. ; This work has been funded by the Spanish MINECO (MAT2014-59678-R and CTQ2012-37404-C02-01) and the Madrid Regional Government (S2013/MIT-2807). A.C.-M. and M.C. and I.L.-M. acknowledge the financial support of the ERC Starting Grants "NANOFORCELLS" (ERC-StG-2011-278860) and "MITOCHON" (ERC-StG-2013-338133). A.G.-M. and I.L.-M. acknowledge receipt of Ramón y Cajal Fellowships from the Spanish MINECO. G.G.-R. acknowledges receipt of the FPI Fellowship from the Spanish MINECO. ; Peer reviewed

8 págs.; 6 figs.; 1 tab. ; The photodissociation dynamics of the methyl radical from the 3s and 3pz Rydberg states have been studied using the velocity map and slice ion imaging in combination with pump–probe nanosecond laser pulses. The reported translational energy and angular distributions of the H(2S) photofragment detected by (2+1) REMPI highlight different dissociation mechanisms for the 3s and 3pz Rydberg states. A narrow peak in the translational energy distribution and an anisotropic angular distribution characterize the fast 3s photodissociation, while for the 3pz state Boltzmann-type translational energy and isotropic angular distributions are found. High level ab initio calculations have been performed in order to elucidate the photodissociation mechanisms from the two Rydberg states and to rationalize the experimental results. The calculated potential energy curves highlight a typical predissociation mechanism for the 3s state, characterized by the coupling between the 3s Rydberg state and a valence repulsive state. On the other hand, the photodissociation on the 3pz state is initiated by a predissociation process due to the coupling between the 3pz Rydberg state and a valence repulsive state and constrained, later on, by two conical intersections that allow the system to relax to lower electronic states. Such a mechanism opens up different reaction pathways leading to CH2 photofragments in different electronic states and inducing a transfer of energy between translational and internal modes. ; S. M. P. acknowledges financial support from Campus de Excelencia Internacional Moncloa and LASING S. A. D. V. C. acknowledges a contract from MINECO under the Fondo de Garantıía Juvenil. A. Z. thanks the support from the European Research Council under the European Union's 7th Framework Program (FP7/2007–2013)/ERC Grant agreement 610256 (NANOCOSMOS). M. G. G. is grateful to Spanish MINECO for a contract through Programa de Técnicos de Apoyo a Infraestructuras. This work has been financed by the Spanish MINECO (grants FIS2011- 29596-C02-01, CTQ2012-37404-C02-01, FIS2013-40626-P and CTQ2015-65033-P) and by COST Actions CM1401 and CM05. This research has been carried out within the Unidad Asociada Química Física Molecular between Departamento de Química Física of Universidad Complutense de Madrid (UCM) and Consejo Superior de Investigaciones Científicas (CSIC). The facilities provided by the Centro de Láseres Ultrarrápidos at UCM are acknowledged. The Centro de Supercomputación de Galicia (CESGA, Spain) and CTI (CSIC) are acknowledged for the use of their resources. ; Peer Reviewed

12 pags., 7 figs., 1 tab. ; The time-resolved photodynamics of the methyl iodide cation (CH3I+) are investigated by means of femtosecond XUV-IR pump-probe spectroscopy. A time-delay-compensated XUV monochromator is employed to isolate a specific harmonic, the 9th harmonic of the fundamental 800 nm (13.95 eV, 88.89 nm), which is used as a pump pulse to prepare the cation in several electronic states. A time-delayed IR probe pulse is used to probe the dissociative dynamics on the first excited state potential energy surface. Photoelectrons and photofragment ions - and I+ - are detected by velocity map imaging. The experimental results are complemented with high level ab initio calculations for the potential energy curves of the electronic states of CH3I+ as well as with full dimension on-the-fly trajectory calculations on the first electronically excited state, considering the presence of the IR pulse. The and I+ pump-probe transients reflect the role of the IR pulse in controlling the photodynamics of CH3I+ in the state, mainly through the coupling to the ground state and to the excited state manifold. Oscillatory features are observed and attributed to a vibrational wave packet prepared in the state. The IR probe pulse induces a coupling between electronic states leading to a slow depletion of fragments after the cation is transferred to the ground states and an enhancement of I+ fragments by absorption of IR photons yielding dissociative photoionization. ; MLMS acknowledges financial support through a predoctoral contract from Universidad Complutense de Madrid (Spain) and FULMATEN-CM project funded by Madrid Regional Government under programme Y2018/NMT-5028. GR thanks the Netherlands Organization for Scientific Research (NWO) for financial support (Rubicon 68-50-1410). This project has received funding (SMP) from the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant agreement No. 842539 (ATTO-CONTROL) and has been financed in part by the Spanish State Research Agency (AEI/10.13039/501100011033), Grants PGC2018-096444-B-I00, PID2019-106125GB-I00 and PID2019-106732GB-I00, and the Madrid Regional Government through the program Proyectos Sin´ergicos de I + D (Grant Y2018/NMT-5028 FULMATEN-CM). FM acknowledges support from the 'Severo Ochoa' Programme for Centres of Excellence in R & D (SEV-2016-0686) and the 'María de Maeztu' Programme for Units of Excellence in R & D (CEX2018-000805-M). All calculations were performed at the Mare Nostrum Supercomputer of the Red Española de Supercomputacion (BSC-RES) and the Centro de Computaci ´ on´ Científica de la Universidad Autonoma de Madrid (CCC-UAM). MV and OK acknowledge the support ´ from the Deutsche Forschungsgeminschaft (KO 4920/1-1). This work was performed in the Max Born Institut (Berlin) in the kHz Laboratory and received financial support from LaserLab Europe through the MBI002239 project.