Important progress has been made in these past years both in the real-time observation of fast photoinduced chemical reactions and in the subject of intense laser control of reaction dynamics. 

These are experiments performed in the CLUR facility (Center for Ultrafast Lasers) in collaboration with Prof. Luis Bañares, from the Complutense University, Madrid. The work methodology is based on the use of tuneable, ultrashort laser pulses, in either pump-probe schemes, or pump-control-probe schemes. Observation is made through detection of charged particles in time-of-flight spectrometers in velocity map imaging configuration, a technique which offers detailed information on available energies in the reaction channels and also on the angular character of the processes under study. 

Regarding the subject of real-time observation of molecular dynamics, we would like to emphasize the work done on the bond breaking dynamics of the carbon-iodine bond in a series of alkyl iodides, with both linear and branched chains. This work revealed the crucial role of the radical structure on the redistribution of energy, and in its turn, its effect on the reaction dynamics.

In recent years we have contributed with high impact publications to the field of laser control of chemical reactions.These describe the possibility of control of observables like quantum yields, lifetimes or kinetic energy distributions in processes of molecular photodissociation. Control is exerted through the dynamic Stark effect, the creation of laser-induced conical intersections and the generation of laser-induced potentials. As target species, we have selected methyl iodide, with well known photodissociation processes, and for this case we have been able to show experimentally, as well as simulate theoretically, how the application of a strong laser field, with tailored properties, is capable of changing the “landscape” where the reaction takes place and thus modify its outcome.

Figure. Depiction of laser control of molecular dynamics, represented as the strong oscillating electric field of the laser acting on the reaction and modifying its outcome. The background is an Abel-inverted velocity map image of the methyl fragment resulting from UV dissociation of methyl iodide, under strong field irradiation with an infrared pulse.  

Some recent publications 

G. Balerdi, J. Woodhouse, A. Zanchet, R. de Nalda, M. L. Senent, A. García Vela and L. Bañares, Femtosecond predissociation dynamics of the methyl radical from the 3pz Rydberg state, Phys. Chem. Chem. Phys. (2015), DOI: 10.1039/c5cp05710h.

I.R. Sola, J. González-Vázquez, R. de Nalda, L. Bañares, Strong field laser control of photochemistry, Phys. Chem. Chem. Phys. 17, 13183-13200 (2015).

Oliver M. Kirkby, Matthieu Sala, Garikoitz Balerdi, Rebeca de Nalda, Luis Bañares, Stephane Guerin, Helen H. Fielding, Comparing the electronic relaxation dynamics of aniline and d7-aniline following excitation at 272–238 nm, Phys. Chem. Chem. Phys. 17, 16270-16276 (2015).

E. Corrales, J. González-Vázquez, G. Balerdi, I.R. Sola, R. de Nalda, L. Bañares, Control of ultrafast molecular photodissociation by laser-field-induced potentials, Nature Chemistry 6, 785 (2014).

E. Corrales, V. Loriot, G. Balerdi, J. González-Vázquez, R. de Nalda, L. Bañares, A.H. Zewail, Structural dynamics effects on the ultrafast chemical bond cleavage of a photodissociation reaction, Phys. Chem. Chem. Phys. 16, 8812 (2014).

G Gitzinger, V. Loriot, L. Bañares, R. de Nalda, Pulse shaping control of CH3I multiphoton ionization at 540 nm, J. Mod. Opt. 61, 864 (2014).