There is a general interest in the possibility of tuning the reaction mechanisms via careful systematic modifications, not only of the steric and electronic environment of the reacting species, but also of the reaction medium and conditions. Although this type of scanning approach has been thoroughly utilised in preparative chemical processes, historically its use in time-resolved chemistry has not been implemented at the same comprehensive level.
In addition to the per se academic interest of these studies, it is obvious than a better knowledge of the mechanisms operating in a reaction has to lead to the general optimization of the processes. This is, selectivity, economy, temperature and pressure conditions, and the presence of any possible catalysing species.
The group’s general research project is based on increasing the kinetico-mechanistic information available on already described reactions, as well as on some new processes specifically designed for this purpose. This research is carried out on processes occurring on Werner type classical complexes, organometallic compounds, and supramolecular coordination assemblies; furthermore, important contributions to the knowledge of the reactivity of the ligands involved are also common.
To accomplish the group’s goal the effect of the introduction of very systematic modifications on the electronic and steric properties of the reactants is analysed. Moreover, the use of a wide range of solvents with very different and varying characteristics represents the final approach to the studies.
To carry out the kinetico-mechanistic studies, the research group has its own equipment that includes stopped-flow instruments, standard and diode-array spectrophotometers, and a pressurizing system for liquids up to 2500 atmospheres for the measurement of activation volumes, both at conventional and stopped-flow time-scales. The group has also automatic titration systems, which allow a complete study of the distributions of the different active species in the reaction medium; a UV-Vis external probe is used for this purpose. All these instruments are assisted by global analysis software that allows the chemometric interpretation of the raw data and the detection of possible reaction intermediates.
Finally, it is important to highlight that the “Mecanismes de Reacció en Química Inorgànica” research group of the Universitat de Barcelona is one of the few internationally active groups in kinetico-mechanistic studies, which provides a significant added value to its activity.
