The area of catalysis is now at the forefront of the chemical sciences in light of environmental and economic issues. Synthesizing bulk, fine and pharmaceutical compounds using catalysis is now a must in the modern economy. The studies described in the present proposal make use of the full arsenal of techniques available for modern synthetic chemical investigation: fundamental physicochemical studies, experiment-based rational catalyst design and catalytic studies. The exploratory physicochemical experiments to be performed make use of classical solution reaction calorimetry involving air- and moisture sensitive complexes. This area is very poorly investigated worldwide. The PI is a world leader in the area of organometallic thermochemistry, a technique that is proposed for elaboration in Spain. This section of the proposal will permit an increase of knowledge on fundamental catalytic systems, allowing for determination of enthalpy and kinetics of key reaction steps involved in homogeneous catalysis. Much needed thermodynamic information will be generated for palladium, gold, iridium and rhenium systems. The development of a rhenium-based system is proposed for investigation in the area of olefin metathesis. Furthermore, ruthenium-systems enabling alkyne metathesis are targeted for synthesis. The development of such olefin modifying system would greatly benefit Europe as catalytic transformations have huge potential in polymer, pharmaceutical and fine chemical industries. The proposed work is both fundamental and applied high risk and high reward. It is outside the presently investigated areas of research carried out by our group at the ICIQ. The Principal Investigator (PI) has 25 years of experience in fundamental and applied chemical research and 15 years of experience as an independent researcher in homogeneous catalysis and organometallic chemistry.