Key components in chemical transformations are catalysts, i.e., molecules that provide low energy pathways for chemical reactions to proceed. Nature itself is a master of catalysis, where in billions of years of evolution amazing catalytic systems have been established that form the very foundation of life: enzymes. Recently, polymer chemistry has developed synthetic methodologies that open for the first time the enticing prospect of emulating the complex and highly controlled chain structure of enzymes. In particular, single-chain polymer nanoparticles (SCNPs) have emerged as bioinspired ultra-fine soft nano-objects (5-20 nm) with huge potential for catalysis, among other different applications. In this research line, the UPV/EHU group (PSMG) and the UB partner (LCPO) involved aim to generate carbene-metal complexes as dual catalytic and intra-chain cross-linkers as an original way to develop a new generation of innovative catalytic nanoreactors based on single-chain nanoparticles as highly efficient artificial enzymes.

The constant formation and breaking of reversible bonds (non-covalent or dynamically covalent) is a phenomenon present in many systems of interest in soft matter and biophysics. A common characteristic is the supramolecular organization in clusters, or in a percolating network when the energy and concentration of the bonds is high enough. Clusters and networks are dynamic. Due to the finite lifetime of the bonds their specific connectivity is not fixed and is in continuous reorganization. This feature adds additional complexity to the structural and dynamic properties of the system. Poorly understood processes in these systems are the formation and rupture of temporary polymeric structures in low molecular weight liquids, the relaxation of the collective correlations in the mesoscale of physical gels, the effect of the dynamic network on the physical aging of the material, or the microscopic mechanisms behind the so-called topology freezing transition temperature (below which the bonding pattern of the network is unable to relax). The main objective of this research line is to advance beyond the state of the art the fundamentals of the effect of reversible bonds, and the resulting supramolecular organization, on the dynamics and structure of soft matter systems based on low-molecular weight molecules, polymers and biopolymers.