This book introduces some methods for the determination of the three-dimensional geometry of molecules in solution and the occurrence of dynamical processes (interaction with the solvent, rearrangements in the molecular geometry, interactions with other molecules) in several ytterbium complexes. An especial attention has been deserved to the study of some important catalysts that were recently developed in the scientific research. The determination of molecular geometry and dynamics in solution, even if it is generally a hard task, is often a crucial step to understand and rationalize the catalytic mechanism, as well to design new catalysts. The proposed methods are applied here to several systems, even chiral, and are founded on a detailed analysis of the paramagnetic and optical properties of the ytterbium ion, and combining several instrumental techniques (mainly Nuclear Magnetic Resonance and Circular Dichroism).