Structure and Spectroscopy of Selected Lanthanide Compounds with Coordination Number from 9 to 6

The lecture deals with a group of lanthanide compounds in which some structural factors influence, in a special way, spectroscopic properties of the systems under investigation. The following systems were chosen: three with polymeric structure, two of the dimer type, one a pseudo-dimer system with coordination number (C.N.) = 7, and an octahedral compound of LnL$\text{}_{6}$ type. The crystal structures of the systems under consideration will be shown, their absorption and excitation spectra will be presented and confronted with X-ray data. Radiative and nonradiative processes will be considered and the role of cooperative interactions analyzed. Some aspects of dynamics in solids will be done, too.