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 s tructural factors influence, in a special way, spectroscopic propertie s of the systems under investigation. The following systems were chose n: three with polymeric structure, two of the dimer type, one a pseudo -dimer system with coordination number (C.N.) = 7, and an octahedral c ompound of LnL(6) type. The crystal structures of tile systems under c onsideration will be shown, their absorption and excitation spectra wi ll be presented and confronted with X-ray data. Radiative and nonradia tive processes will be considered and the role of cooperative interact ions analyzed. Some aspects of dynamics in solids will be done, too.