Our investigations into various sets of lanthanide compounds indicate that increasingstrain on the crystal lattice, induced by reduced ionic radii, can be alleviated by a reorganization of the crystal structure. Comparing purely inorganic lanthanide complexes and lanthanide compounds with organic components implies that the rigidity of the ligand systems has a significant impact on the crystal lattices' abilities to absorb tensions caused by decreasing ionic radii. It seems that compounds incorporating small, highly rigid, polyatomic anions, such as lanthanide hydroxysulfates, more likely reorganize their crystal structure with reduced space for coordination. Compounds incorporating monoatomic anions, such as lanthanide bis-hydroxychlorides, or extended organic systems with higher degrees of flexibility, e.g., lanthanide terephthalates, rather absorb increasing strain without significant changes in the crystal structure. Most recently we have synthesized an extended series of lanthanide 2-niroterephthalates, Ln2(TPNO2)3(H2O)2�2H2O (Ln = Pr - Lu, except Pm). All of these complexes are isostructural and crystallize in the monoclinic crystal system with space group C2/c, and the coordination number 8. The more flexible 2-nitroterephthalate entities seem to allow the unobstructed decrease in size of the LnO8-coordination polyhedra along the series as Ln3+ ionic radii become smaller towards the heavier Ln-elements. Hence, the structural parameters of the crystal lattice adjust gradually without noticeable strain buildup along the entire series. Besides structural and spectroscopic characterization we applied thermogravimetric analysis and learned that these compounds lose the interstitial water at 180�C.

Isostructural externded series of lanthanide 2-nitroterephthalates

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.