Lanthanides, coordination polymers molecular materials

The luminescence properties of lanthanide complexes can be enhanced by design of chemical structures. However, the correlation between coordination structures and luminescence properties of lanthanide complexes has been scarcely investigated. In this thesis, the correlation between coordination structures and photophysical properties of lanthanide complexes with phosphine oxide ligands were demonstrated. Additionally, functionalization of lanthanide compounds was also described in terms of lanthanide coordination polymers. This thesis gives the first systematic studies on molecular photo-science between lanthanideflll) coordination chemistry and photo-functional materials science. 

This section describes systems which are at the border of what has been defined as being the scope of this review and therefore does not pretend to be comprehensive. Indeed, if there is a wealth of strictly inorganic materials and glasses into which NIR-crnitting lanthanide ions have been incorporated and which are clearly excluded from the review, there also exist a continuum between these materials and molecular entities, for instance coordination polymers and clusters which have been described in the two preceding sections. In continuity with these concepts are micro- and mesoporous materials into which lanthanide salts or complexes can be incorporated or attached. These are essentially zeolites and sol-gel materials, either conventional or the so-called inorganic-organic hybrids, as well as polymers. 

The anhydrous compound, whose chemical formula is Er(btc), has not been structurally characterized because of its lack of crystallinity and its physical properties have not been explored in details. This family is characteristic of the problem encoimtered when trying to constmct molecular based microporous materials, that is obstmction of the pores by interpenetration of networks or collapse of the stracture upon removal of the guest molecules intercalated in the cavities. This problem is, of course, also present for coordination polymers based on transition elements but it is much more crucial for lanthanide-based materials. Indeed, lanthanide ions present a high coordination number (generally ranging between 7 and 12) and their coordination sphere most often contains some solvent molecules. These coordination water molecules, when removed upon dehydration, lead to structural rearrangements and, sometimes, to a loss of the microporons character. 

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