Molecular structures lanthanide-coordination chemistry

Figure 3.10 Structures of (a) [YL3(H20)2]4 (HL = -hydoxybenzoic acid) and (b) [LuL4]4 (HL = acetic acid) [RE, black O, grey C, white H, omitted], (Redrawn from the CIF files of M.S. Khiyalov et al, Crystalline and molecular structure of (p-hydroxybenzoato)yttrium(III), Koordi-natsionnaya Khimiya (Coordination Chemistry) (in Russian), 7 (8), 1255-1261, 1981 [49] and A. Lossin and G. Meyer, Ternary acetates of the lanthanides with cesium dimers in CsLu(CH3COO)4 and trimers in Cs2[Lu3(CH3COO)io(OH)(H20)]. Synthesis, crystal structures, thermolysis, Zeitschriftfur Anorganische undAllgemeine Chemie, 619 (8), 1465-1473, 1993 [52].)...

Figure 3.2S The structure of (a) [Dy(H20)(DTPA)] and (b) [Dy2(DTPA)2] [Dy, black (large balls) O, grey N, black (small balls) C, white H, omitted)]. (Redrawn from the CIF files of J. Wang et al, Syntheses and structural determinations of the nine-coordinate rare earth metal Na4[Dy "(dtpa)(H20)]2 l6H20, Na[Dy "(edta)(H20)3]-3.25H20 and Na3[Dy (nta)2(H20)]-5.5H20, Journal of Coordination Chemistry, 60 (20), 2221-2241, 2007 [106] and Y. Inomata, T. Sunakawa and F.S. HoweU, The syntheses of lanthanide metal complexes with diethylenetriamine-N, N, N, N", N"-pentaacetic acid and the comparison of their crystal structures, Journal of Molecular Structure, 648 (1-2), 81-88, 2007 [107].)...

Ultimately, the chemistry of lanthanide-containing MOFs and CPs can be regarded as a blend between the coordination chemistry of molecular and solid-state materials. The structural themes present in solid-state materials (e.g., edge sharing of polyhedra) and the coordination preferences seen in molecular compounds (e.g., N-, O- donors) are essentially what form the structural basis for extended topologies. 

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. 

Simple CH-alkoxides continue to reveal surprising new structure chemistry and the composition of Ln(OMe)3 and Ln(OEt)3 is not yet determined. Mononuclear lanthanide aryloxide complexes are well-examined and are the only fully characterized 3-coordinate, homoleptic Ln(OR)3 species. The variation of the steric environment in pure CH- and CHF-alkoxides with respect to volatility (molecular mass optimization) seems to be rather exhausted. It was shown that functionalization can ensure volatility and although the entire MOCVD-busi-ness gets somewhat stuck, CHF- and CHdo-alkoxides are promising alternatives to the /J-diketonates. Sol gel technology can fall back on highly soluble CH- and CHdo-alkoxides. 

James (16), Kitigawa and co-workers (17-19), Wuest (20), and Chen and coworkers (21) explore the chemistry, structures, and properties of MOFs and CPs from a variety of perspectives. Indeed, a recent special issue of the Journal of Solid State Chemistry was dedicated to these very topics (22). One wiU notice almost immediately that this field is dominated by materials based on block transition metal compositions. Lanthanide (Ln)-containing materials have been much scarcer, perhaps for reasons to be discussed herein (e.g., a tendency to exhibit higher coordination numbers) (23). With this in mind, however, recent advances in polymeric Ln-containing materials suggest that these compounds are as structurally diverse and that the unique luminescence behavior of the /-elements may be harnessed for applications, such as sensing and molecular recognition (23-30). Such inherent properties may extend the applications of framework materials beyond those introduced above. 

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