DOI: 10.1002/chem.200802589 Lanthanide-Based Coordination Polymers Assembled by a Flexible Multidentate Linker: Design, Structure, Photophysical Properties, and Dynamic Solid-State Behavior Claire Marchal, [a] Yaroslav Filinchuk, [b] Xiao-Yan Chen, [a] Daniel Imbert, [a] and Marinella Mazzanti* [a] Introduction Metal–organic frameworks (MOFs) based on rare-earth metal elements are attracting increasing attention due to their ability to form multifunctional materials that combine desirable structural features with the interesting magnetic, optical, and catalytic properties of the lanthanide ions. [1–5] Notably, because of their interesting photophysical proper- ties (characteristic sharp emission, long lifetime, large Stokes shift), [6] lanthanide-based coordination polymers are excellent candidates for the development of light-emitting diodes [7] and sensors. [8] Recently, several lanthanide coordi- nation polymers with interesting photophysical properties, a few of which couple luminescence and porosity, have been reported. [9–16] However, lanthanide systems remain far less studied than frameworks based on d-block transition-metal elements [17–20] because the typically unspecific coordination properties of the lanthanide ions render the design of lan- thanide-based coordination frameworks with specific prop- erties very challenging. By contrast, the coordination flexi- bility of lanthanide ions can lead to unusual structural topol- ogies and new framework families. [3] The majority of the re- ported lanthanide frameworks are formed by using low-den- ticity rigid organic building blocks. Because of the lack of a preferred coordination number or geometry of the lantha- nide ions, the final structure remains difficult to predict in such a synthetic approach, thus preventing a systematic in- vestigation of structure–property relations. Moreover, low- denticity linkers often result in the presence of solvent mol- ecules coordinated to the metal ion that lead to lumines- cence quenching and low thermal stability. Abstract: Four picolinate building blocks were implemented into the mul- tidentate linker N,N’,N’-tetrakis[(6-car- boxypyridin-2-yl)methyl]butylenedi- ACHTUNGTRENNUNGamine (H 4 tpabn) with a linear flexible spacer to promote the assembly of lan- thanide-based 1D coordination poly- mers. The role of the linker in directing the geometry of the final assembly is evidenced by the different results ob- tained in the presence of Htpabn 3À and tpabn 4À ions. The tpabn 4À ion leads to the desired 1D polymer {[Nd- ACHTUNGTRENNUNG(tpabn)]H 3 O·6 H 2 O} 1 (12). The Htpabn 3À ion leads to the assembly of Tb III and Er III ions into 1D zigzag chains of the general formula {[M- ACHTUNGTRENNUNG(Htpabn)]·x H 2 O} 1 (M = Tb, x = 14 (1); M = Tb, x = 8(11); M = Er, x = 14 (2); M = Er, x = 5.5 (4)), a 2D network is formed by the Eu III ion (i.e., {[Eu- ACHTUNGTRENNUNG(Htpabn)]·10 H 2 O} 1 (7)), and both supramolecular isomers (1D and 2D) are obtained by the Tb III ion. The high flexibility of the polymeric chains re- sults in a dynamic behavior with a sol- vent-induced reversible structural tran- sition. The Tb III - and Eu III -containing polymers display high-luminescence quantum yields (38 and 18 %, respec- tively). A sizeable near-IR lumines- cence emission is observed for the Er III - and Nd III -containing polymers when lattice water molecules are re- moved. Keywords: chromophores · lantha- nides · luminescence · polymers · supramolecular chemistry [a] Dr. C. Marchal, Dr. X.-Y. Chen, Dr. D. Imbert, Dr. M. Mazzanti Laboratoire de Reconnaissance Ionique et Chimie de Coordination Service de Chimie Inorganique et Biologique (UMR-E 3 CEA-UJF) CEA/DSM/INAC, CEA-Grenoble 38054 Grenoble, Cedex 09 (France) [b] Dr. Y. Filinchuk Swiss–Norwegian Beam Lines (SNBL) European Synchrotron Radiation Facility (ESRF) rue Jules Horowitz, 38043 Grenoble (France) Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/chem.200802589. Chem. Eur. J. 2009, 15, 5273 – 5288  2009 Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim 5273 FULL PAPER