ARTICLE DOI: 10.1002/zaac.200900300 Two-Dimensional Lanthanide-Containing Coordination Frameworks: Structure, Magnetic and Luminescence Properties Ting Gao, [a,b] Guang-Ming Li, [a,b] Peng-Fei Yan,* [a,b] Ju-Wen Zhang, [a,b] Wen-Bin Sun, [a,b] Masayuki Suda, [c] and Yasuaki Einaga* [c] Keywords: Salen; Lanthanides; Magnetic properties; Luminescence; Polymers Abstract. Two lanthanide-containing 2D coordination polymers, [Ln(H 2 salen) 1.5 (NO 3 ) 3 ] n [H 2 salen = N,N'- ethylenebis(salicylideneim- ine); Ln = Gd (1), Dy (2)], have been prepared by self-assembly method. The molecular magnetism and luminescence of the metal Introduction Lanthanide complexes are currently of great interest because of their unique physicochemical properties and various appli- cations as new materials [1]. Especially, the luminescence [2] and magnetism [3] of lanthanide complexes have aroused much attention recently. The lanthanide ions have narrow emission bands and relatively long luminescence lifetimes as a result of transitions within the partially filled 4f shell of the ions [4]. Lanthanide complexes are the most employed for ap- plications such as fluoroimmunoassays and fluorescence mi- croscopy [5]. In addition, lanthanide ions have long been ex- ploited to influence the properties of magnets by introducing anisotropic contributions [6]. Since few simple compounds containing magnetically coupled f-block ions were available, little is known about the nature of the exchange interactions among rare earth ions and other magnetic groups. Generally, the interaction between the adjacent lanthanide ions is ferro- magnetic or antiferromagnetic in nature [7]. In the past years, few homodinuclear or homopolynuclear lanthanide complexes have been reported and their magnetic behaviors were found to be ferromagnetic or antiferromagnetic interactions between the Ln···Ln ions because of the different bridging ligands or atoms [8]. Typical salen ligands, tetradentate Schiff bases de- rived from salicylaldehyde and diamines with two N-donor and two O-donor chelating centers suitable for the lanthanide ions * Prof. Dr. P.-F. Yan E-Mail: yanpf@vip.sina.com * Prof. Dr. Y. Einaga E-Mail: einaga@chem.keio.ac.jp [a] Key Laboratory of Functional Inorganic Chemistry Heilongjiang University Harbin 150080, P. R. China [b] School of Chemistry and Materials Science Heilongjiang University Harbin 150080, P. R. China [c] Department of Chemistry Keio University Yokohama 223–8522, Japan 624 © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Z. Anorg. Allg. Chem. 2010, 636, 624–628 complexes had been studied. Complex 1 exhibits antiferromagnetic in- teraction between spin carriers. Complex 2 emits the H 2 salen ligand luminescence. to form homodinuclear [9] or homopolynuclear complexes [10]. As a contribution to the understanding of the molecular mag- netism and luminescence of lanthanide complexes with flexi- ble salen ligands, we present herein the synthesis, structural, luminescence, and magnetic properties of two 2D complexes based on the salen ligand N,N'-ethylenebis(salicylideneimine), generally formulated as [Ln(H 2 salen) 1.5 (NO 3 ) 3 ] n [Ln = Gd (1), Dy (2)]. Although a number of salen and salen-like lanthanide complexes with different compositions have been reported de- pending on the preparative procedures, to the best of our knowledge, structurally characterized salen and/or salen-like lanthanide complexes are rare [11]. The coordination modes of salen and/or salen-like ligand are usually proposed on the basis of the spectroscopic data [12]. Results and Discussion Synthesis and Characterization Reactions of the salen ligand with Ln(NO 3 ) 3 ·6H 2 O in a molar ratio of 1:1 were carried out in MeOH/CH 2 Cl 2 at ambient tem- perature. Methylene dichloride was employed to increase the solubility of salen ligand. The immediate color change of the solution upon addition of Gd(NO 3 ) 3 ·6H 2 O and Dy(NO 3 ) 3 · 6H 2 O indicates instant occurrence of the coordination reaction. Single crystals suitable for X-ray analysis were obtained by slow diffusion of ethyl ether into the methanol solution of the powder sample. Complexes 1 and 2 are stable in air and mod- erately soluble in polar organic solvent such as methanol, etha- nol, and DMF. X-ray crystal analyses reveal that one type co- ordination complexes, [Ln(H 2 salen) 1.5 (NO 3 ) 3 ] n [Ln = Gd (1), Dy (2)] (Scheme 1) are isolated.