Spontaneous Assembly of d−f Coordination Frameworks: Syntheses, Structures, and Photoluminescence

Abstract

A series of new d−f heterometallic coordination frameworks, namely, [LnM(Hbic)2(ox)H2O]·2H2O [Ln = Nd, M = Cu (1); Ln = Eu, M = Ag (2); Ln = Tb, M = Ag (3); H2bic = 1H-benzimidazole-5-carboxylic acid; ox = oxalate] for type I, [LnCu(Hbic)3(ox)0.5]·H2O [Ln = Sm (4), Ln = Dy (5)] for type II, and [LnAg(Hbic)(ox)1.5] [Ln = Eu (6)] for type III, were successfully synthesized by using different metal salts and rationally controlling reaction temperature. Complexes 1−3 represent 1D polymeric chain architectures that are constructed from the connections between lanthanide-oxalate chains and M(Hbic)2 subunits. Complexes 4 and 5 are 2D layered structures which are assembled by lanthanide-oxalate and Cu(Hbic)3 units. Complex 6 exhibits another 2D layered coordination framework that is built up by tetranuclear Eu2Ag2 clusters and mixed ox and Hbic linkers. The polymeric coordination frameworks of complexes 1−6 are sustained by both hydrogen bonding and π−π stacking interactions, and they are self-assembled to form the 3D supramolecular frameworks.

Ln-Ag heterometallic coordination polymers

“…To our knowledge, only a few examples of 1D coordination polymers based on Ln-Ag mixed-metal ions have been reported (Goodname et al 1992, He and Han 2007, Gerasko et al 2008, Zhao et al 2008, Cai et al 2009b, Lian et al 2009, Peng et al 2010, Ma et al 2010, Zou et al 2011, and the ligands used are 2,6-pyridinedicarboxylic acid (H 2 PDA), nicotinic acid (HNIC), and isonicotinic acid (HINA). Noticeably, Goodname and coworkers reported the first structurally characterized Ln-Ag heterometallic coordination polymer, Ag[Gd(PDA) (Goodname et al 1992), which features a 1D structure based on 2,6-pyridinedicarboxylic acid.…”

Heterometallic Complexes Containing Lanthanides

“…transition metal ions such as Ag + and Cu + [20]. This approach shows advantages in that the coordination network forms by simple self-assembly in the solid state and is entirely predictable on the basis of the ligand structure and the metal ions employed.…”

catena-Poly[[diaquabis{μ2-3,5-bis[(pyridin-4-yl)methylamino]benzoato}nickel] monohydrate]

“…For the use of N-, or O-multidentate donor ligands as building blocks in the construction of infinite frameworks, see: Peng et al (2010). For related structures, see : Chen et al (2009); Kuai et al (2011).…”

“…One of the effective strategies for construction of such polymers is to select suitable multidentate organic ligands as building blocks to link metal centers into infinite framework. Among popularly employed organic ligands, N-, or O-multidentate donor ligands are regarded as excellent candidates for building the blocks of desirable frameworks (Peng et al, 2010). Herein, we report the crystal structure of the title coordination polymer.…”