Luminescent Lanthanide Coordination Polymers

Abstract

One-dimensional lanthanide coordination polymers with the formula Ln(isonicotinate)3(H2O)2 (Ln = Ce, Pr, Nd, Sm, Eu, Tb; 1a−f) were synthesized by treating nitrate or perchlorate salts of Ln(III) with 4-pyridinecarboxaldehyde under hydro(solvo)thermal conditions. Single-crystal and powder X-ray diffraction studies indicate that these lanthanide coordination polymers adopt two different structures. While Ce(III), Pr(III), and Nd(III) complexes adopt a chain structure with alternating Ln−(carboxylate)2−Ln and Ln−(carboxylate)4−Ln linkages, Sm(III), Eu(III), and Tb(III) complexes have a doubly carboxylate-bridged infinite-chain structure with one chelating carboxylate group on each metal center. In both structures, the lanthanide centers also bind to two water molecules to yield an eight-coordinate, square antiprismatic geometry. The pyridine nitrogen atoms of the isonicotinate groups do not coordinate to the metal centers in these lanthanide(III) complexes; instead, they direct the formation of Ln(III) coordination polymers via hydrogen bonding with coordinated water molecules. Photoluminescence measurements show that Tb(isonicotinate)3(H2O)2 is highly emissive at room temperature with a quantum yield of ∼90%. These results indicate that highly luminescent lanthanide coordination polymers can be assembled using a combination of coordination and hydrogen bonds. Crystal data for 1a: monoclinic space group P21/c, a = 9.712(2) Å, b = 19.833(4) Å, c = 11.616(2) Å, β = 111.89(3)°, Z = 4. Crystal data for 1f: monoclinic space group C2/c, a = 20.253(4) Å, b = 11.584(2) Å, c = 9.839(2) Å, β = 115.64(3)°, Z = 8.

catena-Poly[[[tetraaqualanthanum(III)]-di-μ-isonicotinato-κ4O:O′] chloride]

“…Herein, we report the synthesis and crystal structure of a new lanthanum complex with isonicotinic ligand. (Mao et al, 1998) and [La(C 6 H 4 NO 2 ) 2 (H 2 O) 4 ](NO 3 ) (Cai et al, 2003), but differs from those found in Ln(isonicotinate) 3 (H 2 O) 2 (Ln = Ce, Pr, Nd, Sm, Eu, Tb) (Ma, Evans et al, 1999), in which the Ln III atoms are bridged by four syn-syn µ-O:O′-carboxylate groups of the isonicotinic ligands (Ln = Ce, Pr, Nd) or coordinated by both two syn-syn µ-O:O′-carboxylate groups and chelating carboxylate groups of the isonicotinic ligands (Ln = Sm, Eu, Tb). To the best of our knowledge, the arrangement in the present complex is rare in the lanthanide analogs.…”

“…For lanthanide complexes with nicotinic acid, isonicotinic acid and isonicotinic acid N-oxide ligands, see : Cai et al (2003); Chen & Fukuzumi (2009) ;Cui et al (1999); Kay et al (1972); Ma et al (1996Ma et al ( , 1999; Mao et al (1998); Starynowicz (1991Starynowicz ( , 1993; Wu et al (2008); Zeng et al (2000); Zhang et al (1999).…”

“…Most of these types of compounds were synthesized by the reaction of rare-earth metal ions with bi-or multi-dentate ligands such as nicotinic acid (Kay et al, 1972;Ma, Hu et al, 1996;Starynowicz, 1991Starynowicz, , 1993, isonicotinic acid (Chen & Fukuzumi, 2009;Ma, Evans et al, 1999;Wu et al, 2008;Zeng et al, 2000) and isonicotinic acid N-oxide (Mao et al, 1998). In the course of research in this area, our extended group has reported several such compounds with different bridging ligands (Cai et al, 2003;Cui et al, 1999;Zhang et al, 1999).…”

One‐Dimensional CdII Coordination Polymers: Solid Solutions with NiII, Thermal Stabilities and Structures

“…[7Ϫ9] Such systems are often tunable by making subtle changes to the reaction conditions, such as the choice of counterion and solution pH, that allow the deliberate design of compounds with luminescent, [10] superconducting [11,12] or magnetic properties [13,14] and also compounds that can be used as nanofibres, [15] in catalysis, [16] in separation processes, [17,18] for gas and liquid storage [19] and in nonlinear optics. [20,21] We have prepared previously one-dimensional coordination polymers of Ni II with aminobenzonitrile isomers and thiocyanate ions as ligands.…”

A novel three-dimensional open framework constructed from infinite chains of edge-sharing CeO8(H2O) polyhedron: [Ce2(ad)3(H2O)2]n

“…There has been much current interesting on the coordination polymers consisting of lanthanide and multifunctional organic ligands for their novel structures and unique properties especially in magnetism, luminescence and catalysis [1][2][3]. Many studies were focus on the construction of higher-dimensional networks by employing the rigid multicarboxylate ligands as building blocks.…”