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Abstract: Three new lanthanide complexes, [La(HpicO)3(phen)(H2O)] n (1) and Ln3(picO)4(phen)3(H2O)2·HpicO·0.5H2O (Ln=Er (2), Yb (3)) were synthesized by the hydrothermal reactions and characterized by single crystal X-ray diffraction, elemental analysis and IR spectrum. In complex 1, each La(III) ion is 10-coordinated and HpicO− ligands link the metal ions into 1D zigzag chains. Complexes 2 and 3 are isomorphous, and there are three crystallographically independent Ln(III) ions in the asymmetric unit. The N–H⋯O and O–H⋯O hydrogen bonds and π–π stacking interactions in these complexes result in the formation of 3D supramolecular architectures. [Copyright &y& Elsevier]

Single crystal X-ray diffraction shows that [La(gly)2(H2O)2(phen)2(CH3CH2OH)](ClO4)3(phen)3·3H2O (1), [Ln(gly)2(H2O)2(phen)2](ClO4)3 (phen)4·nH2O [n=0, Ln=Nd (2); n=1, Ln=Ho (3)], and [Yb(gly)4(H2O)(phen)](ClO4)4(phen)2(gly+H)·2H2O (4) (gly=glycine, phen=1,10-phenanthroline) with the coordination number 9 for La3+, 8 for Nd3+ and Ho3+, and 7 for Yb3+, exhibit the effect of lanthanide contraction. Complexes 1–4 are all mononuclear structures, with the ligand glycine coordinated to the Ln3+ ion in the monodentate mode and in zwitterionic form. There exist free phen molecules and solvent molecules in the lattice. Therefore, there are different types of hydrogen bonding and π–π stacking interactions in the crystals that give rise to different supramolecular architectures. The structure of 1 is composed of 1D chains which extend in the [1 0 0] direction, while those of 2 and 3 are 2D structures extending in the (0 0 1) plane. However, complex 4 shows a complicated 3D network. [Copyright &y& Elsevier]

Abstract: Two new mixed-ligands lanthanide coordination polymers, [Ln(Ac)(ip)(H2O)2]·0.5H2O (Ln=La (1); Ln=Eu (2); Ac=acetate; ip=isophthalate) have been synthesized under hydrothermal condition. Single-crystal X-ray analyses show that complexes 1 and 2 are three-dimensional structure in which lanthanide ions are bridged by monocarboxylate ligand, acetate or dicarboxylate ligand, isophthalate. And the central lanthanide ions, La3+ and Eu3+, are both nine-coordinate with oxygen atoms. The thermogravimetric analysis was carried out to examine the thermal stability of the title complexes. And the photoluminescence property of complex 2 was also investigated. [Copyright &y& Elsevier]

Abstract: Three new lanthanide coordination polymers with 1,2,4,5-benzenetetracarboxylic acid, Pr2(betc)2(4,4′-bpyH2)·0.25H2O (1), Ln2(betc)2(4,4′-bpyH2) (Ln=Eu (2), Gd (3)) were hydrothermally prepared. The crystallographic data of 1–3 show that they are isostructural, and possess 3D framework with 1D rhomboid channels, where the 4,4′-bipyridine molecules exist steadily via hydrogen bonds. Meanwhile, a supramolecular structure of (4,4′-bpyH2)2(betc) (4) was also obtained by hydrothermal reaction. The results of 1–4 indicate that 4,4′-bipyridine molecule acting as a template plays an important role in the formation of complexes 1–3, and thus has a synergistic action in the construction of 3D framework with large channels. [Copyright &y& Elsevier]

First examples of lanthanide coordination polymers with 4,4′-biphenyldicarboxylic acid (4,4′-H2bpdc), Ln(4,4′-Hbpdc)(4,4′-bpdc)(H2O)2 (Ln=Pr(1), Eu(2), Gd(3)) and Er(4,4′-bpdc)1.5(H2O)2 (4) were prepared by the solvothermal synthesis. Crystallographic data show that complexes 1–3 are isostructural and each lanthanide(III) ion is coordinated to six 4,4′-Hbpdc ligands, and display 3D sandwich structure with lanthanide ion layers and organic ligand layers alternately linking up with each other. Complex 4 shows different coordination modes of 4,4′-bpdc ligands from 1–3 and each Er(III) ion is attached to four 4,4′-bpdc ligands to construct 3D sandwich structure. The emission spectrum of 2 shows one Eu3+ ion site, which is consistent with the results of the X-ray crystal structure analysis. [Copyright &y& Elsevier]

This paper presents three new lanthanide coordination polymers [Pr2(pim)3(phen)2(H2O)]n·3nH2O (1) (H2pim=pimelic acid; phen=1,10-phenanthroline) and [Ln(Hpim)(pim)(phen)]n·1.5nH2O (Ln=Nd, 2; Er, 3) prepared by the hydrothermal reaction. The structural details of complexes 1, 2 and 3 are reported. In complex 1, the Pr(III) ions are bridged by pim in three modes to form 2D layers. Adjacent layers are assembled by hydrogen bonds and π–π stacking between phen ligands into a 3D network. In complex 2, the Nd(III) ions are connected by pim and Hpim in two modes into 1D chains. Hydrogen bonding and π–π stacking between chains result in a 3D supramolecular structure. Single crystal X-ray diffraction analysis shows that complex 3 is isostructural with complex 2. [Copyright &y& Elsevier]

Reported herein are the hydrothermal synthesis and crystal structures of four lanthanide coordination polymers with nitrilotriacetic acid (H3NTA) [Ln(NTA)(H2O)]n (Ln=La, 1; Pr, 2; Nd, 3; Eu, 4). Despite similar syntheses, compounds 1 to 4 show transformation in coordination mode of NTA and coordination number of Ln3+ duo to lanthanide contraction. The Ln(III) ions in 1 and 2 are nine-coordinated and connected through octadentate bridging ligands (NTA) to form a three-dimensional network. The Ln(III) ions in 3 and 4 are eight-coordinated and bridged by heptadentate bridging ligands (NTA) to form an extended two-dimensional layer structure, which further construct a three-dimensional supramolecular structure via coordination bond and three-centered hydrogen bonding between adjacent layers. [Copyright &y& Elsevier]

Three lanthanide coordination polymers were prepared by hydrothermal synthesis and characterized by single-crystal X-ray diffraction. [Pr2(mBDC)3(phen)(H2O)]n·0.5nH2O (1) (mBDC=isophthalate, phen=1,10-phenanthroline) exhibits two kinds of metal environments (coordination numbers 7 and 8). In complex 1, mBDC ligands adopt the tetradentate (bridging and bridging) coordination mode and connect Pr ions into an undulating layer, and a 3D supramolecular structure is formed via hydrogen bonds between adjacent layers. [Tb4(mBDC)6(phen)]n (2) has three types of metal environments (coordination numbers 6, 7 and 8) and is composed of a 3D network formed by mBDC linking Tb ions via tetradentate (bridging and bridging) and pentadentate (bridging/chelating and bridging) coordination modes. There are two kinds of small quadrilateral channels along the a-axis. [Er4(mBDC)6(phen)]n (3) is isostructural to complex 2. [Copyright &y& Elsevier]

Abstract: Three new lanthanide coordination polymers based on mixed acid ligands [Ln(oba)(ox)0.5(H2O)2] n (Ln=Y (1); Er (2); Yb (3). H2oba=4,4′-oxybis (benzoic acid); H2ox=oxalic acid) were prepared by hydrothermal reactions and characterized by single-crystal X-ray diffraction. In these complexes, lanthanide ions are bridged by oba ligands to form 1D double-stranded chains, which are further connected by ox ligands, resulting in the formation of 2D (4,4) grids. The upconversion emission of the Y:Er–Yb co-doped coordination polymer was studied and the unusual blue emission for the Er(III) complexes was observed, which arises from the 2H9/2 → 4I15/2 transition and can be explained by three-photon excitation mechanism which is mostly phonon-dependent. The introduction of the oxalate anion without high-energy vibrational groups is beneficial to the increasing intensity of upconversion fluorescence. The magnetic properties of complexes 2 and 3 were investigated. The decrease of χ M T over the temperature range of 300–2K and the negative value of θ are due primarily to the splitting of the ligand field of the ErIII and YbIII ions together with the possible weak antiferromagnetic coupling between the rare earth ions. [Copyright &y& Elsevier]

Abstract: Porous lanthanide coordination polymers, {[Ln2(atpt)3(H2O)2]·0.5(4,4′-bpy)(H2O)} n [Ln=Eu(1), Gd(2), Yb(3), H2atpt=2-aminoterephthalic acid, 4,4′-bpy=4,4′-bipyridine] were obtained by hydro-solvothermal reaction, in which 4,4′-bpy acts as template. For the first time the nitrogen atom of an atpt ligand coordinates to metal ions in 1–3. The photophysical properties and thermal stability of 1 were investigated. [Copyright &y& Elsevier]

Abstract: Three new polynuclear lanthanide coordination polymers [Ln5(μ3-OH)(oba)7(H2O)2] n ·0.5nH2O (Ln=Eu (1), Ho (2)) and [Yb6(oba)9(H2O)] n (3) (H2oba=4,4′-oxybis(benzoic acid)), were prepared by hydrothermal reactions. 1 and 2 are isomorphous and exhibit complicated three-dimensional structures based on [Ln5(μ3-OH)(oba)7(H2O)2] building blocks. In the asymmetric unit, there are five different coordination environments of Ln(III) ions, including a trinuclear hydroxo core. Complex 3 is a three-dimensional coordination polymer built up from a hexanuclear building block. In 3, Yb(III) ions have six different chemical environments and are in a regular arrangement, resulting in pseudohexagonal prisms along the a-axis. The luminescent property of 1 and magnetic behaviors of 2 and 3 have also been studied. [Copyright &y& Elsevier]