Novel Luminescent Metal-Organic Frameworks [Eu₂L₃(DMSO)₂(MeOH)₂]·2DMSO·3H₂O and [Zn₂L₂(DMSO)₂]·1.6H₂O (L = 4,4′-Ethyne-1,2-diyldibenzoate)

Abstract

Novel metal-organic frameworks [Eu2L3(DMSO)2(MeOH)2] x 2 DMSO x 3 H2O, 1, and [Zn2L2(DMSO)2] x 1.6 H2O, 2, (L = 4,4'-ethyne-1,2-diyldibenzoate) have been synthesized and structurally characterized. Compound 1 is a 3D open framework while 2 features interpenetrating 2D sheets in the crystal lattice. Both compounds have been characterized with X-ray crystallography, elemental analysis, and thermogravimetric analysis. Compounds 1 and 2 are red and blue-green luminescent, respectively, in the solid state at ambient temperature. Thermogravimetric analysis implies that the extensive interpenetration stabilizes the lattice of 2, although it diminishes the porosity at the same time. The luminescence of 1 can be reversibly quenched and restored by the addition and removal of iodine.

A unique two-dimensional coordination network of 1-benzofuran-2,3-dicarboxylate with lanthanum(III) obtained by solvothermal synthesis

“…As a result, in neutral or weakly basic environments, the coordination potential of this bis-bidentate ligand (with four carboxylate O sites) to metal ions could not fully materialize, in contrast with earlier observations with related bifunctional anions, such as benzene-1,4-dicarboxylate (e.g. Guilera & Steed, 1999;Reineke et al, 2000;Chen et al, 2006;Hu et al, 2007;Pham et al, 2008). We anticipated that possible application of the BFDC unit, as a bidentate or polydentate bridging ligand, in the synthesis of extended coordination networks might require more extreme experimental conditions.…”

“…1. The basic structural unit involves the binuclear [La 2 (COO) 6 ] motif frequently found in coordination frameworks of lanthanide ions and dicarboxylate bridging ligands (Reineke et al, 2000;Chen et al, 2006;Hu et al, 2007;Pham et al, 2008). The asymmetric unit contains two La III ions, three BFDC 2À ligands and four molecules of water ( Fig.…”

“…In BFDC, the ortho-substituted carboxylic acid functions are positioned on one end of the organic ligand, while the other end consists of the aromatic benzene ring. This appears to limit the coordination functionality of this molecule to one or two dimensions (Koner & Goldberg, 2009a,b), as opposed to the three-dimensional coordination frameworks that could be obtained with other ligands, such as benzene-1,4-dicarboxylate, that bear trans-related coordinating functions (Reineke et al, 2000;Chen et al, 2006;Hu et al, 2007;Pham et al, 2008). Within a wider context of our crystal engineering program to design functional metal-organic frameworks, further studies are underway to construct extended coordination polymers with BFDC and related dicarboxylic acid ligands, and various lanthanide ions.…”

A three-dimensional highly stable Zn(II) coordination polymer based on 1,4-benzeneditetrazolate (H2BDT): Synthesis, crystal structure, and luminescent properties

“…According to the reported literature, the free ligand exhibits a broad emission peak at 473 nm [16a]. Therefore, the photoluminescent emission for 2 can be tentatively ascribed to the ligand-to-ligand charge transfer (LLCT) [24].…”

Three-dimensional lanthanide metal-organic frameworks constructed from octahedral secondary building units: Pcu net topology and luminescence

“…The binuclear [Ln 2 (COO) 6 ] motif with four bridging and two chelating carboxylate groups has been recognized in a few discrete complex molecules with monocarboxylate ligands [12] and a limited number of 3-D rare earth MOFs with multicarboxylate ligands [6,13]. The binuclear units can be regarded as six-connecting octahedral SBUs (Fig.…”