Crystal structures and gas adsorption behavior of new lanthanide-benzene-1,4-dicarboxylate frameworks

Abstract

Six new lanthanide metal organic complexes, i.e. [La2(NO2-BDC)3(H2O)4] (1)[Ln(L)0.5(NO2-BDC)(H2O)] • 3H2O (Ln = Eu (2), Tb (3), Dy (4) and Ho (5); L = BDC 2or BDC 2-/NO2-BDC 2-) and [Tm(NO2-BDC)1.5(H2O)]•H2O (6), have been synthesized using mixed ligands of benzene-1,4-dicarboxylic acid (H2BDC) and the in situ generated 2-nitrobenzene-1,4-dicarboxylic acid (NO2-BDC 2-). Single crystal structures and topologies of the complexes are presented based on the single crystal X-ray diffraction and spectroscopic data.Whilst the structures of 1 and 6 contain negligible voids, the frameworks of 2-5 are microporous in nature and stable upon the removal of all the water molecules from the structures and thermal treatment to over 400 C. Based on the study of 2, significant adsorption capacities for carbon dioxide (95 cm 3 •g -1 or 4.2 mmol•g -1 ) and hydrogen (79 cm 3 •g -1 or 4 mmol•g -1 ), as well as the remarkable stability of the framework upon the sorption/desorption experiments are revealed.

Gas Adsorption, Proton Conductivity, and Sensing Potential of a Nanoporous Gadolinium Coordination Framework

“…Owing to the substitutional disorder, atoms O8, O9, O13, and O19 were attributed to both The in situ generation of nitrite from nitrate can be assumed under the highly acidic solvo-/hydrothermal conditions (Figure S5). 27,44 The other partially occupied di-nitro-BPDC 2− exhibits similar substitutional disorder but with water molecules, leading to the possibility for atoms O10, O25, O28, and O34 to be from both carboxyl groups, i.e. O25−C28−O28 and O10−C41−O34, and four independent water molecules.…”

“…The presence of the nitro group should also be considered for the benefit of CO 2 adsorption. 27 On the basis of a literature survey, 29−32 few nanoporous frameworks of lanthanides can be afforded by using H 2 BPDC and its derivatives, although the successful synthesis depends critically on the synthesis conditions. Apparently, H 2 BPDC and its derivatives such as 2,6,2′,6′-tetranitrobiphenyl-4,4′-dicarboxylic acid can also provide flexible frameworks with substantial stability upon a change in guest molecules.…”

“…nitrite anion, was introduced through in situ generation. The presence of the nitro pendants on di-nitro-H 2 BPDC should help promoting both the interaction with CO 2 27 and the transportation of protons through hydrogenbonding interactions. 18 The CO 2 adsorption behavior and the proton superconductivity of the single crystals and therefore their potentials in temperature and humidity sensing are reported and discussed.…”

“…The fabrication of nanoporous MOFs, particularly those based on the lanthanides, has been a challenge due to the high coordination number and flexible coordination geometry of the lanthanides. Following our success in the use of rigid and linear benzene-1,4-dicarboxylic acid and 2-nitrobenzene-1,4-dicarboxylic acid in the design and synthesis of microporous LnCPs, , we assumed that the employment of a linear and rigid biphenyl-4,4′-dicarboxylic acid (H 2 BPDC) having a similar but longer backbone should provide nanoporous frameworks. The presence of the nitro group should also be considered for the benefit of CO 2 adsorption .…”

Metal–organic frameworks for carbon dioxide capture

“…123 Also, in IRMOF series and in MTV-MOF-5-EHI, the incorporation of NO 2 groups was a common technique for best-performing CO 2 adsorption. 124,125 The insertion of different functional groups in UiO-66(Zr)-X (X = -Br, -NH 2 , -NO 2 , -(CF 3 ) 2 , -(OH) 2 , -SO 3 H, and -CO 2 H) suggested that, in accordance with the polarity trend of the functional group, SO 3 H and CO 2 H groups possess the highest CO 2 selectivity, good working capacities, and medium-ranged CO 2 adsorption enthalpy. Additionally, the geometry of the UiO-66(Zr)-SO 3 H and UiO-66(Zr)-CO 2 H allows direct interaction between the inserted groups and CO 2 .…”