9 research outputs found

    Structural Variation and Preference in Lanthanide-pyridine-2,6-dicarboxylate Coordination Polymers

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    Ten lanthanide coordination polymers were designed and synthesized using pyridine-2,6-dicarboxylic acid (H<sub>2</sub>pdc) and two different heating techniques (conventional and microwave): [Ln­(pdc)­(H<sub>2</sub>O)<sub>4</sub>]<sub>3</sub>­·3Cl {<i>Pa</i>3̅; Ln = Pr (<b>I</b>), Nd (<b>II</b>), Sm (<b>III</b>), Eu (<b>IV</b>), and Gd (<b>V</b>)}, [Ln­(pdc)­(Hpdc)­(H<sub>2</sub>O)<sub>2</sub>]­·3H<sub>2</sub>O {<i>P</i>2<sub>1</sub>/<i>c</i>; Ln = Pr (<b>VI</b>), Nd (<b>VII</b>), and Sm (<b>VIII</b>)} and [Ln­(pdc)­(H<sub>2</sub>O)<sub>4</sub>]<sub>3</sub>­·3Cl {<i>Ia</i>3̅; Ln = Sm (<b>IX</b>), and Eu (<b>X</b>)}. These complexes show variation in structures depending on the heating technique and the lanthanide ions. They can be classified into the cubic <i>Pa</i>3̅ (<b>I</b>–<b>V</b>) and <i>Ia</i>3̅ (<b>IX</b>, <b>X</b>), and the monoclinic <i>P</i>2<sub>1</sub>/<i>c</i> (<b>VI</b>–<b>VIII</b>) complexes. The cubic complexes exhibit supramolecular isomerism and a tubular three-dimensional structure of interpenetrated <b>lcs</b> and <b>pcu</b> net topologies, while the monoclinic complexes are the supramolecular assemblies of the one-dimensional chains. As the cubic <i>Pa</i>3̅ structures are favored by the use of the microwave, there is variation in structures as conventional heating was employed, although the cubic <i>Pa</i>3̅ structures are still the most favored except for the <b>VI</b> case. The title complexes showed moderate thermal stabilities. The organic ligand is revealed to be a modest sensitizer to initiate the photoluminescence in the title complexes

    Base-Directed Formation of Isostructural Lanthanide–Sulfate–Glutarate Coordination Polymers with Photoluminescence

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    A series of five isostructural 3D lanthanide-based coordination polymers [LnIII2(H2O)6(glu)(SO4)2]n [Ln = Pr(1), Nd(2), Sm(3), Eu(4), and Gd(5)] was effortlessly obtained within a few minutes via the microwave-heating method. The employment of auxiliary bases, that is, sodium hydroxide, 4,4′-bipyridine, and 1,4-diazabicyclo[2.2.2]octane, led to the formation of the title complex, whereas base-free synthesis yielded a three-dimensional inorganic coordination polymer, [Ln2(H2O)4(SO4)3]n·nH2O, Ln = Nd (2a). The robustness of the synthetic method was illustrated as both microwave-heating and conventional hydrothermal techniques also enabled the formation of a high-crystalline phase-pure complex 1–5. In the structure of 1–5, glutarato (glu2–) and sulfato ligands link dinuclear Ln(III) building units into three-dimensional frames. The glu2– ligands act as tethering linkers, expanding the structure into a neutral 3D coordination network. Hydrogen bonds were found to be the predominant intermolecular interactions in the crystal structures. Photoluminescence of the complex 1–5 was studied

    Base-Directed Formation of Isostructural Lanthanide–Sulfate–Glutarate Coordination Polymers with Photoluminescence

    No full text
    A series of five isostructural 3D lanthanide-based coordination polymers [LnIII2(H2O)6(glu)(SO4)2]n [Ln = Pr(1), Nd(2), Sm(3), Eu(4), and Gd(5)] was effortlessly obtained within a few minutes via the microwave-heating method. The employment of auxiliary bases, that is, sodium hydroxide, 4,4′-bipyridine, and 1,4-diazabicyclo[2.2.2]octane, led to the formation of the title complex, whereas base-free synthesis yielded a three-dimensional inorganic coordination polymer, [Ln2(H2O)4(SO4)3]n·nH2O, Ln = Nd (2a). The robustness of the synthetic method was illustrated as both microwave-heating and conventional hydrothermal techniques also enabled the formation of a high-crystalline phase-pure complex 1–5. In the structure of 1–5, glutarato (glu2–) and sulfato ligands link dinuclear Ln(III) building units into three-dimensional frames. The glu2– ligands act as tethering linkers, expanding the structure into a neutral 3D coordination network. Hydrogen bonds were found to be the predominant intermolecular interactions in the crystal structures. Photoluminescence of the complex 1–5 was studied

    Base-Directed Formation of Isostructural Lanthanide–Sulfate–Glutarate Coordination Polymers with Photoluminescence

    No full text
    A series of five isostructural 3D lanthanide-based coordination polymers [LnIII2(H2O)6(glu)(SO4)2]n [Ln = Pr(1), Nd(2), Sm(3), Eu(4), and Gd(5)] was effortlessly obtained within a few minutes via the microwave-heating method. The employment of auxiliary bases, that is, sodium hydroxide, 4,4′-bipyridine, and 1,4-diazabicyclo[2.2.2]octane, led to the formation of the title complex, whereas base-free synthesis yielded a three-dimensional inorganic coordination polymer, [Ln2(H2O)4(SO4)3]n·nH2O, Ln = Nd (2a). The robustness of the synthetic method was illustrated as both microwave-heating and conventional hydrothermal techniques also enabled the formation of a high-crystalline phase-pure complex 1–5. In the structure of 1–5, glutarato (glu2–) and sulfato ligands link dinuclear Ln(III) building units into three-dimensional frames. The glu2– ligands act as tethering linkers, expanding the structure into a neutral 3D coordination network. Hydrogen bonds were found to be the predominant intermolecular interactions in the crystal structures. Photoluminescence of the complex 1–5 was studied

    Synergistic Induction of Solvent and Ligand-Substitution in Single-Crystal to Single-Crystal Transformations toward a MOF with Photocatalytic Dye Degradation

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    External-stimuli responsiveness as found in natural organisms and smart materials is attractive for functional materials scientists who attempt to design and imitate fascinating behavior into their materials. Herein, we report a couple of new solvent-responsive isostructural two-dimensional cationic metal–organic frameworks (MOFs) of Mn(II) (1a) and Zn(II) (2a) that undergo unprecedented single-crystal to single-crystal (SCSC) transformation toward the corresponding isostructural three-dimensional MOFs of Mn(II) (1b) and Zn(II) (2b). The 2D MOFs 1a and 2a have been effortlessly and rapidly synthesized via the microwave-heating technique. The SCSC transformations are synergistically induced by solvent and ligand-substitution reactions and able to be triggered by water, methanol, ethanol, and n-propanol. Time-dependent SCSC transformations were studied by in situ X-ray diffraction. Investigations on photodegradation of methyl orange showed that Zn-MOF 2b has higher efficiency than Mn-MOF 1b under UV–C irradiation at 300 min, 94.27%, and 21.91%, respectively. The influence of charge on the dye molecules, heterogeneity of the catalysis, and •OH radical-scavenging test was studied. First-principles computations suggest that the high photocatalytic activity of 2b may be attributed to its suitable band-edge position for redox reactions

    Synergistic Induction of Solvent and Ligand-Substitution in Single-Crystal to Single-Crystal Transformations toward a MOF with Photocatalytic Dye Degradation

    No full text
    External-stimuli responsiveness as found in natural organisms and smart materials is attractive for functional materials scientists who attempt to design and imitate fascinating behavior into their materials. Herein, we report a couple of new solvent-responsive isostructural two-dimensional cationic metal–organic frameworks (MOFs) of Mn(II) (1a) and Zn(II) (2a) that undergo unprecedented single-crystal to single-crystal (SCSC) transformation toward the corresponding isostructural three-dimensional MOFs of Mn(II) (1b) and Zn(II) (2b). The 2D MOFs 1a and 2a have been effortlessly and rapidly synthesized via the microwave-heating technique. The SCSC transformations are synergistically induced by solvent and ligand-substitution reactions and able to be triggered by water, methanol, ethanol, and n-propanol. Time-dependent SCSC transformations were studied by in situ X-ray diffraction. Investigations on photodegradation of methyl orange showed that Zn-MOF 2b has higher efficiency than Mn-MOF 1b under UV–C irradiation at 300 min, 94.27%, and 21.91%, respectively. The influence of charge on the dye molecules, heterogeneity of the catalysis, and •OH radical-scavenging test was studied. First-principles computations suggest that the high photocatalytic activity of 2b may be attributed to its suitable band-edge position for redox reactions

    Ligand-Substitution-Induced Single-Crystal to Single-Crystal Transformations in a Redox-Versatile Cu(II) MOF toward Smartphone-Based Colorimetric Detection of Iodide

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    Fabrication of a new three-dimensional Cu(II) metal–organic framework, {[Cu4(4,4′-bipy)3(OH)2(mal)3]·4H2O}n (1a; 4,4′-bipy = 4,4′-bipyridine, H2mal = malonic acid; P21/m), that undergoes an unprecedented redox-versatile ligand-substitution-induced single-crystal to single-crystal transformation, for smartphone-based detection of iodide was studied. The Cu-MOF 1a has been effortlessly synthesized by the microwave-heating technique. Phase formation of the Cu-MOF 1a depended on counter-anions. The transformations can be triggered by halides to corresponding coordination polymers through both non-redox and redox-associated pathways. The changes in the local structure and oxidation state of copper during the transformation were studied by ex situ and in situ synchrotron X-ray absorption spectroscopies. The selectivity of the halide-triggered transformation was investigated. A study on smartphone-based colorimetric detection of iodide was found to be linearly proportional to the iodide concentration in the range 10–1500 mg/L with a limit of detection of 5 mg/L and good precision relative standard deviation of 1.9% (n = 11), possibly to construct the iodide test kit

    Ligand-Substitution-Induced Single-Crystal to Single-Crystal Transformations in a Redox-Versatile Cu(II) MOF toward Smartphone-Based Colorimetric Detection of Iodide

    No full text
    Fabrication of a new three-dimensional Cu(II) metal–organic framework, {[Cu4(4,4′-bipy)3(OH)2(mal)3]·4H2O}n (1a; 4,4′-bipy = 4,4′-bipyridine, H2mal = malonic acid; P21/m), that undergoes an unprecedented redox-versatile ligand-substitution-induced single-crystal to single-crystal transformation, for smartphone-based detection of iodide was studied. The Cu-MOF 1a has been effortlessly synthesized by the microwave-heating technique. Phase formation of the Cu-MOF 1a depended on counter-anions. The transformations can be triggered by halides to corresponding coordination polymers through both non-redox and redox-associated pathways. The changes in the local structure and oxidation state of copper during the transformation were studied by ex situ and in situ synchrotron X-ray absorption spectroscopies. The selectivity of the halide-triggered transformation was investigated. A study on smartphone-based colorimetric detection of iodide was found to be linearly proportional to the iodide concentration in the range 10–1500 mg/L with a limit of detection of 5 mg/L and good precision relative standard deviation of 1.9% (n = 11), possibly to construct the iodide test kit

    Data_Sheet_1_Life on the wall: the diversity and activity of microbes on 13th – century AD. Lan Na mural painting.PDF

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    Diverse microorganisms from the three domains of life (Archaea, Bacteria, and Eukaryota) cause deterioration in mural paintings worldwide; however, few studies have simultaneously targeted these three domains. This study aims to survey the microbiome and its potential for biodeterioration on unpreserved Lan Na mural paintings in Sean Khan temple, Chiang Mai, Thailand. The overview of the archaeal, bacterial, and fungal communities was reported by Illumina sequencing, whereas the potential for deterioration was revealed by culturable techniques and a literature search. The abundant microbes reported in this study were also found in other ancient mural paintings worldwide. Halococcus, a salt-tolerant archaeon, as well as the eubacterial genus Crossiella dominated the prokaryotic community. On the other hand, the main fungal group was the genus Candida (Ascomycota). However, a low number of fungi and bacteria were isolated. Most of the isolates showed the ability to survive in the drought conditions of mural paintings but could not perform discoloration activities. The deterioration activity mainly affected calcium compounds, which are the main components of painting substrates. Aspergillus and several bacterial isolates could dissolve calcium compounds, but only Trichaptum species could induce crystal formation. These results suggest that deterioration of painting substrate should be taken into consideration in addition to deterioration of color in mural paintings. For the Lan Na painting in Sean Khan temple, the plaster is the prime target for biodeterioration, and thus we suggest that the preservation effort should focus on this component of the mural painting.</p
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