| 1. |
- Benecke, Jannik, et al.
(author)
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Polymorphous Indium Metal-Organic Frameworks Based on a Ferrocene Linker : Redox Activity, Porosity, and Structural Diversity
- 2020
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In: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 59:14, s. 9969-9978
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Journal article (peer-reviewed)abstract
- The metallocene-based linker molecule 1,1'-ferrocenedicarboxylic acid (H(2)FcDC) was used to synthesize four different polymorphs of composition [In(OH)(FeC12H8O4)]. Using conventional solvent-based synthesis methods and varying the synthetic parameters such as metal source, reaction temperature, and solvent, two different MOFs and one ID-coordination polymer denoted as CAU-43 (1), In-MIL-53-FcDC_a (2), and InFcDC (3) were obtained. Furthermore, thermal treatment of CAU-43 (1) at 190 degrees C under vacuum yielded a new polymorph of 2, In-MIL-53-FcDC_b (4). Both MOFs 2 and 4 crystallize in a MIL-53 type structure, but in different space groups C2/m for 2 and P (1) over bar for 4. The structures of the four title compounds were determined by single-crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), or a combination of three-dimensional electron diffraction measurements (3D ED) and PXRD. N-2 sorption experiments of 1, 2, and 4 showed specific surface areas of 355 m(2) g(-)(1), 110 m(2) g(-1), and 140 m(2) g(-)(1), respectively. Furthermore, the electronic properties of the title compounds were characterized via Mossbauer and EPR spectroscopy. All Mossbauer spectra showed the characteristic doublet, proving the persistence of the ferrocene moiety. In the cases of 1, 3, and 4, appreciable impurities of ferrocenium ions could be detected by electron paramagnetic resonance spectroscopy. Cyclovoltammetric experiments were performed to demonstrate the accessible redox activity of the linker molecule of the title compounds. A redox process of FcDC(2-) with oxidation (between 0.86 and 0.97 V) and reduction wave (between 0.69 and 0.80 V) was observed.
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| 2. |
- Blunk, Inga, et al.
(author)
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Genomic imprinting analyses identify maternal effects as a cause of phenotypic variability in type 1 diabetes and rheumatoid arthritis
- 2020
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Journal article (peer-reviewed)abstract
- Imprinted genes, giving rise to parent-of-origin effects (POEs), have been hypothesised to affect type 1 diabetes (T1D) and rheumatoid arthritis (RA). However, maternal effects may also play a role. By using a mixed model that is able to simultaneously consider all kinds of POEs, the importance of POEs for the development of T1D and RA was investigated in a variance components analysis. The analysis was based on Swedish population-scale pedigree data. With P = 0.18 (T1D) and P = 0.26 (RA) imprinting variances were not significant. Explaining up to 19.00% (± 2.00%) and 15.00% (± 6.00%) of the phenotypic variance, the maternal environmental variance was significant for T1D (P = 1.60 × 10−24) and for RA (P = 0.02). For the first time, the existence of maternal genetic effects on RA was indicated, contributing up to 16.00% (± 3.00%) of the total variance. Environmental factors such as the social economic index, the number of offspring, birth year as well as their interactions with sex showed large effects.
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| 3. |
- Halis, Seida, et al.
(author)
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Dihydroxybenzoquinone as Linker for the Synthesis of Permanently Porous Aluminum Metal-Organic Frameworks
- 2016
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In: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 55:15, s. 7425-7431
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Journal article (peer-reviewed)abstract
- Two new dihydroxybenzoquinone-based metal-organic frameworks, ((CH3)(2)NH2)(3)[Al-4(L1)(3)(L1(center dot))(3)]center dot 3DMF (1, denoted CAU - 20) and ((CH3)(2)NH2)(3)[Al-4(L2)(3)(L2 center dot)(3)]center dot 9DMF (2, denoted CAU-20-Cl-2), were synthesized at 120 degrees C in PAU using 2,5-dihydroxy-p-benzoquinone ((C6H2(OH)(2)(O)(2)), H(2)L1) and 2,5-dichloro-3,6-dihydroxy-p-benzoquinone ((C6Cl2(OH)(2)(O)(2)), H(2)L2), respectively. Compared to other Al-MOFs, which contain carboxylate or phosphonate groups that connect the metal sites, in 1 and 2 the Al3+ are coordinated by oxido groups. The metal ions are octahedrally surrounded by oxygen atoms Of the deprotonated linker molecules to generate honeycomb layers with a metal to linker ratio of Al: L1/L2 = 2:3. The layers contain L1(2-) and L2(2-) ions as well as linker radical ions L1(center dot 3-) and L2(center dot 3-) in a molar ratio of 1 to 1. The presence of radical ions was confirmed by EPR and UV-vis-spectroscopic Measurements, and the composition was determined from a combination of PXRD, H-1, NMR, TG, and elemental analyses. Charge balance is accomplished through intercalation of (CH3)(2)NH2+ ions which are formed by partial hydrolysis of DMF. In the structures of 1 and 2 the eclipsed layers are AA and ABAB stacked, respectively, and one-dimensional hexagonal channels with diameters of ca. 9 and 6 angstrom are formed. Both compounds exhibit permanent porosity and have specific surface areas of 1440 and 1430 m(2) g(-1), respectively.
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| 4. |
- Krüger, Martin, et al.
(author)
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Effect of partial linker fluorination and linker extension on structure and properties of the Al-MOF CAU-10
- 2017
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In: Microporous and Mesoporous Materials. - : Elsevier BV. - 1387-1811 .- 1873-3093. ; 249, s. 128-136
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Journal article (peer-reviewed)abstract
- The systematic investigation of the solvothermal system Al3+/5-fluoroisophthalic acid (H(2)mBDC-5F)/isophthalic acid (H(2)mBDC)/DMF/H2O through a mixed-linker approach led to new mixed-linker CAU-10 derivatives containing 11, 28 and 44% of fluorinated linker molecules (denoted as CAU-10-H/F-11, CAU-10-H/F-28 and CAU-10-H/F-44, respectively), as determined by NMR spectroscopy. The crystal structure of CAU-10-H/F-28 was determined using the Rietveld method (space group 14(1)md, a = b = 21.3075(5), c = 10.7101(3) angstrom). The structure is built up by helical chains composed of cis corner-sharing AlO6 polyhedra. Each of these helices is interconnected to four adjacent helices with alternating rotational orientation through the carboxylate groups of mBDC(2-) linker molecules. Thus, accessible, square-shaped channels are formed. Sorption measurements revealed a high dependency of the adsorbed amount of gas on the degree of fluorination. With increasing fluorination, the total uptake decreases in N-2, H-2 and H2O sorption experiments and the hydrophobic character of the pores increases. In addition, an extended CAU-10 derivative, CAU-10-HTATB, was discovered using the tricarboxylic acid 4,4',4-s-triazine-2,4,6-triyl-tribenzoic acid (H(3)TATB) during the high-throughput investigation of the system Al3+/H(3)TATB/DMF/H2O. This new MOF, which was denoted CAU-10-HTATB, was thoroughly characterized using IR spectroscopy, thermogravimetric and elemental analysis, temperature dependent powder X-ray diffraction (PXRD) and sorption measurements. Although the compound is thermally stable up to 400 degrees C according to temperature-dependent PXRD measurements, it is not porous towards N2 molecules. The structure of CAU-10-HTATB could be also refined from PXRD data using the Rietveld method (space group l4(1)/a, a = b = 36.438 (1), c = 10.9373 (9) angstrom).
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| 5. |
- Krüger, Martin, et al.
(author)
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Polymorphous Al-MOFs Based on V-Shaped Linker Molecules : Synthesis, Properties, and in Situ Investigation of Their Crystallization
- 2017
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In: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 56:10, s. 5851-5862
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Journal article (peer-reviewed)abstract
- The in situ and systematic high-throughput investigation of the system Al3+/4,4'-benzophenonedicarboxylic acid (H2BPDC)/DMF/H2O in the presence of various additives was carried out, and a new Al-MOF of composition [Al(OH)(BPDC)], denoted as CAU-21-BPDC, was obtained. Its crystal structure was determined from single-crystal X-ray diffraction data (space group I422, a = b = 17.2528(7) angstrom, c = 23.864(1) angstrom). The structure is built up by octanuclear rings of cis corner-sharing AlO6 polyhedra forming the inorganic building unit (IBU). These {Al8O8} IBUs are arranged in a bcu packing and connected via BPDC2(-) ions in a way that each IBU is linked via two linker molecules to each of the eight adjacent IBUs. Thus, accessible, one-dimensional modulated pores with a diameter between 3.6 and 6.5 angstrom are formed. In addition, tetrahedral cavities are formed by the BPDC2(-) linker molecules. The framework of CAU-21-BPDC is polymorphous with that of CAU-8-BPDC, which contains one-dimensional chains of trans corner-sharing AlO6 polyhedra connected by BPDC2(-) ions. Replacing H2BPDC by 4,4'-oxydibenzoic acid (H2ODB), which contains an oxygen atom between the phenyl rings instead of a keto group, leads to the synthesis of Al-MOFs isoreticular with CAU-8-BPDC and CAU-21-BPDC. In addition, a coordination polymer, [Al(HODB)2(OH)], was discovered and structurally characterized. The structure of CAU-8-ODB was refined from powder X-ray diffraction data, while a Pawley refinement was carried out for CAU-21-ODB to determine the lattice parameters and confirm phase purity. The structure of CAU-21-ODB was confirmed using density functional theory (DFT) calculations. A thorough characterization shows that the CAU-8 and CAU-21-type structures are stable up to 350 and 300 degrees C in air, respectively, almost independent of the linker molecules incorporated. The former MOFs are porous toward N-2 and CO2, while the latter only adsorb CO2.
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| 6. |
- Leubner, Sebastian, et al.
(author)
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Synthesis and Exfoliation of a New Layered Mesoporous Zr-MOF Comprising Hexa- and Dodecanuclear Clusters as Well as a Small Organic Linker Molecule
- 2020
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In: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 142:37, s. 15995-16000
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Journal article (peer-reviewed)abstract
- A new layered mesoporous Zr-MOF of composition [Zr30O20(OH)26(OAc)18L18] was synthesized by employing 5-acetamidoisophthalic acid (H2L) using acetic acid as the solvent. The new MOF, denoted as CAU-45, exhibits a honeycomb structure of stacked layers which comprise both hexa- and dodecanucelar zirconium clusters. Its structure was solved from submicrometer-sized crystals by continuous rotation electron diffraction (cRED). Liquid phase exfoliation and size selection were successfully performed on the material.
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| 7. |
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| 8. |
- Melzer, Nina, et al.
(author)
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Investigating associations between milk metabolite profiles and milk traits of Holstein cows
- 2013
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In: Journal of Dairy Science. - New York, USA : Elsevier. - 0022-0302 .- 1525-3198. ; 96:3, s. 1521-34
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Journal article (peer-reviewed)abstract
- In the field of dairy cattle research, it is of great interest to improve the detection and prevention of diseases (e.g., mastitis and ketosis) and monitor specific traits related to the state of health and management. During the standard milk performance test, traditional milk traits are monitored, and quality and quantity are screened. In addition to the standard test, it is also now possible to analyze milk metabolites in a high-throughput manner and to consider them in connection with milk traits to identify functionally important metabolites that can also serve as biomarker candidates. We present a study in which 190 milk metabolites and 14 milk traits of 1,305 Holstein cows on 18 commercial farms were investigated to characterize interrelations of milk metabolites between each other, to milk traits from the milk standard performance test, and to influencing factors such as farm and sire effect (half-sib structure). The effect of influencing factors (e.g., farm) varied among metabolites and traditional milk traits. The investigations of associations between metabolites and milk traits revealed groups of metabolites that show, for example, positive correlations to protein and casein, and negative correlations to lactose and pH. On the other hand, groups of metabolites jointly associated with the investigated milk traits can be identified and functionally discussed. To enable a multivariate investigation, 2 machine learning methods were applied to detect important metabolites that are highly correlated with the investigated traditional milk traits. For somatic cell score, uracil, lactic acid, and 9 other important metabolites were detected. Lactic acid has already been proposed as a biomarker candidate for mastitis in the recent literature. In conclusion, we found sets of metabolites eligible to predict milk traits, enabling the analysis of milk traits from a metabolic perspective and discussion of the possible functional background for some of the detected associations.
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| 9. |
- Rabe, Timo, et al.
(author)
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Influence of the substitution pattern of four naphthalenedicarboxylic acids on the structures and properties of group 13 metal-organic frameworks and coordination polymers
- 2020
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In: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; 49:15, s. 4861-4868
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Journal article (peer-reviewed)abstract
- Metal-organic frameworks containing Ga3+ ions and four differently substituted naphthalenedicarboxylates (ndc(2-)) have been synthesized and characterized. The Ga3+ ions are six-fold coordinated by oxygen atoms in all title compounds, but two different inorganic building units, i.e. trans corner-sharing and cis,trans edge-sharing octahedra are observed. Crystal structures were validated by Rietveld refinements against powder X-ray diffraction data. [Ga(OH)(1,4-ndc)]2H(2)O crystallizes in a non-breathing MIL-53 type structure with two different pore sizes (5.5 x 5.5 angstrom and 9 x 9 angstrom). It is non-porous with respect to nitrogen but has a water adsorption capacity of about 155 mg g(-1) and a thermal stability of up to 240 degrees C. The dense compound [Ga(OH)(1,8-ndc)] crystallizes in a new layered structure motif, which is related to the crystal structure of MIL-122 ([Al(OH)((O2C)(4)C6H2)]). The third and fourth compounds [Ga-2(OH)(4)(2,3-ndc)]H2O and [Ga(OH)(2,6-ndc)]H2O are isoreticular to CAU-15 ([Al-2(OH)(4)(2,3-bdc)]H2O) and MIL-69 ([Al(OH)(2,6-ndc)]H2O), respectively. The last two compounds are non-porous toward nitrogen but reversible dehydration was demonstrated. For comparison, the two new compounds [Al(OH)(1,8-ndc)] and [Al-2(OH)(4)(2,3-ndc)]H2O, which are isostructural to the newly described gallium compounds, were also synthesized and fully characterized. The Al-containing coordination polymers exhibit higher temperature stabilities compared to their isostructural Ga compounds.
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| 10. |
- Rabe, Timo, et al.
(author)
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Isoreticular Chemistry of Group 13 Metal-Organic Framework Compounds Based on V-Shaped Linker Molecules : Exceptions to the Rule?
- 2021
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In: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 60:12, s. 8861-8869
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Journal article (peer-reviewed)abstract
- Following the concept of isoreticular chemistry, we carried out a systematic study on Ga-containing metal–organic frameworks (MOFs) using six V-shaped linker molecules of differing sizes, geometries, and additional functional groups. The linkers included three isophthalic acid derivatives (m-H2BDC-R, R = CH3, OCH3, NHCOCH3), thiophene-2,5-dicarboxylic acid (H2TDC), and two 4,4′-sulfonyldibenzoic acid derivatives (H2SDBA, DPSTA). The crystal structures of seven compounds were elucidated by a combination of model building, single-crystal X-ray diffraction (SCXRD), three-dimensional electron diffraction (3D ED), and Rietveld refinements against powder X-ray diffraction (PXRD) data. Four new Ga-MOFs that are isoreticular with their aluminum counterparts, i.e. Ga-CAU-10-R (Ga(OH)(m-BDC-R); R = OCH3, NHCOCH3), Ga-CAU-11 (Ga(OH)(SDBA)), and Ga-CAU-11-COOH (Ga(OH)(H2DPSTC)), were obtained. For the first time large single crystals of a MOF crystallizing in the CAU-10 structure type could be isolated, i.e. Ga-CAU-10-OCH3, which permitted a detailed structural characterization. In addition, the use of 5-methylisophthalic acid and thiophene-2,5-dicarboxylic acid resulted in two new Ga-MOFs denoted Ga-CAU-49 and Ga-CAU-51, respectively, which are not isostructural with any known Al-MOF. The crystal structure of Ga-CAU-49 ([Ga4(m-HBDC-CH3)2(m-BDC-CH3)3(OH)4(H2O)]) contains an unprecedented rod-shaped inorganic building unit (IBU) of the formula ∞1{Ga16(OH)18O60}, composed of corner-sharing GaO5 and GaO6 polyhedra. In Ga-CAU-51 ([Ga(OH)(C5H2O2S)]) chains of alternating cis and trans corner-sharing GaO6 polyhedra form the IBU. A detailed characterization of the title compounds was carried out, including nitrogen gas and water vapor sorption measurements. Ga-CAU-11 was the only compound exhibiting porosity toward nitrogen with a type I isotherm, a specific surface area of aS,BET = 210 m2/g, and a micropore volume of Vmic = 0.09 cm3/g. The new MOF Ga-CAU-51 exhibits exceptional water sorption properties with a reversible S-shaped isotherm and a high uptake around p/p0 = 0.38 of mads = 370 mg/g.
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