{"title":"基于镧系元素的 F-MOF:结构、水解稳定性、光谱和磁性能","authors":"","doi":"10.1016/j.jssc.2024.124949","DOIUrl":null,"url":null,"abstract":"<div><p>A series of five novel lanthanide-based fluorinated metal-organic frameworks (Ln-F-MOFs) have been synthesized under solvothermal conditions by the reaction of 3,3′-bis(trifluoromethyl)-[1,1′-biphenyl]-4,4′-dicarboxylic acid (<strong>H</strong><sub><strong>2</strong></sub><strong>L</strong>) and lanthanide Ln(III) ions (Ln(III)<img>La, Ce, Pr, Nd and Eu). Powder X-ray diffraction (PXRD) analysis revealed that all prepared complexes are isostructural. A single-crystal X-ray crystallographic study of one representative of the isostructural group, namely {[La<sub>2</sub>(<strong>L</strong>)<sub>3</sub>(DMF)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]}<sub>n</sub> showed, that compound crystallizes in a triclinic system with space group <em>P</em>-1. The lattice parameter values are <em>a</em> = 8.563(2) Å, <em>b</em> = 13.199(3) Å, <em>c</em> = 16.008(4) Å, <em>α</em> = 104.588(7) °, <em>β</em> = 92.904(7) ° and <em>γ</em> = 92.717(7) °, with two formula units in the unit cell. The overall structure is formed by 2D polymeric layers, which are arranged into a semi-3D supramolecular structure through hydrogen bonds and other intramolecular interactions. The study of the hydrophobic properties of the complexes showed that the complexes exhibit surface hydrophobicity with a “rose petal effect” and a contact angle of approximately 107°. However, the structures are not hydrolytically stable in the long term and the structure starts to delaminate after two days in water. This is a manifestation of the fact that the complexes do not form a 3D polymer network, it is made up of 2D layers connected only by weak non-bonding interactions. The photoluminescence properties of the Ln(III) complexes are determined by the characteristic 5<em>d</em>-4<em>f</em> or 4<em>f</em>-4<em>f</em> electron transitions for the individual lanthanide ions. The magnetic properties of Nd(III), Pr(III) and Eu(III) variants were studied. The magnetic properties of {[Pr<sub>2</sub>(<strong>L</strong>)<sub>3</sub>(DMF)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]}<sub>n</sub> are characterized by the presence of a low-lying quasi-doublet with 15.6 cm<sup>−1</sup> energy splitting, whereas Eu(III) variant is nonmagnetic at low temperatures, but the magnetic <sup>7</sup><em>F</em><sub>1</sub> state is accessible by thermal excitation. For Nd(III) complex, the X-band EPR measurements were performed. Since 1D channels with dimensions of 4.90 × 7.23 Å<sup>2</sup> are present within the structure, the adsorption of N<sub>2</sub>, CO<sub>2</sub> and H<sub>2</sub> gases was also studied.</p></div>","PeriodicalId":378,"journal":{"name":"Journal of Solid State Chemistry","volume":null,"pages":null},"PeriodicalIF":3.2000,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022459624004031/pdfft?md5=911e038cbc4e04b63f83dc333cdf5716&pid=1-s2.0-S0022459624004031-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Lanthanide-based F-MOFs: Structure, hydrolytic stability, spectral and magnetic properties\",\"authors\":\"\",\"doi\":\"10.1016/j.jssc.2024.124949\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>A series of five novel lanthanide-based fluorinated metal-organic frameworks (Ln-F-MOFs) have been synthesized under solvothermal conditions by the reaction of 3,3′-bis(trifluoromethyl)-[1,1′-biphenyl]-4,4′-dicarboxylic acid (<strong>H</strong><sub><strong>2</strong></sub><strong>L</strong>) and lanthanide Ln(III) ions (Ln(III)<img>La, Ce, Pr, Nd and Eu). Powder X-ray diffraction (PXRD) analysis revealed that all prepared complexes are isostructural. A single-crystal X-ray crystallographic study of one representative of the isostructural group, namely {[La<sub>2</sub>(<strong>L</strong>)<sub>3</sub>(DMF)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]}<sub>n</sub> showed, that compound crystallizes in a triclinic system with space group <em>P</em>-1. The lattice parameter values are <em>a</em> = 8.563(2) Å, <em>b</em> = 13.199(3) Å, <em>c</em> = 16.008(4) Å, <em>α</em> = 104.588(7) °, <em>β</em> = 92.904(7) ° and <em>γ</em> = 92.717(7) °, with two formula units in the unit cell. The overall structure is formed by 2D polymeric layers, which are arranged into a semi-3D supramolecular structure through hydrogen bonds and other intramolecular interactions. The study of the hydrophobic properties of the complexes showed that the complexes exhibit surface hydrophobicity with a “rose petal effect” and a contact angle of approximately 107°. However, the structures are not hydrolytically stable in the long term and the structure starts to delaminate after two days in water. This is a manifestation of the fact that the complexes do not form a 3D polymer network, it is made up of 2D layers connected only by weak non-bonding interactions. The photoluminescence properties of the Ln(III) complexes are determined by the characteristic 5<em>d</em>-4<em>f</em> or 4<em>f</em>-4<em>f</em> electron transitions for the individual lanthanide ions. The magnetic properties of Nd(III), Pr(III) and Eu(III) variants were studied. The magnetic properties of {[Pr<sub>2</sub>(<strong>L</strong>)<sub>3</sub>(DMF)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]}<sub>n</sub> are characterized by the presence of a low-lying quasi-doublet with 15.6 cm<sup>−1</sup> energy splitting, whereas Eu(III) variant is nonmagnetic at low temperatures, but the magnetic <sup>7</sup><em>F</em><sub>1</sub> state is accessible by thermal excitation. For Nd(III) complex, the X-band EPR measurements were performed. Since 1D channels with dimensions of 4.90 × 7.23 Å<sup>2</sup> are present within the structure, the adsorption of N<sub>2</sub>, CO<sub>2</sub> and H<sub>2</sub> gases was also studied.</p></div>\",\"PeriodicalId\":378,\"journal\":{\"name\":\"Journal of Solid State Chemistry\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.2000,\"publicationDate\":\"2024-08-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S0022459624004031/pdfft?md5=911e038cbc4e04b63f83dc333cdf5716&pid=1-s2.0-S0022459624004031-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Solid State Chemistry\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0022459624004031\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, INORGANIC & NUCLEAR\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Solid State Chemistry","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022459624004031","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
Lanthanide-based F-MOFs: Structure, hydrolytic stability, spectral and magnetic properties
A series of five novel lanthanide-based fluorinated metal-organic frameworks (Ln-F-MOFs) have been synthesized under solvothermal conditions by the reaction of 3,3′-bis(trifluoromethyl)-[1,1′-biphenyl]-4,4′-dicarboxylic acid (H2L) and lanthanide Ln(III) ions (Ln(III)La, Ce, Pr, Nd and Eu). Powder X-ray diffraction (PXRD) analysis revealed that all prepared complexes are isostructural. A single-crystal X-ray crystallographic study of one representative of the isostructural group, namely {[La2(L)3(DMF)2(H2O)2]}n showed, that compound crystallizes in a triclinic system with space group P-1. The lattice parameter values are a = 8.563(2) Å, b = 13.199(3) Å, c = 16.008(4) Å, α = 104.588(7) °, β = 92.904(7) ° and γ = 92.717(7) °, with two formula units in the unit cell. The overall structure is formed by 2D polymeric layers, which are arranged into a semi-3D supramolecular structure through hydrogen bonds and other intramolecular interactions. The study of the hydrophobic properties of the complexes showed that the complexes exhibit surface hydrophobicity with a “rose petal effect” and a contact angle of approximately 107°. However, the structures are not hydrolytically stable in the long term and the structure starts to delaminate after two days in water. This is a manifestation of the fact that the complexes do not form a 3D polymer network, it is made up of 2D layers connected only by weak non-bonding interactions. The photoluminescence properties of the Ln(III) complexes are determined by the characteristic 5d-4f or 4f-4f electron transitions for the individual lanthanide ions. The magnetic properties of Nd(III), Pr(III) and Eu(III) variants were studied. The magnetic properties of {[Pr2(L)3(DMF)2(H2O)2]}n are characterized by the presence of a low-lying quasi-doublet with 15.6 cm−1 energy splitting, whereas Eu(III) variant is nonmagnetic at low temperatures, but the magnetic 7F1 state is accessible by thermal excitation. For Nd(III) complex, the X-band EPR measurements were performed. Since 1D channels with dimensions of 4.90 × 7.23 Å2 are present within the structure, the adsorption of N2, CO2 and H2 gases was also studied.
期刊介绍:
Covering major developments in the field of solid state chemistry and related areas such as ceramics and amorphous materials, the Journal of Solid State Chemistry features studies of chemical, structural, thermodynamic, electronic, magnetic, and optical properties and processes in solids.