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2021 Volume 40 Issue 2
2021, 40(2): 149-159
doi: 10.14102/j.cnki.0254–5861.2011–2874
Abstract:
Two phase transition materials [iPrQ]2MnBr4 (1, iPrQ = N-isopropyl-quinuclidinium) and [iPrQ]2MnCl4 (2) were synthesized and characterized. Dielectric measurements and differential scanning calorimetry showed that the two compounds underwent reversible phase transitions at ca. –47 and –37 ℃, respectively. Variable-temperature single-crystal X-ray diffraction suggested that the two compounds underwent the same phase transitions from space group C2/c to Cc but at different temperature. The variable crystal structures indicated that the structural phase transitions of the compound were ascribed to the torsional movement of quinuclidine ring and the disappearance of the c-slide plane. The second harmonic generation (SHG) response further proved this structural phase transition. Fluorescence tests showed that the two compounds have strong fluorescence. The strong variations in dielectric anomalies make compounds 1 and 2 suitable for promising switchable dielectric materials.
Two phase transition materials [iPrQ]2MnBr4 (1, iPrQ = N-isopropyl-quinuclidinium) and [iPrQ]2MnCl4 (2) were synthesized and characterized. Dielectric measurements and differential scanning calorimetry showed that the two compounds underwent reversible phase transitions at ca. –47 and –37 ℃, respectively. Variable-temperature single-crystal X-ray diffraction suggested that the two compounds underwent the same phase transitions from space group C2/c to Cc but at different temperature. The variable crystal structures indicated that the structural phase transitions of the compound were ascribed to the torsional movement of quinuclidine ring and the disappearance of the c-slide plane. The second harmonic generation (SHG) response further proved this structural phase transition. Fluorescence tests showed that the two compounds have strong fluorescence. The strong variations in dielectric anomalies make compounds 1 and 2 suitable for promising switchable dielectric materials.
2021, 40(2): 160-168
doi: 10.14102/j.cnki.0254–5861.2011–2846
Abstract:
To search for an alternative for Nd2Fe14B, we have studied the electronic structures of R2M14B compounds, where R stands for rare-earth element and M for Mn, Fe, Co and Ni. By density functional theory (DFT), we discuss the atomic coordination environment and partial density of states (PDOS) in detail, with the emphasis on the interaction between the six kinds of M sites and the R atoms. We systemically calculated the electronic structures of sixty R2M14B compounds to provide systematic and reliable results for explaining the origination of magnetism, which is important for further development of Nd2Fe14B based magnet materials.
To search for an alternative for Nd2Fe14B, we have studied the electronic structures of R2M14B compounds, where R stands for rare-earth element and M for Mn, Fe, Co and Ni. By density functional theory (DFT), we discuss the atomic coordination environment and partial density of states (PDOS) in detail, with the emphasis on the interaction between the six kinds of M sites and the R atoms. We systemically calculated the electronic structures of sixty R2M14B compounds to provide systematic and reliable results for explaining the origination of magnetism, which is important for further development of Nd2Fe14B based magnet materials.
2021, 40(2): 169-174
doi: 10.14102/j.cnki.0254–5861.2011–2784
Abstract:
A novel metal-organic framework [Co(BTTA)(H2O)2]n (FJI-H24) has been prepared from H2BTTA ligand and CoCl2, and its structure was determined by single-crystal X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared spectroscopy. It has relatively narrow pores and high density of open metal ions and free Lewis base sites. Gas adsorption tests demonstrate that FJI-H24 has moderate CO2 (34.0 cm3·g–1) and C2H2 (53.0 cm3·g–1) adsorption capacity, but displays high selectivity of CO2/N2 (87) and C2H2/CH4 (66) under ambient conditions (298 K, 1 atm), which may be attributed to its relatively narrow pores and polar environment. This work will provide a potential strategy for preparing practical porous metal-organic frameworks for gas adsorption and purification.
A novel metal-organic framework [Co(BTTA)(H2O)2]n (FJI-H24) has been prepared from H2BTTA ligand and CoCl2, and its structure was determined by single-crystal X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared spectroscopy. It has relatively narrow pores and high density of open metal ions and free Lewis base sites. Gas adsorption tests demonstrate that FJI-H24 has moderate CO2 (34.0 cm3·g–1) and C2H2 (53.0 cm3·g–1) adsorption capacity, but displays high selectivity of CO2/N2 (87) and C2H2/CH4 (66) under ambient conditions (298 K, 1 atm), which may be attributed to its relatively narrow pores and polar environment. This work will provide a potential strategy for preparing practical porous metal-organic frameworks for gas adsorption and purification.
2021, 40(2): 175-181
doi: 10.14102/j.cnki.0254–5861.2011–2788
Abstract:
Treatment of bis(diphenylphosphino)methane (dppm) and 2-(diphenylphosphanyl)pyridine (dpppy) with Cu(CH3CN)4BF4 afforded a dinuclear Cu(I) complex [Cu2(dpppy)2(dppm)(CH3CN)](BF4)2·3CH2Cl2 (1). Complex 1 was structurally characterized by X-ray single-crystal analysis and its photophysical properties were studied in detail. It crystallizes in triclinic space group P\begin{document}$ \overline 1 $\end{document}
Treatment of bis(diphenylphosphino)methane (dppm) and 2-(diphenylphosphanyl)pyridine (dpppy) with Cu(CH3CN)4BF4 afforded a dinuclear Cu(I) complex [Cu2(dpppy)2(dppm)(CH3CN)](BF4)2·3CH2Cl2 (1). Complex 1 was structurally characterized by X-ray single-crystal analysis and its photophysical properties were studied in detail. It crystallizes in triclinic space group P
2021, 40(2): 182-186
doi: 10.14102/j.cnki.0254–5861.2011–2805
Abstract:
Under solvothermal conditions with the mixed solvents of C2H5OH and H2O, a new heterometallic lanthanide-titanium-organic compound, [TbTi(μ3-O)(L3)(H2O)4]·H3O (1, H2L = diphenylglycolic acid), has been synthesized. Compound 1 exhibits a 3D supramolecular framework by incorporating the tetra-nuclear [Tb2Ti2(μ3-O)2] unit and L2- ligand. Compound 1 shows intense green luminescence. Furthermore, the PXRD, TGA and IR spectra were also studied.
Under solvothermal conditions with the mixed solvents of C2H5OH and H2O, a new heterometallic lanthanide-titanium-organic compound, [TbTi(μ3-O)(L3)(H2O)4]·H3O (1, H2L = diphenylglycolic acid), has been synthesized. Compound 1 exhibits a 3D supramolecular framework by incorporating the tetra-nuclear [Tb2Ti2(μ3-O)2] unit and L2- ligand. Compound 1 shows intense green luminescence. Furthermore, the PXRD, TGA and IR spectra were also studied.
2021, 40(2): 187-192
doi: 10.14102/j.cnki.0254–5861.2011–2793
Abstract:
One cadmium(Ⅱ) coordination polymer [Cd(1, 4-NDC)(PPIM)2]n (1, 1, 4-H2NDC = 1, 4-naphthalenedicarboxylic acid, PPIM = 2-propylimidazole), has been synthesized under hydrothermal conditions and structurally characterized by elemental analysis, TGA and X-ray single-crystal diffraction. Complex 1 crystallizes in monoclinic with space group P21/n, a = 8.8292(2), b = 16.6936(4), c = 16.7869(4) Å, β = 99.701(2)°, V = 2438.86(10) Å3, Z = 4, Dc = 1.489 Mg/m3, F(000) = 1112, μ = 0.932 mm–1, S = 1.076, the final R = 0.0360 and wR = 0.0850. In 1, the 1, 4-NDC ligand bridges the Cd(Ⅱ) to form a 1D infinite chain, which are connected through N–H···O hydrogen bond to form a 2D layer then to an overall 3D supramolecular structure. The time-resolved measurements indicate that 1 shows highly prolonged phosphorescent lifetime about 452 times in comparison with that of pristine PPIM ligand. Single-crystal analysis and theory calculations indicate that strong coordination bonds and complete separation of HOMOs and LUMOs in the rigid matrix of 1 promote the long-last phosphorescence emission.
One cadmium(Ⅱ) coordination polymer [Cd(1, 4-NDC)(PPIM)2]n (1, 1, 4-H2NDC = 1, 4-naphthalenedicarboxylic acid, PPIM = 2-propylimidazole), has been synthesized under hydrothermal conditions and structurally characterized by elemental analysis, TGA and X-ray single-crystal diffraction. Complex 1 crystallizes in monoclinic with space group P21/n, a = 8.8292(2), b = 16.6936(4), c = 16.7869(4) Å, β = 99.701(2)°, V = 2438.86(10) Å3, Z = 4, Dc = 1.489 Mg/m3, F(000) = 1112, μ = 0.932 mm–1, S = 1.076, the final R = 0.0360 and wR = 0.0850. In 1, the 1, 4-NDC ligand bridges the Cd(Ⅱ) to form a 1D infinite chain, which are connected through N–H···O hydrogen bond to form a 2D layer then to an overall 3D supramolecular structure. The time-resolved measurements indicate that 1 shows highly prolonged phosphorescent lifetime about 452 times in comparison with that of pristine PPIM ligand. Single-crystal analysis and theory calculations indicate that strong coordination bonds and complete separation of HOMOs and LUMOs in the rigid matrix of 1 promote the long-last phosphorescence emission.
2021, 40(2): 193-198
doi: 10.14102/j.cnki.0254–5861.2011–2794
Abstract:
A very stable CdⅡ-organic framework, {[Cd3(Tipe)1.5(bpodc)2Cl2]·(H2O)2}n (compound 1, Tipe = 1, 1, 2, 2-tetrakis(4-(imidazol-1-yl)phenyl)ethene, bpodc = benzophenone-4, 4-dicarboxylic acid), has been successfully synthesized under hydrothermal conditions. Compound 1 crystallizes in the triclinic system, space group P\begin{document}$ \overline 1 $\end{document}
A very stable CdⅡ-organic framework, {[Cd3(Tipe)1.5(bpodc)2Cl2]·(H2O)2}n (compound 1, Tipe = 1, 1, 2, 2-tetrakis(4-(imidazol-1-yl)phenyl)ethene, bpodc = benzophenone-4, 4-dicarboxylic acid), has been successfully synthesized under hydrothermal conditions. Compound 1 crystallizes in the triclinic system, space group P
2021, 40(2): 199-206
doi: 10.14102/j.cnki.0254–5861.2011–2796
Abstract:
So far, the synthesis of chiral framework with achiral organic ligand still faces great challenge. Herein, three new coordinated complexes [Zn(btca)Cl]·DMA·N(CH3)2 (1), [Zn(btca)(Ac-)]·N(CH3)2 (2) and [Zn(btca)]·H2O (3) (DMA = N, N-dimethylacetamide, btca = benzotriazole-5-carboxylate acid) were synthesized via different methods. Single-crystal X-ray diffraction analysis revealed that compounds 1 and 2 were isostructural and showed achiral layer network with fes topology, and 3 presented a chiral three-dimensional framework with eta topology. The result of this work has demonstrated that urothermal synthesis will be promising means of constructing chiral framework with achiral building block. Compound 3 also displayed an excellent property of iodine uptake.
So far, the synthesis of chiral framework with achiral organic ligand still faces great challenge. Herein, three new coordinated complexes [Zn(btca)Cl]·DMA·N(CH3)2 (1), [Zn(btca)(Ac-)]·N(CH3)2 (2) and [Zn(btca)]·H2O (3) (DMA = N, N-dimethylacetamide, btca = benzotriazole-5-carboxylate acid) were synthesized via different methods. Single-crystal X-ray diffraction analysis revealed that compounds 1 and 2 were isostructural and showed achiral layer network with fes topology, and 3 presented a chiral three-dimensional framework with eta topology. The result of this work has demonstrated that urothermal synthesis will be promising means of constructing chiral framework with achiral building block. Compound 3 also displayed an excellent property of iodine uptake.
2021, 40(2): 207-216
doi: 10.14102/j.cnki.0254-5861.2011-2811
Abstract:
To investigate how the electronic effect of ligand at donor site influences electronic communication or metal-to-metal charge transfer (MMCT) properties in similar mixed-valence (MV) complexes, a series of binuclear organometallic complexes, MeCp(dppe)RuCNFeCl3 (1), MeCp(PPh3)2RuCNFeCl3 (2), Cp*(dppe)FeCNFeCl3 (3), Cp*(dppe)RuCNFeCl3 (4) and Cp*(PPh3)2RuCNFeCl3 (5), have been synthesized and characterized. The electronic absorptions of these complexes show the presence of MMCT properties between RuⅡ or FeⅡ and FeⅢ ions, strongly supported by the theoretical calculations. With increasing electron-donating ability of ligands (PPh3 > dppe, Cp* > MeCp) at donor site, the MMCT absorption bands are red-shifted, which expresses in the sequence of absorption bands with 1 (500 nm), 4 (536 nm), 2 (542 nm), 5 (580 nm) from high-energy to low-energy. Meanwhile, the MMCT absorption energy of 4 (536 nm) is larger than that of 3 (760 nm) due to the stronger electron-donating ability of FeⅡ than RuⅡ. Furthermore, these complexes belong to the Class Ⅱ systems according to the Robin and Day's classification.
To investigate how the electronic effect of ligand at donor site influences electronic communication or metal-to-metal charge transfer (MMCT) properties in similar mixed-valence (MV) complexes, a series of binuclear organometallic complexes, MeCp(dppe)RuCNFeCl3 (1), MeCp(PPh3)2RuCNFeCl3 (2), Cp*(dppe)FeCNFeCl3 (3), Cp*(dppe)RuCNFeCl3 (4) and Cp*(PPh3)2RuCNFeCl3 (5), have been synthesized and characterized. The electronic absorptions of these complexes show the presence of MMCT properties between RuⅡ or FeⅡ and FeⅢ ions, strongly supported by the theoretical calculations. With increasing electron-donating ability of ligands (PPh3 > dppe, Cp* > MeCp) at donor site, the MMCT absorption bands are red-shifted, which expresses in the sequence of absorption bands with 1 (500 nm), 4 (536 nm), 2 (542 nm), 5 (580 nm) from high-energy to low-energy. Meanwhile, the MMCT absorption energy of 4 (536 nm) is larger than that of 3 (760 nm) due to the stronger electron-donating ability of FeⅡ than RuⅡ. Furthermore, these complexes belong to the Class Ⅱ systems according to the Robin and Day's classification.
2021, 40(2): 217-224
doi: 10.14102/j.cnki.0254-5861.2011-2809
Abstract:
A new manganese coordination polymer (CP) has been synthesized under hydrothermal conditions. It's formula is {Mn2(Oaobtc)(bpe)(H2O)4]}n, where H4Oobtc represents oxide azobenzene 2, 2΄, 3, 3΄-tetracarboxyl acid, and bpe is 1,2-bis(4-pyridine) ethylene. It was characterized by elemental analysis, infrared spectrum and X-ray single-crystal diffraction. The coordination polymer crystallizes in the monoclinic system, space group P21/c. The central ion was coordinated with H4Oobtc ligands using bridging model, and carboxylic group connects two adjacent Mn(Ⅱ) ions into dimer units. The oxygen from carboxylates connect these dimer units into a one-dimensional (1D) chain, and N atoms from the bpe further expanded them into three-dimensional (3D) supramolecular edifice, eventually. Variable-temperature magnetic measurements of CP 1 indicate the presence of weak antiferromagnetic exchange between two nearest Mn(Ⅱ) ions with J = –0.367 cm−1.
A new manganese coordination polymer (CP) has been synthesized under hydrothermal conditions. It's formula is {Mn2(Oaobtc)(bpe)(H2O)4]}n, where H4Oobtc represents oxide azobenzene 2, 2΄, 3, 3΄-tetracarboxyl acid, and bpe is 1,2-bis(4-pyridine) ethylene. It was characterized by elemental analysis, infrared spectrum and X-ray single-crystal diffraction. The coordination polymer crystallizes in the monoclinic system, space group P21/c. The central ion was coordinated with H4Oobtc ligands using bridging model, and carboxylic group connects two adjacent Mn(Ⅱ) ions into dimer units. The oxygen from carboxylates connect these dimer units into a one-dimensional (1D) chain, and N atoms from the bpe further expanded them into three-dimensional (3D) supramolecular edifice, eventually. Variable-temperature magnetic measurements of CP 1 indicate the presence of weak antiferromagnetic exchange between two nearest Mn(Ⅱ) ions with J = –0.367 cm−1.
2021, 40(2): 225-232
doi: 10.14102/j.cnki.0254-5861.2011-2817
Abstract:
The electrosynthesis of H2O2 as an environmentally friendly green process has attracted great attention due to the importance of H2O2 in industry and human lives. In this work, a new strategy was proposed to improve the electrical conductivity and H2O2 selectivity of transition metal oxides catalysts. F−C (F doped carbon) was coupled with Ta2O5 by calcining polyvinylidene fluoride (PVDF) as the carbon source using one step method. The Ta2O5/F−C composite catalysts show an excellent H2O2 selectivity of more than 80% as well as high reactivity at 2.52 mA/cm2, which is greatly enhanced compared to the counterparts of F−C (selectivity of 59%) and Ta2O5-800 (current density of 0.85 mA/cm2) in 0.1 M KOH solution. The onset potential for H2O2 production on Ta2O5/F−C composites is 0.78 V in 0.1 M KOH, which indicates a negligible overpotential. In addition, H2O2 selectivity of the catalyst can be stabilized at more than 80% after 10 hours of electrolysis in alkaline electrolyte. The high performance due to the introduction of F−C increases the conductivity of Ta2O5 and the synergistic effect between F−C and Ta2O5. This work proposed an efficient synergistic effect among F-doped C and Ta2O5 for H2O2 production.
The electrosynthesis of H2O2 as an environmentally friendly green process has attracted great attention due to the importance of H2O2 in industry and human lives. In this work, a new strategy was proposed to improve the electrical conductivity and H2O2 selectivity of transition metal oxides catalysts. F−C (F doped carbon) was coupled with Ta2O5 by calcining polyvinylidene fluoride (PVDF) as the carbon source using one step method. The Ta2O5/F−C composite catalysts show an excellent H2O2 selectivity of more than 80% as well as high reactivity at 2.52 mA/cm2, which is greatly enhanced compared to the counterparts of F−C (selectivity of 59%) and Ta2O5-800 (current density of 0.85 mA/cm2) in 0.1 M KOH solution. The onset potential for H2O2 production on Ta2O5/F−C composites is 0.78 V in 0.1 M KOH, which indicates a negligible overpotential. In addition, H2O2 selectivity of the catalyst can be stabilized at more than 80% after 10 hours of electrolysis in alkaline electrolyte. The high performance due to the introduction of F−C increases the conductivity of Ta2O5 and the synergistic effect between F−C and Ta2O5. This work proposed an efficient synergistic effect among F-doped C and Ta2O5 for H2O2 production.
2021, 40(2): 233-238
doi: 10.14102/j.cnki.0254-5861.2011-2862
Abstract:
Potassium-ion batteries (KIBs) are a promising alternative to Lithium-based energy storage systems owning to the low cost and rich abundance of potassium resources, but are facing challenges in designing low-cost hosts that can reversibly accommodate large-size K+ with fast diffusion kinetics. Herein, we report a novel 3D inorganic open framework of Ca2Nb2O7 (CNO) as an anode for KIBs. The open framework structure affords interstitial vacancies available for storing K+ and allows a facile diffusion of K+, thus resulting in excellent structural stability and fast reaction kinetics. The CNO electrode delivers a reversible specific capacity of 65.3 and 52.2 mAh/g at 5 and 10 mA/g, respectively. Moreover, CNO exhibits excellent long-term cyclability with 92.53% capacity retention over 700 cycles at 10 mA/g. This will trigger more investigations into open-framework-based materials for stable and fast KIBs.
Potassium-ion batteries (KIBs) are a promising alternative to Lithium-based energy storage systems owning to the low cost and rich abundance of potassium resources, but are facing challenges in designing low-cost hosts that can reversibly accommodate large-size K+ with fast diffusion kinetics. Herein, we report a novel 3D inorganic open framework of Ca2Nb2O7 (CNO) as an anode for KIBs. The open framework structure affords interstitial vacancies available for storing K+ and allows a facile diffusion of K+, thus resulting in excellent structural stability and fast reaction kinetics. The CNO electrode delivers a reversible specific capacity of 65.3 and 52.2 mAh/g at 5 and 10 mA/g, respectively. Moreover, CNO exhibits excellent long-term cyclability with 92.53% capacity retention over 700 cycles at 10 mA/g. This will trigger more investigations into open-framework-based materials for stable and fast KIBs.
2021, 40(2): 239-245
doi: 10.14102/j.cnki.0254-5861.2011-2818
Abstract:
The title compounds (5a and 5b) were synthesized from ursolic acid and their structures were characterized by spectroscopic methods including ESI-MS, 1H-NMR, 13C-NMR and elemental analysis. The crystal structures of compounds 5a and 5b were determined by single-crystal X-ray diffraction analysis. Compound 5a crystallizes in monoclinic system, P21 space group with a = 12.258(3), b = 10.396(2), c = 15.570(3) Å, β = 107.21(3)°, Z = 2, V = 1895.3(7) Å3, Mr = 659.90, Dc = 1.156 Mg/m3, S = 1.003, µ = 0.076 mm−1, F(000) = 716, the final R = 0.0686 and wR = 0.1430 for 1859 observed reflections (I > 2σ(I)). Compound 5b crystallizes in monoclinic system, P21 space group with a = 12.371(3), b = 10.647(2), c = 15.722(3) Å, β = 109.44(3)°, Z = 2, V = 1952.8(8) Å3, Mr = 655.93, Dc = 1.116 Mg/m3, S = 1.002, µ = 0.069 mm−1, F(000) = 716, the final R = 0.0686 and wR = 0.1882 for 2574 observed reflections (I > 2σ(I)). The preliminary cytotoxic assay indicated that compound 5b exhibited notable cytotoxic activity against MCF-7 and HeLa cells with the IC50 values of 10.71 ± 0.23 and 12.63 ± 0.31 μM, respectively.
The title compounds (5a and 5b) were synthesized from ursolic acid and their structures were characterized by spectroscopic methods including ESI-MS, 1H-NMR, 13C-NMR and elemental analysis. The crystal structures of compounds 5a and 5b were determined by single-crystal X-ray diffraction analysis. Compound 5a crystallizes in monoclinic system, P21 space group with a = 12.258(3), b = 10.396(2), c = 15.570(3) Å, β = 107.21(3)°, Z = 2, V = 1895.3(7) Å3, Mr = 659.90, Dc = 1.156 Mg/m3, S = 1.003, µ = 0.076 mm−1, F(000) = 716, the final R = 0.0686 and wR = 0.1430 for 1859 observed reflections (I > 2σ(I)). Compound 5b crystallizes in monoclinic system, P21 space group with a = 12.371(3), b = 10.647(2), c = 15.722(3) Å, β = 109.44(3)°, Z = 2, V = 1952.8(8) Å3, Mr = 655.93, Dc = 1.116 Mg/m3, S = 1.002, µ = 0.069 mm−1, F(000) = 716, the final R = 0.0686 and wR = 0.1882 for 2574 observed reflections (I > 2σ(I)). The preliminary cytotoxic assay indicated that compound 5b exhibited notable cytotoxic activity against MCF-7 and HeLa cells with the IC50 values of 10.71 ± 0.23 and 12.63 ± 0.31 μM, respectively.
2021, 40(2): 246-255
doi: 10.14102/j.cnki.0254-5861.2011-2822
Abstract:
New functional materials of metal chalcophosphates have been receiving increasing attention due to their wide structural diversity and technologically promising properties. In this work, a quaternary selenophosphate, Cs2ZnP2Se6, has been successfully prepared by the high-temperature solid state reactions with a modified reactive CsCl flux. Single-crystal X-ray diffraction analyses show that Cs2ZnP2Se6 crystallizes in triclinic space group P\begin{document}$ \overline 1 $\end{document}
New functional materials of metal chalcophosphates have been receiving increasing attention due to their wide structural diversity and technologically promising properties. In this work, a quaternary selenophosphate, Cs2ZnP2Se6, has been successfully prepared by the high-temperature solid state reactions with a modified reactive CsCl flux. Single-crystal X-ray diffraction analyses show that Cs2ZnP2Se6 crystallizes in triclinic space group P
2021, 40(2): 256-263
doi: 10.14102/j.cnki.0254-5861.2011-2851
Abstract:
A potassium silicophosphate, K2SiP4O13, has been synthesized in molten polyphosphoric acid. It crystalizes in the triclinic space group P\begin{document}$ \overline 1 $\end{document}
A potassium silicophosphate, K2SiP4O13, has been synthesized in molten polyphosphoric acid. It crystalizes in the triclinic space group P
2021, 40(2): 264-269
doi: 10.14102/j.cnki.0254-5861.2011-2816
Abstract:
A new metal chalcogenide, γ-Hg3S2Br2 (1), has been prepared by moderate-temperature solid-state reaction, and its crystal structure was determined by single-crystal X-ray diffraction analysis. Compound 1 crystallizes in space group Cmmm of orthorhombic system with a = 9.1923(18), b = 18.2262(5), c = 4.6251(7) Å, V = 774.9(3) Å3 and Z = 4. In the structure, two Hg(1), two Hg(2) and four S(1) atoms form a near square Hg4S4, and such squares are linked by Hg(3) atoms nearly linearly coordinated to two S1 atoms of two parallel Hg4S4 squares to form one-dimensional infinite Hg6S4 chains along c direction. Optical absorption spectra reveal the presence of sharp optical gap of 2.80 eV for 1. IR spectrum, TGA and electric resistivity have been investigated.
A new metal chalcogenide, γ-Hg3S2Br2 (1), has been prepared by moderate-temperature solid-state reaction, and its crystal structure was determined by single-crystal X-ray diffraction analysis. Compound 1 crystallizes in space group Cmmm of orthorhombic system with a = 9.1923(18), b = 18.2262(5), c = 4.6251(7) Å, V = 774.9(3) Å3 and Z = 4. In the structure, two Hg(1), two Hg(2) and four S(1) atoms form a near square Hg4S4, and such squares are linked by Hg(3) atoms nearly linearly coordinated to two S1 atoms of two parallel Hg4S4 squares to form one-dimensional infinite Hg6S4 chains along c direction. Optical absorption spectra reveal the presence of sharp optical gap of 2.80 eV for 1. IR spectrum, TGA and electric resistivity have been investigated.
