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ArticleTwo Low-temperature Phase Transition Compounds Based on Quinuclidine Derivatives with Fluorescence
LI Jun-Yi, CHEN Xiang, TONG Liang, DENG Si-Yu* and CHEN Li-Zhuang*
Chin. J. Struct. Chem. 2021, 40, 149-159 DOI: 10.14102/j.cnki.0254-5861.2011-2874
February 15, 2021
quinuclidine derivatives, fluorescent compounds, crystal structure, second harmonic generation (SHG), permittivity properties
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 °C, 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. -
ArticleTheoretical Studies on the Electronic Properties of R2M14B (R = Lanthanides from La to Lu; M = Mn, Fe, Co, and Ni)
RAO Shuang, LIN Chen-Sheng, HE Zhang-Zhen and CHAI Guo-Liang*
Chin. J. Struct. Chem. 2021, 40, 160-168 DOI: 10.14102/j.cnki.0254-5861.2011-2846
partial density of states, Nd2Fe14B, density functional theory, electronic structure
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. -
ArticleA Novel Co(II)-organic Framework with Multiple Active Sites for Selective Gas Adsorption
SHI Cheng-Dan, TIAN Jia-Yue, JIANG Fei-Long, CHEN Qi-Hui* and HONG Mao-Chun*
Chin. J. Struct. Chem. 2021, 40, 169-174 DOI: 10.14102/j.cnki.0254-5861.2011-2784
February 15, 2021
metal-organic frameworks, gas adsorption, gas purification, open metal ions, Lewis base sites
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. -
ArticleSynthesis, Structure and Photophysical Properties of a Dinuclear Copper(I) Complex Based on Phosphino- pyridine and Diphosphine Mixed-ligandsYU Wen-Si, HUANG Chun-Hua and HUANG Xi-He*
Chin. J. Struct. Chem. 2021, 40, 175-181 DOI: 10.14102/j.cnki.0254-5861.2011-2788
February 15, 2021
copper(I) complex, thermally activated delayed fluorescence, crystalline structure
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 with a = 13.0834(8), b = 13.5568(8), c = 21.8544(11) Å, α = 76.090(5)°, β = 80.803(5)°, γ = 64.582(6)°, V = 3391.3(3) Å3, Z = 2, Mr = 1507.42, Dc = 1.476 g/cm3, F(000) = 1532, GOOF = 1.071, the final R = 0.0700 for 9041 observed reflections with I > 2σ(I) and wR = 0.2063 for all data. The complex contains a Cu2-core structure surrounded by one dppm and two dpppy ligands in a head-to-head arrangement. In the crystalline phase, complex 1 exhibits bright bluish-green photoluminescence (λmax = 488 nm) with high quantum yield (ϕ = 0.57) at room temperature. It is still a relatively high emission quantum yield (ϕ = 0.36) in doped PMMA thin film with 20 wt% dopant of complex 1. The emission peaks of 1 in dichloromethane solution and doped PMMA (20 wt%) thin films are 510 and 494 nm, respectively, showing a very slight bathochromic shift compared to that in crystalline phase. This phenomenon might be attributed to its rigid conformation that precludes the possible distortion of copper centers in the excited state. -
ArticleLuminescent Lanthanide-titanium-organic Compound Constructed by Tetra-nuclear Ln-Ti Building Units and Diphenylglycolic AcidCHEN Zi-Bin, CHEN Bing-Ben and CHENG Jian-Wen*
Chin. J. Struct. Chem. 2021, 40, 182-186 DOI: 10.14102/j.cnki.0254-5861.2011-2805
February 15, 2021
lanthanide, titanium, cluster, luminescence
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. -
ArticleSynthesis, Structure and Highly Enhanced Phosphorescence of a Cadmium(II) Coordination Polymer Assembled with 1,4-Naphthalenedicarboxylic Acid and 2-Propylimidazole
CHANG Xin-Hong*, YANG Xiao-Gang, ZHAI Zhi-Min, CHEN Jia-Yi and LI Fei-Fei
Chin. J. Struct. Chem. 2021, 40, 187-192 DOI: 10.14102/j.cnki.0254-5861.2011-2793
February 15, 2021
coordination polymer, crystal structure, room temperature phosphorescence, theory calculations
ABSTRACT
One cadmium(II) coordination polymer [Cd(1,4-NDC)(PPIM)2]n (1, 1,4-H2NDC = 1,4-na- phthalenedicarboxylic 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. -
ArticleSynthesis, Structure and Fluorescence Property of New Cd-MOFs Based on a Tetraphenylethylene (TPE) Ligand
LIANG Yu, XU Xiu-Dian, NI Jian-Ling, LI Jun-Feng and WANG Fang-Ming*
Chin. J. Struct. Chem. 2021, 40, 193-198 DOI: 10.14102/j.cnki.0254-5861.2011-2794
February 15, 2021
tetraphenylethane, sensor, luminescent, metal-organic framework
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
, with a = 12.289(3), b = 15.951(4), c = 20.755(5) Å, α = 81.248(2)°, β = 83.905(2)°, γ = 89.452(2)°, V = 3998.2(17)
Å3, Z = 2, Mr = 1839.59, Dc = 1.528 g/cm3, μ = 0.925 mm-1, F(000) = 1844, R = 0.0508 and wR = 0.1571
for 13998 observed reflections (I > 2σ(I)). Its overall structure
is a three-dimensional stacking with a porosity of 10.1% based on a calculation by PLATON. Compound 1 shows a
blue fluorescence emission with the peak maximum of 501 nm (λex = 397 nm) by
ligand-to-ligand charge transfer of TPE chromophore. And it exhibits excellent
performance in detecting Fe3+ and Cr2O72- ions in
aqueous solutions as a multi-response sensor.
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ArticleUrothermal Syntheses of Chiral Zincic Benzotriazole-5-carboxylate Frameworks for Iodine Uptake
HUANG Zai-Chun, WANG Xiao-Fang, GOHI Bi Foua Claude Alain*, LI Yu-Feng, KANG Yao* and JIANG Zhi-Qiang*
Chin. J. Struct. Chem. 2021, 40, 199-206 DOI: 10.14102/j.cnki.0254-5861.2011-2796
February 15, 2021
urothermal synthesis, benzotriazole-5-carboxylate acid, chirality, I2 absorption
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. -
Influence of Ligand with Fine Difference at Donor Site on MMCT Property in Binuclear Mixed Valence ComplexesLI Su-Hua, YANG Yu-Ying, ZHANG Yu-Xiao, WU Xin-Tao and SHENG Tian-Lu*
Chin. J. Struct. Chem. 2021, 40, 207-216 DOI: 10.14102/j.cnki.0254-5861.2011-2811
February 15, 2021
metal-to-metal charge transfer (MMCT), mixed-valence complexes, Class II
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. -
ArticleA New Manganese Coordination Polymer Based on Azobenzene Tetracarboxylate and Auxiliary Pyridine Ligand: Synthesis, Crystal Structure and Magnetic Property
FENG Xun*, SHANG Ya-Pei, WANG Li-Ya, HONG Man-Zhou, FANG Hai-Peng, ZHAO Xin and LI Zhong-Jun
Chin. J. Struct. Chem. 2021, 40, 217-224 DOI: 10.14102/j.cnki.0254-5861.2011-2809
February 15, 2021
acetate bridging, manganese(II), X-ray crystal structure, oxidation azoxybenzene-2,2΄,3,3΄-tetra- carboxyl acid, antiferromagnetic interaction
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. -
ArticleSynergistic Effect of Ta2O5/F-C Composites for Effective Electrosynthesis of Hydrogen Peroxide from O2 Reduction
WANG Ke, PANG Yong-Yu, XIE Huan, SUN Yuan and CHAI Guo-Liang*
Chin. J. Struct. Chem. 2021, 40, 225-232 DOI: 10.14102/j.cnki.0254-5861.2011-2817
February 15, 2021
Ta2O5/F-C, oxygen reduction reaction, hydrogen peroxide
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. -
ArticleCa2Nb2O7 as a Novel Open-framework Anode Material for Potassium-ion Batteries
YANG Xin, WANG Zheng-Dong, FU Yu-Ru, LIU Qin* and XIAO Gao*
Chin. J. Struct. Chem. 2021, 40, 233-238 DOI: 10.14102/j.cnki.0254-5861.2011-2817
February 15, 2021
potassium-ion batteries, inorganic-open-framework, long lifespan, kinetics
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. -
ArticleSynthesis, Crystal Structures and Cytotoxic Activities of Two New Pyrimidine Derivatives of Ursolic Acid
WANG Wen-Yan, LI A-Liang, LIU Qing-Song, SUN Yue and GU Wen*
Chin. J. Struct. Chem. 2021, 40, 239-245 DOI: 10.14102/j.cnki.0254-5861.2011-2818
February 15, 2021
ursolic acid, pyrimidine, crystal structure, cytotoxic activity
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, b = 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, b = 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. -
ArticleQuaternary Selenophosphate Cs2ZnP2Se6 Featuring Unique One-dimensional Chains and Exhibiting Remarkable Photo-electrochemical Response
LI Meng-Yue, XIE Xiu-Yuan, WU Xin-Tao, LI Xiao-Fang* and LIN Hua*
Chin. J. Struct. Chem. 2021, 40, 246-255 DOI: 10.14102/j.cnki.0254-5861.2011-2822
February 15, 2021
selenophosphate, zinc, one-dimensional chain, photo-electrochemistry, semiconductor
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 -
ArticleSynthesis, Structure and Characterization of a New Silicophosphate, K2SiP4O13, with a Six-fold Coordinated Si
SUN Tong-Qing*, WANG Qian-Qian, KONG Yong-Fa and XU Jing-Jun
Chin. J. Struct. Chem. 2021, 40, 256-263 DOI: 10.14102/j.cnki.0254-5861.2011-2851
February 15, 2021
synthesis, silicophosphate, SiO6 octahedral coordination, crystal structure
ABSTRACT
A potassium silicophosphate, K2SiP4O13, has been synthesized in molten polyphosphoric acid. It crystalizes in the triclinic space group P -
ArticleA New 1-D Chain of γ-Hg3S2Br2 Constructed from Hg4S4 Squares: Solid-state Synthesis, Structure and Optical PropertiesDIAO Jian-Feng, XIE Zhi-Xin, LI Pei-Xin and GUO Guo-Cong*
Chin. J. Struct. Chem. 2021, 40, 264-269 DOI: 10.14102/j.cnki.0254-5861.2011-2816
February 15, 2021
crystal structure, metal chalcogenides, resistance, semiconductor, solid-state reaction
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.
- Address: Fuzhou High & New Technology Industrial Zone, Shangjie, Minhou, Fuzhou, Fujian 350108, China
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- E-mail: cjsc@fjirsm.ac.cn