A new compound 2 6[Co(H 2O) 2(VO) 8(OH) 4(PO 4) 8] has been hydrothermally synthesized. Single crystal X-ray analysis indicates that this compound crystallizes in a monoclinic system, space group P2 1/n with a=1.438 5...A new compound 2 6[Co(H 2O) 2(VO) 8(OH) 4(PO 4) 8] has been hydrothermally synthesized. Single crystal X-ray analysis indicates that this compound crystallizes in a monoclinic system, space group P2 1/n with a=1.438 5(3) nm, b=1.012 2(2) nm, c=1.832 5(4) nm, β=90.21°, V=2\^668 2(9) nm 3, Z=2, D c=2.112 g/cm 3, R=0.055, wR=0.149 7, S=1.037. The structure of 2 6[Co(H 2O) 2(VO) 8(OH) 4(PO 4) 8] is characterized by P-V-O layers constructed by [(VO) 4(OH) 2(PO 4) 4] 6- non-symmetric units. The P-V-O layers are pillared by [Co(H 2O) 2] 2+ group, resulting in the channels within which the protonated diaminoethane and H 3O + are located.展开更多
The title complex was prepared from self-assembly reaction of La（NO3）3(6H2O, Zn（NO3）2(6H2O, m-cyanobenzoic acid （m-CNC6H4COOH） and pyridine （Py） in refluxing ethanol and its structure was determined by single-...The title complex was prepared from self-assembly reaction of La（NO3）3(6H2O, Zn（NO3）2(6H2O, m-cyanobenzoic acid （m-CNC6H4COOH） and pyridine （Py） in refluxing ethanol and its structure was determined by single-crystal X-ray diffraction. Crystallographic data: C94H62N12La2O22Zn2, Mr = 2120.12, triclinic space group P, a = 13.2219（5）, b = 13.2713（5）, c = 14.1987（6） ?, (???69.156（1）, ( = 84.034（1）, ( = 89.400（1） (, V = 2314.9（2） ?3, Z = 1, Dc = 1.521 g/cm3, F（000） = 1060, ( (MoK（） = 14.94 cm－1, the final R = 0.043 and wR = 0.117 for 6381 unique reflections with I > 2(（I）. Crystal structure determination shows that the neighboring lanthanum（III） and zinc（II） ions are bridged by three bidentate m-cyanobenzonate ligands in the syn-syn fashion to form a pair of dinuclear [LaZn（m-CNC6H4COO）3（Py）（C2H5OH）] subunits, being linked together by two bidentate and two tridentate m-cyanobenzonate groups in the syn-syn and syn-anti modes, respectively, to construct a tetranuclear La-Zn complex [La2Zn2（m-CNC6H4COO）10（Py）2（C2H5OH）2].展开更多
Recent claim of discovering above-room-temperature superconductivity(Tc≈400 K)at ambient pressure in copper doped apatite Pb10(PO_(4))_(6)O has stimulated world-wide enthusiasm and impulse of motion.A lot of follow-u...Recent claim of discovering above-room-temperature superconductivity(Tc≈400 K)at ambient pressure in copper doped apatite Pb10(PO_(4))_(6)O has stimulated world-wide enthusiasm and impulse of motion.A lot of follow-up works have been carried out with controversial conclusions.To check whether superconductivity is really present or absent in the material,we need samples which should have a rather pure phase of Pb_(10-x)Cux(PO_(4))_(6)O.Here we report the characterization results from the Pb_(10-x)Cux(PO_(4))_(6)O with a fraction of about 97 wt.%inferred from the fitting to the X-ray diffraction pattern,if assuming Cu2S as the only impurity.The resistivity measurements show that it is a semiconductor characterized roughly by a ln(1/T)temperature dependence in wide temperature region without trace of superconductivity.Magnetization measurements show that it has a general ferromagnetic signal with a weak superparamagnetic background.Many grains of the sample show clear interactions with a Nb Fe B magnet.The detected Cu concentration is much lower than the expected nominal one.Our results show the absence of metallicity and superconductivity in Pb_(10-x)Cux(PO_(4))_(6)O at ambient pressure,and suggest the presence of strong correlation effect.展开更多
文摘A new compound 2 6[Co(H 2O) 2(VO) 8(OH) 4(PO 4) 8] has been hydrothermally synthesized. Single crystal X-ray analysis indicates that this compound crystallizes in a monoclinic system, space group P2 1/n with a=1.438 5(3) nm, b=1.012 2(2) nm, c=1.832 5(4) nm, β=90.21°, V=2\^668 2(9) nm 3, Z=2, D c=2.112 g/cm 3, R=0.055, wR=0.149 7, S=1.037. The structure of 2 6[Co(H 2O) 2(VO) 8(OH) 4(PO 4) 8] is characterized by P-V-O layers constructed by [(VO) 4(OH) 2(PO 4) 4] 6- non-symmetric units. The P-V-O layers are pillared by [Co(H 2O) 2] 2+ group, resulting in the channels within which the protonated diaminoethane and H 3O + are located.
基金the Natural Science Foundation of China, Fujian Province and Chinese Academy of Sciences.
文摘The title complex was prepared from self-assembly reaction of La（NO3）3(6H2O, Zn（NO3）2(6H2O, m-cyanobenzoic acid （m-CNC6H4COOH） and pyridine （Py） in refluxing ethanol and its structure was determined by single-crystal X-ray diffraction. Crystallographic data: C94H62N12La2O22Zn2, Mr = 2120.12, triclinic space group P, a = 13.2219（5）, b = 13.2713（5）, c = 14.1987（6） ?, (???69.156（1）, ( = 84.034（1）, ( = 89.400（1） (, V = 2314.9（2） ?3, Z = 1, Dc = 1.521 g/cm3, F（000） = 1060, ( (MoK（） = 14.94 cm－1, the final R = 0.043 and wR = 0.117 for 6381 unique reflections with I > 2(（I）. Crystal structure determination shows that the neighboring lanthanum（III） and zinc（II） ions are bridged by three bidentate m-cyanobenzonate ligands in the syn-syn fashion to form a pair of dinuclear [LaZn（m-CNC6H4COO）3（Py）（C2H5OH）] subunits, being linked together by two bidentate and two tridentate m-cyanobenzonate groups in the syn-syn and syn-anti modes, respectively, to construct a tetranuclear La-Zn complex [La2Zn2（m-CNC6H4COO）10（Py）2（C2H5OH）2].
基金supported by the National Key R&D Program of China(Grant No.2022YFA1403201)the National Natural Science Foundation of China(Grant Nos.12061131001,52072170,12204231,and 11927809)the Strategic Priority Research Program(B)of Chinese Academy of Sciences(Grant No.XDB25000000)。
文摘Recent claim of discovering above-room-temperature superconductivity(Tc≈400 K)at ambient pressure in copper doped apatite Pb10(PO_(4))_(6)O has stimulated world-wide enthusiasm and impulse of motion.A lot of follow-up works have been carried out with controversial conclusions.To check whether superconductivity is really present or absent in the material,we need samples which should have a rather pure phase of Pb_(10-x)Cux(PO_(4))_(6)O.Here we report the characterization results from the Pb_(10-x)Cux(PO_(4))_(6)O with a fraction of about 97 wt.%inferred from the fitting to the X-ray diffraction pattern,if assuming Cu2S as the only impurity.The resistivity measurements show that it is a semiconductor characterized roughly by a ln(1/T)temperature dependence in wide temperature region without trace of superconductivity.Magnetization measurements show that it has a general ferromagnetic signal with a weak superparamagnetic background.Many grains of the sample show clear interactions with a Nb Fe B magnet.The detected Cu concentration is much lower than the expected nominal one.Our results show the absence of metallicity and superconductivity in Pb_(10-x)Cux(PO_(4))_(6)O at ambient pressure,and suggest the presence of strong correlation effect.
