The novel complexes, Cp(CO) 2FeTiCp 2Cl(1) and Cp(CO) 2FeSn(CH 2CMe 2Ph) 3(2), were synthesized and characterized by means of elemental analyses and IR spectra, Cp(CO) 2FeSn· (CH 2CMe 2Ph) 3 was addi...The novel complexes, Cp(CO) 2FeTiCp 2Cl(1) and Cp(CO) 2FeSn(CH 2CMe 2Ph) 3(2), were synthesized and characterized by means of elemental analyses and IR spectra, Cp(CO) 2FeSn· (CH 2CMe 2Ph) 3 was additionally characterized by X ray crystal structure analysis. The results of the elemental analyses are in good agreement with the theoretical values. The IR spectra show the existence of η 5 2,4 cyclopentadien 1 yl, carbonyl and methyl groups in the title complexes. The above experimental results show that the M-M bond exists in Cp(CO) 2FeSn· (CH 2Me 2Ph) 3, while the existence of the M-M bond in Cp(CO) 2FeTiCp 2Cl is highly possible, too. Both the two complexes are rather stable towards air and moisture, easily soluble in tetrahydrofuran and toluene, while their solubilities are greatly different in n hexane.展开更多
A new mixed-valence heterometal cluster Mo8VW2VIO26（C5H5N）8·2H2O has been synthesized under solvothermal conditions and characterized by X-ray single-crystal diffraction, IR, UV-vis and XPS spectroscopy. The ti...A new mixed-valence heterometal cluster Mo8VW2VIO26（C5H5N）8·2H2O has been synthesized under solvothermal conditions and characterized by X-ray single-crystal diffraction, IR, UV-vis and XPS spectroscopy. The title compound crystallizes in the triclinic system, space group P1 with a = 11.708（3）, b = 12.018（4）, c = 13.316（4） A, α = 112.184（4）, β = 97.844（4）, γ = 110.043（3）°, V = 1551.9（8） A3 and Z = 1 at 293（2） K. The final full-matrix least-squares refinement converged to R = 0.0414 for 4460 observed unique reflections with I 〉 2σ（I） and w R = 0.1290 for all data（5352） and S = 1.015. In addition, its thermal stability and fluorescent property have also been investigated.展开更多
Molecular structure of a naphthyridine and pyrazine amine ligand, N2,N7-di（pyrazin-2-yl）-1,8-naphthyri-dine-2,7-diamine（H2dpznda 1） was studied, and a three-dimensional supramolecular network with a double helix c...Molecular structure of a naphthyridine and pyrazine amine ligand, N2,N7-di（pyrazin-2-yl）-1,8-naphthyri-dine-2,7-diamine（H2dpznda 1） was studied, and a three-dimensional supramolecular network with a double helix chain structure through intermolecular hydrogen bonds and π-π interactions between the naphthyridine and pyrazine rings was depicted. Through ligand 1, [Co2（μ2-dpznda）2（μ2-CH3OH）2]（2） was obtained and two ligands coordinate to two Co2＋）as tetradentate bridging ligands. Single crystal and magnetism study on 2 revealed that the complex exhibited weak yet significant metal-metal interaction.展开更多
The precise identification of metal-metal bonds is critical to fully understanding the nature of metal-metal bonding but remains a fundamental challenge.Herein,we show the essence of Sc-Sc bonds with a metal-metal dis...The precise identification of metal-metal bonds is critical to fully understanding the nature of metal-metal bonding but remains a fundamental challenge.Herein,we show the essence of Sc-Sc bonds with a metal-metal distance of 3.36 Å in a C_(3v)(8)-C_(82) fullerene cage using crystallography.展开更多
From a quantum mechanical analysis of the melting points of the transition elements the authors put forward a hypothesis that the valence electrons are moving between the occupied orbitals and the empty orbitals as we...From a quantum mechanical analysis of the melting points of the transition elements the authors put forward a hypothesis that the valence electrons are moving between the occupied orbitals and the empty orbitals as well as they are playing a role as "free electrons" moving in the crystal space. Both of these processes constitute a mixed type of metallic bonding. By means of this hypothesis a relation (2/1)m_p/(n_en_o+n_er_a) has been recognised and these values must be crowded in a narrow numerical field. By calculation they are found to be 1.006士0.103 in average.Calculations have also been made on m_p/(n_en_o+n_er_e) and it is found that the ratios of the average values of the three transition periods are 1:1.155:1.322.These are in lmost exact accord with the ratios of the momentum of these periods,i.e.(n+(2/1l(l+1))).By assuming that "free electrons" are responsible essentially for the electro-and thermo-conductions, the average values of (2/1)m_pQ’(or Q") re found to be 1.66士0.26 and 1.65士0.29 for these conductions respectively. Howev-er, there exist regularities in their deviations,implying that the two metallic constitutions must play a coop-erative role in these transfers, and under the ordinary temperatures (between ambient and m. p.)"free elec-trons" play an essential role. At last, the authors have inferred the probable mechanism of superconduc-tivity.展开更多
文摘The novel complexes, Cp(CO) 2FeTiCp 2Cl(1) and Cp(CO) 2FeSn(CH 2CMe 2Ph) 3(2), were synthesized and characterized by means of elemental analyses and IR spectra, Cp(CO) 2FeSn· (CH 2CMe 2Ph) 3 was additionally characterized by X ray crystal structure analysis. The results of the elemental analyses are in good agreement with the theoretical values. The IR spectra show the existence of η 5 2,4 cyclopentadien 1 yl, carbonyl and methyl groups in the title complexes. The above experimental results show that the M-M bond exists in Cp(CO) 2FeSn· (CH 2Me 2Ph) 3, while the existence of the M-M bond in Cp(CO) 2FeTiCp 2Cl is highly possible, too. Both the two complexes are rather stable towards air and moisture, easily soluble in tetrahydrofuran and toluene, while their solubilities are greatly different in n hexane.
基金supported by the National Natural Science Foundation of China(No.21003125,21073190)
文摘A new mixed-valence heterometal cluster Mo8VW2VIO26（C5H5N）8·2H2O has been synthesized under solvothermal conditions and characterized by X-ray single-crystal diffraction, IR, UV-vis and XPS spectroscopy. The title compound crystallizes in the triclinic system, space group P1 with a = 11.708（3）, b = 12.018（4）, c = 13.316（4） A, α = 112.184（4）, β = 97.844（4）, γ = 110.043（3）°, V = 1551.9（8） A3 and Z = 1 at 293（2） K. The final full-matrix least-squares refinement converged to R = 0.0414 for 4460 observed unique reflections with I 〉 2σ（I） and w R = 0.1290 for all data（5352） and S = 1.015. In addition, its thermal stability and fluorescent property have also been investigated.
基金supported by the Natural Science Foundation of Shaanxi Province(No.2013JM2005)the National Science Council of China and the Full-Time Master Innovation Fund of Xi’an Shiyou University(No.2015cx140735)
文摘Molecular structure of a naphthyridine and pyrazine amine ligand, N2,N7-di（pyrazin-2-yl）-1,8-naphthyri-dine-2,7-diamine（H2dpznda 1） was studied, and a three-dimensional supramolecular network with a double helix chain structure through intermolecular hydrogen bonds and π-π interactions between the naphthyridine and pyrazine rings was depicted. Through ligand 1, [Co2（μ2-dpznda）2（μ2-CH3OH）2]（2） was obtained and two ligands coordinate to two Co2＋）as tetradentate bridging ligands. Single crystal and magnetism study on 2 revealed that the complex exhibited weak yet significant metal-metal interaction.
基金Financial support for this research was provided by the National Natural Science Foundation of China(nos.92061204,21771152,and 21721001).
文摘The precise identification of metal-metal bonds is critical to fully understanding the nature of metal-metal bonding but remains a fundamental challenge.Herein,we show the essence of Sc-Sc bonds with a metal-metal distance of 3.36 Å in a C_(3v)(8)-C_(82) fullerene cage using crystallography.
文摘From a quantum mechanical analysis of the melting points of the transition elements the authors put forward a hypothesis that the valence electrons are moving between the occupied orbitals and the empty orbitals as well as they are playing a role as "free electrons" moving in the crystal space. Both of these processes constitute a mixed type of metallic bonding. By means of this hypothesis a relation (2/1)m_p/(n_en_o+n_er_a) has been recognised and these values must be crowded in a narrow numerical field. By calculation they are found to be 1.006士0.103 in average.Calculations have also been made on m_p/(n_en_o+n_er_e) and it is found that the ratios of the average values of the three transition periods are 1:1.155:1.322.These are in lmost exact accord with the ratios of the momentum of these periods,i.e.(n+(2/1l(l+1))).By assuming that "free electrons" are responsible essentially for the electro-and thermo-conductions, the average values of (2/1)m_pQ’(or Q") re found to be 1.66士0.26 and 1.65士0.29 for these conductions respectively. Howev-er, there exist regularities in their deviations,implying that the two metallic constitutions must play a coop-erative role in these transfers, and under the ordinary temperatures (between ambient and m. p.)"free elec-trons" play an essential role. At last, the authors have inferred the probable mechanism of superconduc-tivity.
