A diamine monomer o-phenylenedioxybis（5-amino-2-pyridine） was synthesized via reduction of a dinitro compound o-phenylenedioxybis（5-nitro-2-pyridine）, producing a series of new polyimides from this diamine and var...A diamine monomer o-phenylenedioxybis（5-amino-2-pyridine） was synthesized via reduction of a dinitro compound o-phenylenedioxybis（5-nitro-2-pyridine）, producing a series of new polyimides from this diamine and various commercially available aromatic dianhydrides via conventional two-stage processes. The resulting polyimides are able to form tough and transparent films, with decomposition temperatures in the range of 529-551 ℃, and can be dissolved in organic polar solvents. Meanwhile, these polyimides can be degraded in a hydrazine hydrate medium, a degradation mechanism proposed by analyzing the degradation products suggests that the degradable properties could be attributed to the phenyl-2-pyridyl ether structure in the polymer. In addition, the transformation of the compound structure from dinitro compound to damine monomer in the synthetic process is discussed in respect to X-ray structure.展开更多
A polynuclear complex containing a monomer of Cu(Ⅱ)-Zn(Ⅱ) heterobinuclear unit was synthesized and characterized by IR spectra and magnetic moment. The crystal and molecular structure of the complex, CuZnC_(19)H_(24...A polynuclear complex containing a monomer of Cu(Ⅱ)-Zn(Ⅱ) heterobinuclear unit was synthesized and characterized by IR spectra and magnetic moment. The crystal and molecular structure of the complex, CuZnC_(19)H_(24)Cl_4N_2O_2, was determined by X-ray diffraction, it crystallized in monoclinic, P2_1 / m, a = 8.812 (2), b = 15.972(3), c = 8.831(1) A, β = 114.33(1)°, V = 1132.4A^3, Z=2, D_c= 1.710 g / cm^3, λ(Mo K_α) = 0.71073A, μ = 25.227 cm^(-1), R = 0.051. R_w = 0.063 for 1130 ob- served reflections with I> 3σ(I) . The coordinated octahedra of Cu(Ⅱ) and tetrahedra of Zn(Ⅱ) via bridging Cl atoms form a single chain polynuclear complex. The Cu, Zn and bridging Cl atoms are located on the crystallographic symmetry plane m which is perpendicular to 2N and 2O donor plane.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21301137 and 21405120)the New Teachers’Fund for Doctor Stations,Ministry of Education(No.20126101120012)+1 种基金the Scientific Research Program by Shaanxi Provincial Education Department(Nos.12JK0578 and 12JK0617)the Scientific Research Foundation of Shaanxi Provincial Key Laboratory(11JS080 and 12JS087 and by NFFTBS(Nos.J1103311 and J1210057)
文摘A diamine monomer o-phenylenedioxybis（5-amino-2-pyridine） was synthesized via reduction of a dinitro compound o-phenylenedioxybis（5-nitro-2-pyridine）, producing a series of new polyimides from this diamine and various commercially available aromatic dianhydrides via conventional two-stage processes. The resulting polyimides are able to form tough and transparent films, with decomposition temperatures in the range of 529-551 ℃, and can be dissolved in organic polar solvents. Meanwhile, these polyimides can be degraded in a hydrazine hydrate medium, a degradation mechanism proposed by analyzing the degradation products suggests that the degradable properties could be attributed to the phenyl-2-pyridyl ether structure in the polymer. In addition, the transformation of the compound structure from dinitro compound to damine monomer in the synthetic process is discussed in respect to X-ray structure.
文摘A polynuclear complex containing a monomer of Cu(Ⅱ)-Zn(Ⅱ) heterobinuclear unit was synthesized and characterized by IR spectra and magnetic moment. The crystal and molecular structure of the complex, CuZnC_(19)H_(24)Cl_4N_2O_2, was determined by X-ray diffraction, it crystallized in monoclinic, P2_1 / m, a = 8.812 (2), b = 15.972(3), c = 8.831(1) A, β = 114.33(1)°, V = 1132.4A^3, Z=2, D_c= 1.710 g / cm^3, λ(Mo K_α) = 0.71073A, μ = 25.227 cm^(-1), R = 0.051. R_w = 0.063 for 1130 ob- served reflections with I> 3σ(I) . The coordinated octahedra of Cu(Ⅱ) and tetrahedra of Zn(Ⅱ) via bridging Cl atoms form a single chain polynuclear complex. The Cu, Zn and bridging Cl atoms are located on the crystallographic symmetry plane m which is perpendicular to 2N and 2O donor plane.
