Three isostructural lanthanide complexes,namely[Ln(L)_(3)·CH_(3) OH](Ln=Tb(1),Dy(2),Ho(3),HL=N-(pyridin-2-ylcarbamothioyl)benzamide),were successfully synthesized and characterized by IR,UV,elemental analysis,single-crystal X-ray diffraction and DNA-biding analysis.X-ray single-crystal diffractions show that the family of lanthanide complexes crystallizes in monoclinic C2/c space group.Each lanthanide atom is coordinated with three carbonyl-O atoms,three pyridyl-N atoms and three imine-N atoms from three distinct L^(-1) ligands,forming a distorted tricapped trigonal prism.The binding properties of complexes with ct-DNA were studied by simulating the physiological environment of human body.The results suggest that compounds could bind with ct-DNA through interaction under a spontaneous process.
Two isostructural lanthanide complexes, [Tb(salen)2]3·3C2H9N2·4CH4O(1) and [Er(salen)2]3·3C2H9N2·2CH4O(2), where H2 salen = N,N'-bis(3-methoxysalicylidene)ethylene-1,2-diamine, have been in situ synthesized under solvothermal conditions and characterized by IR, elemental analysis, powder and single-crystal X-ray diffraction analysis, and magnetic analysis. Single-crystal X-ray diffraction indicates that the complexes crystallize in monoclinic C121 space group. Each lanthanide center is coordinated with four oxygen and four nitrogen atoms from two salen^2- ligands, forming distorted square antiprism geometry. Both 1 and 2 exhibit obvious slow magnetization relaxation under an applied 2 kOe magnetic field.
BAO Mei-LingTIAN WeiZHANG JunLIAN Qing-YunLI Dong-PingLI Yong-Xiu
A novel zeolite-like metal-organic framework, [Cd12(trz)12'F10'(SiF6)3]·(H3O)4 (Htrz = 1,2,4-triazole), has been synthesized under solvothermal conditions using 1H-l,2,4-triazole-3- carboxylic acid and CdF2 as the starting materials. The complex has been characterized by elemental analysis, IR, SEM-EDS, gas adsorption, powder and single-crystal X-ray diffraction analyses. The title complex crystallizes in the cubic 1-43m space group, with a = 14.6436(8), V= 3140.1(3)A3, Z = 2, Mr = 2857.96, D,.= 3.023 g/cm3 and F(000) = 2668. The final R = 0.0653 and wR = 0.1880 for 586 observed reflections with 1 〉 2σ(I). In the title complex, three adjacent Cd(ll) centers are connected by three p3-bridging triazole ligands to form triagonal secondary building units (SBUs), which are further interconnected to form a three-dimensional skeleton with tetrahedral cages.
A two-dimensional Cd(Ⅱ) coordination polymer, [Cd(dtb)]n (dtb = 5,5 '-dithiobis(2- nitrobenzoic acid), has been solvothermally synthesized and characterized by elemental analysis, IR, TG analysis and single-crystal X-ray diffraction analysis. The complex crystallizes in the monoclinic P21/c space group, with a = 10.7147(10), b = 7.4518(7), c = 22.053(2) A, β = 95.477(2)°, V = 1752.7(3) A3, Z = 4, Mr = 524.74, Dc= 1.989 g/cm3 and F(000) = 1032. The final R = 0.0453 and wR = 0.1201 for 2950 observed reflections with 1 〉 2σ(I). In the complex, the Cd(Ⅱ) ion is coordinated with six oxygen atoms from four different carboxylate groups of dtb ligands and one lattice water molecule. The adjacent Cd centers are interconnected by the flexible carboxylate ligand to form a two-dimensional (2D) structure.
A new Eu(Ⅲ) complex, {[Eu(tta)2(C2H5OH)(NO3)]2(bmp)}·bmp(tta = 2-thenoyltrifluoro- acetonate, bmp = 2,2'-bipyrimidine), has been synthesized and characterized by elemental analysis, IR, luminescence and single-crystal X-ray diffraction analysis. The complex crystallizes in the monoclinic P21/n space group, with a = 11.894(6), b = 14.235(8), c = 19.078(10) A, β = 103.423(9)°, V = 3142(3) A3, Z = 2, Mr = 1721.10, Dc = 1.819 g/cm^3, F(000) = 1696, the final R = 0.0452 and wR = 0.1398 for 5375 observed reflections with I 〉 2σ(I). In the complex, each Eu(Ⅲ) ion is coordinated with four oxygen atoms from two tta ligands and two nitrogen atoms from a bmp ligand, three oxygen atoms from one NO3- anion and one ethanol molecule, forming a distorted tricapped trigonal prism geometry. Luminescence measurement indicates that the europium complex is a strong red emitter in the solid state at room temperature.
Two new transition metal complexes based on chiral Schiff base ligand, namely Zn(L_1)_2(1) and Cd(L_2)2(2)(L 1=(R,E)-3-(2-hydroxy-3-methoxybenzylideneamino)propane-1,2-diol, L2=(R,E)-2-((2-hydroxy-1-phenylethylimino)methyl)-6-methoxyphenol), have been synthesized and characterized. Single-crystal X-ray diffractions reveal that both 1 and 2 crystallize in the same monoclinic space group C_2. 1 is four-coordinated, while 2 is six-coordinated. Complexes 1 and 2 show fluorescent emission at 479 and 580 nm, respectively. Moreover, 1 and 2 exhibit selective and sensitive recognition toward Zn^(2+)/Cd^(2+) ions in the methanol solution.