Synthesis and Crystal Structure of a New Lanthanum(III) 4-Cyanobenzoate Complex

A new dinuclear La（Ⅲ） complex [La2（4-cba）4[H（4-cba）2]2（phen）2（H2O）4] （4-Hcba = 4-cyanobenzoic acid and phen = 1,10-phenanthroline） 1 has been synthesized by solvothermal reaction in an ethanol/water mixed solution at 100 ℃ and structurally characterized by singlecrystal X-ray diffraction. Crystallographic data： C88H58La2N12O20, Mr = 1881.28, triclinic P1, a = 7.518（3）, b = 17.033（6）, c = 17.551（6）A, α = 115.333（4）, β = 92.9910（10）, γ = 99.366（5）°, V = 1985.3（12）A^3, Z = 1, Dc = 1.574 g/cm^3, F（000） = 944 μ = 1.145 mm^–1, the final R = 0.0281 and wR = 0.0686 for 6708 reflections with Ⅰ 〉 2σ（I）. In 1, two nine-coordinated La（Ⅲ） ions are connected by two 4-cba ligands in a syn-syn bidentate coordination mode, and the other six 4-cba ligands terminate the La（Ⅲ） ions, resulting in an isolated dinuclear structure. Two different types of intramolecular hydrogen bonds, asymmetrical O-H…O and symmetrical O…H…O, exist in the crystal. The title complex molecules are connected through hydrogen bonds and weak π-π stacking interactions to generate a 2-D layered network. The thermogravimetric analysis of 1 has also been discussed.

Syntheses and Characterizations of(CH_3CH_2CH_2CH_2NH_3)_6(BiI_6)(I)_2I_3 and (NH_3CH_2CH_2NH_3)_2Bi_2I_(10)

The title compounds have been respectively synthesized by solution process and solvothermal reaction, and their crystal structures were determined by X-ray diffraction method. For （CH3CH2CH2CH2NH3）6（BiI6）（I）2I3 1, it crystallizes in tficlinic, space group P1^- with Mr = 2049.76, a = 8.5719（1）, b = 11.7461（3）, c = 15.700（1）A, V = 1451.4（1）A^3, Z = 1, Dc = 2.345 g/cm^3, F（000） = 924, μ（MoKα） = 8.907 mm^-1, T = 293（2） K, the final R = 0.0655 and wR = 0.0804 for 2399 observed reflections with I 〉 2σ（I）. For （NH3CH2CH2NH3）2Bi2I10 2, it crystallizes in monoclinic, space group P21/n with Mr= 1811.20, a = 8.434（4）, b = 13.862（6）, c = 13.362（6）A, V = 1499.9（12）A^3, Z = 2, Dc = 4.010 g/cm^3, F（000） = 1536,μ（MoKα） = 22.007 mm^-1, T = 293（2） K, the final R = 0.0584 and wR = 0.1451 for 1798 observed reflections with I 〉 2σ（I）. The structures of 1 and 2 contain halobismuthate monomer and dimers, respectively. It is noteworthy that the dimers and their organic counters in 2 connect each other by N…I hydrogen bonds to form a layered structure, and the electrostatic interactions and crystal packing forces between layers give rise to the packing of the crystal. The optical absorption spectra of 1 and 2 reveal the appearance of sharp optical gaps of 2.13 and 2.01 eV, respectively.

One-dimensional Supramolecular Chain Based on a Dinuclear Terbium(Ⅲ) 4-Cyanobenzoate Complex

A new dinuclear Tb（Ⅲ） 4-cyanobenzoate complex [Tb2（4-cba）6（phen）2] （4-Hcba = 4-cyanobenzoic acid and phen = 1,10-phenanthroline） 1 has been synthesized by solvothermal reaction in an ethanol/water mixed solution at 100℃ and structurally characterized by single-crystal X-ray diffraction. Crystallographic data： C72H40N10O12Tb2, Mr=1554.98, triclinic Pi, a = 9.903（3）, b = 11.769（8）, c = 15.078（8）A, a = 111.42（12）, It = 96.37（19）, γ = 101-24（14）°, V= 1572（1）A3, Z= 1, Dc = 1.642 g/cm^3, F（000） = 768 μ = 2.305 mm^-1, the final R = 0.0205 and wR = 0.0543 for 5479 reflections with I 〉 2σ（I）. Structural analysis shows that 1 displays an isolated dinuclear structure. Two eight-coordinated Tb（Ⅲ） ions are bridged by four 4-cba ligands in the syn-syn bidentate coordination mode, and two other 4-cba ligands chelate these two Tb（Ⅲ） ions. The title complex molecules are connected through π-π stacking interactions to generate a one-dimensional supramolecular chain, The characteristic infrared spectra, luminescent properties and thermogravimetric analyses have also been discussed.

Modulating p-d orbital hybridization by CuO/Cu nanoparticles enables carbon nanofibers high cycling stability as anode for sodium storage

Carbon nanofibers(CNFs)have been extensively studied as anode materials for sodium-ion batteries due to their high conductivity,large aspect ratio and good electrochemical stability.The low specific capacity and low first cycle efficiency of CNFs,however,have hindered its practical application.Herein,we present a facile strategy to synthesize a novel CNFs decorated with Cu/CuO nanoparticles(Cu-CNFs)using magnetron sputtering method.Cu/CuO nanoparticles were uniformly distributed on the surface of CNFs.According to the density functional theory(DFT)calculation,Cu/CuO nanoparticles d-orbitals and CNFs p-orbitals present hybridization states,and the Na~+adsorption energy of the modified CNFs decreases from-2.14 to-2.97 eV.The Cu-CNFs composites exhibit excellent sodium storage properties,presenting a desirable initial Coulombic efficiency of 76%and a high specific reversible capacity of 300 mAh·g^(-1)at 0.1 A·g^(-1)after 400 cycles.Cu-CNFs anode has excellent cycling stability under high current density,maintaining a high capacity of 150 mAh·g^(-1)at 1 A·g^(-1)after 6000 cycles.Using magnetron sputtering to regulate the electronic structure provides a new thought for improving the electrochemical performance of carbon materials.

NIR-to-NIR UCL/T_1-weighted MR/CT multimodal imaging by NaYbF_4:Tm@NaGdF_4:Yb-PVP upconversion nanoparticles

Multimodal imaging nanoprobes are urgently sought because they can integrate different imaging function into individual nanoplatform and provide more comprehensive and accurate information for the diagnosis of early-stage tumor.Lanthanide-based upconversion nanoparticles(UCNPs) are regarded as promising nanoplatforms to fabricate these probes.Herein,we firstly developed the active core-active shell structured NaYbF_4:Tm@NaGdF_4:Yb-PVP UCNPs with the average diameter of 13.23±0.96 nm as multimodal imaging probes.These water-dispersible nanoprobes presented excellent near-infrared to near-infrared(NIR-to-NIR) upconversion luminescence(UCL) performance,which is favorable for optical bioimaging due to deeper tissue penetration and autofluorescence reduction.After coated with the NaGdF_4:Yb active shell,the UCL emission intensity at 800 nm increased by 7.2 times.These nanoprobes exhibited a desirable longitudinal relaxivity(r_1=3.58 L/(mmol s)) and strong X-ray attenuation property(58.84 HU L/g).The cytotoxicity assessment,histology analysis and biodistribution study revealed that NaYbF_4:Tm@NaGdF_4:Yb-PVP UCNPs had relatively low cytotoxicity and negligible organ toxicity.These UCNPs were applied for NIR-to-NIR UCL imaging in vivo.More importantly,the detection of small tumor was successfully achieved under T_1-weighted MRI and CT imaging modalities after intravenous injection of these UCNPs.These results revealed that NaYbF_4:Tm@NaGdF_4:Yb-PVP UCNPs could serve as promising NIR-to-NIR UCL/MRI/CT trimodal imaging probes.