A Novel 3D Cobalt（II） Complex Constructed by 2,2＇-（1,4-Butanediyl）bis（1H-benzimidazole） Ligand

A novel 3D polymer 1 (C26H22CoN4O4, Mr = 513.41) constructed from H2C4BIm (2,2'-(1,4-butanediyl)bis(1H-benzimidazole)], 1,3-bdc (1,3-benzenedicarboxylate) and Co(II) has been successfully synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction analysis. The crystal belongs to the tetragonal system, space group I-42d with a = 24.315(5), b = 24.315(5), c = 8.343(2), V = 4933(2)3, Z = 8, Dc = 1.383 g/cm3, μ(MoKα) = 0.735 mm-1, F(000) = 2120, S = 1.156, the final R = 0.0596 and wR = 0.1346 for 1529 reflections with I > 2σ(I). Complex 1 contains 1D chains which are connected by extensive hydrogen-bonding interactions to form the 2D folded layer and 3D framework, which also stabilize the structure.     

Synthesis of large surface area nano-sized BiVO4 by an EDTA-modified hydrothermal process and its enhanced visible photocatalytic activity

In this work, monoclinic scheelite-type BiVO₄ nanoparticle with large surface area has been successfully synthesized, using Bi(NO₃)₃ and NH₄VO₃ as raw materials, through a hydrothermal process in the presence of ethylene diamine tetraacetic acid (EDTA). It is demonstrated that the nanoparticle size of as-prepared BiVO₄ becomes small by decreasing hydrothermal temperature, shortening hydrothermal reaction time and increasing EDTA amount used. The resulting BiVO₄ nanoparticle with large surface area exhibits a good photocatalytic performance for degrading phenol solution as a model organic pollutant under visible illumination. The key of this method is the chelating role of EDTA group in the synthetic process that it can greatly control the concentration of Bi³⁺, leading to the growth inhibition of BiVO₄ crystallite. The work provides a route for the synthesis of Bi-containing nano-sized composite oxides with large surface area.     

Structural and optical properties of Ga2O3:In films deposited on MgO (1 0 0) substrates by MOCVD

Ga₂O₃:In films with different indium (In) content x [x=In/(Ga+In) atomic ratio] have been deposited on MgO (1 0 0) substrates by metalorganic chemical vapor deposition (MOCVD). Structural analyses revealed that the film deposited with actual In content (x′) of 0.09 was an epitaxial film and the films with x′=0.18 and 0.37 had mixed-phase structures of monoclinic Ga₂O₃ and bixbyite In₂O₃. The absolute average transmittance of the obtained films in the visible region exceeded 95%, and the band gap was in the range of 4.74-4.87 eV. Photoluminescence (PL) measurements were performed at room temperature, in which the visible luminescences were strong and could be seen by the naked eye. The strong emissions in the visible light region were proposed to originate from the gallium vacancies, oxygen deficiencies and other defects in these films.     

Phonons in isostructural (ND,Yb):YxGd1−x(VO4) laser crystals: A Raman scattering study

The room temperature phonon modes of the isostructural (Nd,Yb):Y_xGd_1−x(VO₄) laser crystals were determined using the Raman scattering technique, and the observed wavenumbers follow the overall mode distribution expected for REVO₄ (RE=rare earth) compounds with the tetragonal zircon structure, . They were assigned according to the group theory in terms of the internal modes of the VO₄ tetrahedron and the external modes of the Y_xGd_1−x(VO₄) lattice. No appreciable changes in the phonon wavenumbers were observed for Yb:GdVO₄ (Yb=0.008, 0.015, 0.020, 0.025, and 0.035), indicating that the force fields in the GdVO₄ lattice are not strongly altered by Yb doping at the Gd site. However, most of the phonon wavenumbers in the systems (Nd,Yb):Y_xGd_1−x(VO₄) shifts upwards (one-phonon-like behavior) when Y replaces for Gd.     

超大孔P(AA-co-AM)/PVA水凝胶的制备及吸附性能研究

采用泡沫分散聚合法,以饱和Na2CO3水溶液为发泡剂,过硫酸铵(APS)及NaHSO3为引发剂,N,N′-亚甲基双丙烯酰胺(MBA)为交联剂,聚(氧化乙烯/氧化丙烯)(PF127)为泡沫稳定剂,丙烯酸(AA)和丙烯酰胺(AM)为单体,聚乙烯醇(PVA)为第二网络,制备超大孔半互穿水凝胶P(AA-co-AM)/PVA,并研究其对阳离子兰染料的吸附性能。研究表明,P(AA-co-AM)/PVA具有相互贯穿的超大孔结构;当n(AM):n(AA)=1.5:1,w(PVA)=1.6%时凝胶的平衡溶胀度达186.56g/g;凝胶具有很好的离子响应性,在蒸馏水中的平衡溶胀度为129.16g/g时,在0.1mol/L NaCl溶液中只有31.07g/g;对阳离子兰染料溶液的脱色率达92.17%,吸附容量达17.16mg/g。     

碳硼烷桥连噻吩化合物结构和二阶非线性光学系数的DFT计算

采用密度泛函理论(DFT)B3LYP方法,计算分析了7个以碳硼烷和苯环为桥连基团化合物的非线性光学(NLO)特征,结果表明:桥连基团的体积越大,对提高极化率的值越有利;分子桥连部分的电子离域性以及分子的几何构型对二阶NLO系数有重要影响,电子跃迂时的电荷转移程度对二阶NLO性质有较大贡献.通过分析分子的电子光谱和对应的...     

Structure elucidation and complete NMR spectral assignment of an unusual aromatic monacolin analog from Monascus purpureus-fermented rice

One unusual aromatic monacolin analog, monacophenyl, was isolated from the ethanolic extract of Monascus purpureus-fermented rice. Its structure was completely and unambiguously assigned by one- and two-dimensional NMR techniques ((1)H NMR, (13)C NMR, HSQC, HMBC and NOESY) and high-resolution ESI-MS spectrometry.     

Impact of nanomaterials on high-throughput separation methodologies

Due to the unique properties, such as their large surface to volume ratio and easy modification, nanomaterials have recently been studied as effective sorbents in the field of separation science. It has proven to be more effective and efficient to use nanoparticles (NPs) as a stationary phase in solid-phase extraction separation. In addition, NPs can be also used as buffer additives in capillary electrophoresis separation. This review highlights recent developments in high-throughput separation methodologies employing nanomaterials such as carbon nanotubes, gold nanoparticles and magnetic NPs etc.     

Quantitative structure-wavelength relationship modeling of porphin: derivative photosensitizers

A linear quantitative structure-visible light absorption wavelength (λ) relationship model for one hundred and forty-two photosensitizers was proposed using heuristic method and multiple linear regression analysis. The statistical parameters of the model were R2 = 0.916; F = 372.16; and RMSE = 5.0873. A fivefold cross-validation algorithm was applied, and the results indicated that the model has a satisfactory statistical stability and validity. The proposed model was evaluated for predictive ability with an external validation set, and the statistical parameters obtained were and R2EXT = 0.908; Q2EXT = 0.897; F = 118.14; and RMSEEXT = 5.6338 for the external test set. The results obtained demonstrated that the simple linear quantitative structure-wavelength relationship model was robust and satisfactory. It could be a feasible and effective tool for predicting λ of photosensitizers, which is an important parameter for their effect on photodynamic therapy for cancer, and could be a potential way for instructing synthesis of this kind of new photosensitizers.