固—液界面阴离子集团构型的密度泛函理论研究

通过键合不同数量的H2PO4^-离子构造了H4P2O8^2-和H4P4O16^8-两种阴离子集 团。利用密度泛函理论对它们的构型进行优化并计算其振动频率和喇曼散射效率。 测量了固—液界面边界层的喇曼光谱并与理论计算结果进行对比分析，进一步研究 了阴离子集团的结构、聚合及脱水等过程。实验和理论研究均表明阴离子二聚体是 KDP晶体的生长基元，他们在固液界面将进一步形成多聚体分子集团，而离子集团 的脱水过程则发生在距KDP晶体表面约50μm的固—液界面边界层中。随着生长层向 界面的推进，这些分子集团将变得越来越有序。本文的研究结果对确定晶体生长界 面动力学过程、发展和完善晶体生长理论有重要意义。     

稀土离子对重组内皮抑素与肝素相互作用的影响

通过荧光光谱法和圆二色谱法研究了重组内皮抑素与稀土离子和肝素的作用.结果表明,稀土离子和肝素都可以与重组内皮抑素结合并引起蛋白的荧光猝灭和二级结构的改变,稀土离子与重组内皮抑素的结合会影响其与肝素的相互作用,并降低重组内皮抑素对人脐静脉内皮细胞的增殖抑制活性.     

新型稀土铁系固体超强酸的制备和三醋酸甘油酯的催化合成

用稀土元素La^3 对铁系固体超强酸Fe2O3／S2O8^2-进行改性,制备出新型稀土铁系固体超强酸催化剂Fe2O3／S2O8^2-/La^3 ,并将其用于催化合成三醋酸甘油酯。酯化反应的最佳条件为：甘油100mmol,n(酸)：n(醇)=6：1,催化剂用量为原料总质量的3．3％,反应时间3h,带水剂苯7mL,酯化率达93％以上。     

Theoretical Studies on Electronic Spectra and Second-order Nonlinear Optical Properties of Barbituric Acid Derivatives Substituted with Schiff Base

Barbituric acid (BA) is a very important kind of compound in biological chemistry and medicine. It can be applied in abirritative medicine and antioxidants.1 It is an important sort of raw material for organic synthe-sis.2 It predicts the important reactive mechanism for organic synthesis.3 Some investigations for NLO prop-erties of a series of BA derivatives have been reported by Feng and coworkers in the view of theory.4,5 The Schiff base has extensive application in the fields of organi…     

Quantum-chemical study of C<Subscript>n</Subscript>F2<Subscript><Emphasis Type="Italic">n</Emphasis>+2</Subscript> conformers. Structure and IR spectra

Quantum-chemical calculations of the geometrical structure and vibrational spectra of C_nF_2n+2 oligomers (n = 5–8) in the chain and branched conformations are reported. The lengthening of the chain of C_nF_2n+2 does not substantially affect the geometrical parameters of the oligomers. In all cases under study, the most optimal structure of the molecule is a zigzag chain with bond lengths R(C-C) = 1.53 –1.54 and R(C-F) = 1.36 –1.34 ; the chain is rolled into a helix, which makes an angle of 17° with the plane. The IR spectra are sensitive to the structural deficiency of oligomers C_nF_2n+2 associated with the lateral trifluoromethyl groups formed in the chain; the spectra can be used for revealing defects of this type in the structure of polytetrafluoroethylene (PTFE). The possibility of defects associated with the lateral CF₃ groups in the structure of PTFE and its low-temperature modifications is explained based on the calculated total energies of C_nF2 _n+2.Original Russian Text Copyright © 2004 by L. N. Ignatieva, A. Yu. Beloliptsev, S. G. Kozlova, and V. M. BuznikTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 632–643, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date.     

荧光光谱法研究钙试剂羧酸钠与牛血清白蛋白结合反应特征

不同温度下,研究了钙试剂羧酸钠与牛血清白蛋白作用的荧光猝灭光谱、同步荧光光谱、三维荧光光谱和紫外可见吸收光谱特征;分别用SternVolmer方程和LineweaverBurk双倒数方程等处理实验数据,得到了26℃时反应的结合常数为7.664×104mol/L,结合位点数为1.522,结合反应的标准焓变、标准熵变和标准吉布斯自由能变分别为-58.36kJ/mol,-101.7J/K和-27.958kJ/mol;分析所得光谱,证实了在实验浓度和温度范围内,CCS与BSA反应可形成具有一定结构的复合物,获得了CCS对BSA构型的影响等重要信息。     

铌酸锂多晶粉体的水热合成及表征

铌酸锂(LiNbO₃)晶体由于本身具有的优良性能在许多领域中都获得了广泛的应用.以LiOH·H₂O和Nb₂O₅为原料采用水热合成法成功地合成了铌酸锂多晶粉体,并采用FTIR谱、XRD谱和SEM对产物进行了表征.结果表明,采用水热合成法能够得到结晶完整的四方柱形LiNbO₃多晶粉体.同时考察了反应温度、晶化时间和Li源对水热合成产物的影响.     

2-(2,5-二羟基苯基)-5-甲基-2,5-二氢吡咯并[3,4]富勒烯的合成和电子光谱的理论研究

利用丙氨酸和2,5-二羟基苯甲醛所形成的亚胺叶立德与C₆₀发生1,3-偶极环加成反应, 合成并分离、纯化制备了一种新的C₆₀吡咯烷衍生物: 2-(2-5-二羟基苯基)-5-甲基-2,5-二氢吡咯并[3,4]富勒烯. 通过¹H NMR, FT-IR, UV-vis和元素分析确定了其结构, 研究了体系的电化学和荧光性质. 采用密度泛函的方法, 在B3LYP/6-31G水平上对分子的几何构型进行了优化, 得到稳定的几何构型; 运用INDO/S方法计算了化合物的电子光谱, 计算结果434.2 nm与实验值432.0 nm基本一致.     

高氯酸稀土Sm(Ⅲ)开环冠醚(EO4)配合物的晶体结构

The crystal of title compounds belongs to orthorhombic system with space group P2₁2₁2₁ (No.19). The cell parmeters are a=1.432 16(3) nm, b=1.457 20(3) nm， c=3.005 85(6) nm, and V=6 273.0(2) nm³, Z=8, μ(Mo Kα)=22.21 cm^-1， D_c=1.802 g·cm^-3, F(000)=3 416.00, Finally R₁=0.033 and wR₂=0.073 (I>2.00σ(I)), S=1.023. Every center atom Sm(Ⅲ) is surrounded by the two aether chains, the title compound has ten-coordinate structure and the coordination polyhedron shows a Bicapped Square Antiprism. In the crystal, the title compound has the flack of double moleculars and non-symmetry. The anion ClO₄^- does not take part in the coordination. CCDC: 238709.     

手性不对称Salen Ni配合物的模板法合成及表征

本文采用过渡金属镍(Ni)作为金属模板合成了2个未见报道的手性不对称Salen Ni配合物，该法具有反应步骤少、纯化处理简单、产率高的显著优点。用¹H NMR、FTIR、UV-Vis、CD光谱及元素分析对配合物进行了详细的表征，证明该模板合成法的可靠性。此外，对该法合成的手性不对称Salen Ni配合物的红外光谱、电子吸收光谱、圆二色光谱的性质做了进一步研究。