含双噻唑高分子及其螯合物的制备和磁性能研究进展

设计和合成有机及高分子磁性材料是当前国内外十分关注的课题,本课题组在先前研究的基础上,以电子理论和磁性理论为指导,从分子设计出发,合成出含双噻唑新型芳杂环聚合物及其过渡金属离子或稀土离子螯合物,测定了它们的磁性能,研究高分子结构、螯合物组成与磁性能的关系,探索产生磁性的机理.发现本研究体系的高分子螯合物具有顺磁居里温度(Tp)高,剩余磁场(Mr)少,矫顽力(Hc)低,是一类很好的软磁性材料,呈现出有一定特色的磁性能.本文综述了含双噻唑高分子过渡金属螯合物、稀土金属螯合物、纳米碳管接枝高分子及其螯合物的制备和磁性能研究,以及典型螯合物的非常规磁性现象的发现和机理探索研究.     

一种光存储用短波长偶氮染料金属螯合物的光谱学与热学特性研究

设计合成一类与短波长(635～650nm)半导体激光器相匹配用于有机光盘的光存储介质的偶氮染料金属螯合物.测定了偶氮染料及其金属螯合物的紫外 可见光吸收光谱,采用分光光度法确定该金属螯合物的结构与组成,计算了它的稳定常数.差热热重分析显示该金属螯合物具有较好的热学性能,有望可作为光记录介质.     

聚丙烯酸双(乙氧羰基)甲酯及其螯合物的合成和磁性能的检测

以溴代丙二酸二乙酯、丙烯酸钠为原料合成了聚丙烯酸双(乙氧羰基)甲酯(PEOCMA),并制备了其相应的与稀土金属Gd3+、Nd3+以及过渡金属Ni2+的高分子螯合物.利用FTIR、1H-NMR、GPC对聚合物和高分子螯合物的结构进行了表征,通过电感耦合等离子质谱仪(ICP)测得了高分子螯合物中的金属含量,借助多功能材料物理特性测试系统(PPMS,physical property measurement system)测定螯合物的磁性能.结果表明这些高分子螯合物具有较高的磁饱和强度,在低温下呈现出一定的铁磁相互作用,且为软磁性材料.     

β一二酮类金属螯合物的毛细管气相色谱行为研究

本文用毛细管气相色谱法研究了三氟乙酰丙酮、三氟-5,5-二甲基-2,4-己二酮及三氟-6-甲基-2,4-庚二酮与铍、铝、铬、铜、铁、钴、镍等金属离子生成螯合物的气相色谱行为,对部分螯合物做了碳氢分析及质谱鉴定,用热重量法考察了这些螯合物有适合于气相色谱法的热性质,采用WCOTOV-101,OV-17及SE-54等色谱柱对这些螯合物进行探讨,在不同柱上得到不同组合螯合物的分离。     

β-二酮类金属螯合物的毛细管气相色谱行为研究

本文用毛细管气相色谱法研究了三氟乙酰丙酮、三氟-5,5-二甲基-2,4-己二酮及三氟-6-甲基-2,4-庚二酮与铍、铝、铬、铜、铁、钴、镍等金属离子生成螯合物的气相色谱行为.对部分螯合物做了碳氢分析及质谱鉴定.用热重量法考察了这些螯合物有适合于气相色谱法的热性质.采用 WCOTOV-101,OV-17及 SE-54等色谱柱对这些螯合物进行探讨,在不同柱上得到不同组合螯合物的分离.     

N-二茂铁甲酰基-芳基羟胺及其铜(Ⅱ)螯合物的合成与表征

二茂铁甲酰羟胺衍生物分子中含有N-羟基和α-羰基,可与过渡金属形成螯合物.我们试图将该类螯合物用作复合固体推进剂的燃速调节剂,为此,研究了该类化合物的合成方法及其性质,并使它们与铜(Ⅱ)螯合制成铜螯合物.     

锆螯合物交联丙烯酸酯共聚物无皂水溶胶的研究Ⅱ锆螯合物与丙烯酸酯三元共聚物无皂水溶胶的交联反应

研究了三元丙烯酸酯共聚物(MMA/BA/AA)无皂水溶胶中加入三乙醇胺锆螯合物对水溶胶及涂膜性能的影响. 在水溶胶中,螯合物增加了共聚物的亲水性,改变了水溶胶的流变性、稳定性、表面张力. 螯合物也提高了共聚物涂膜的耐水性. X光电子能谱(XPS)研究表明,在固化成膜过程中螯合物与共聚物发生交联反应,用IR、1H NMR、DSC、TGA和UV等分析方法对其交联机理作了初步探讨.     

螯合物离子色谱

螯合物离子色谱是一种利用螯合物进行不同方式分离和检测的离子色谱模式，目前已经被痕量金属分析广泛采用，本文对一些螯合物阳离子交换色谱、螯合物色谱、阴离子交换色谱和离子对色谱最新进展进行了综述，并采用基本螯合物化学理论（金属螯合物稳定性、金属原子有效电荷、螯合剂能力等）对保留和分离机理进行了讨论。     

金属材料分析方法的选择和施行 第六讲 金属材料中稀土元素的测定（续）

上节中已提到了CPAⅢ与RE(Ⅲ)离子所生成的螯合物具有比偶氮胂Ⅲ的螯合物更好的光度分析特性,可归纳为以下几点:(1)可在较高一些的微度条件下反应;(2)所生成的螯合物有较高的稳定性;(3)所生成的螯合物的吸收峰向长波方向移动,其色泽的深度和强度明显增加,且与CPAⅢ试剂色泽之间     

稀土有机螯合物发光研究进展

总结了稀土有机螯合物结构与发光性能的关系：配体最低三重态能级与稀土离子激发态能级的匹配是中心稀土离子能否发光的主要因素;螯合物结构的平面性和刚性是中心离子发光效率高低的重要因素;适宜的第二配体的加入一般导致螯合物分子刚性和稳定性增高,因而有利于能量的传递,致使中心离子发光效率增高,但也不能忽视第二配体加入所引起光能的吸收和能量传递过程的竞争;配体的耐热,耐辐射性是配合物能否作为材料的必要因素,自行设计,合成了5类25种新的有机配体及其相应的二元,三元稀土螯合物,研究了这些螯合物的配位性质,发光性能,发光与结构关系及发光机制。提出并发展了稀土离子发光和电子振动光谱作为配合物和生物分子结构探针的两种新的方法。将稀土－β－二酮的发光螯合物与树脂制成荧光塑料;利用铕和铽螯合物的发光和免疫反应,检测了体液中生物活性物质的含量,证实以稀土离子替代放射性同位素作为标记物,有希望替代放射免疫分析方法,成为常规的临床检验方法,利用Tb^3 荧光检测了植物中生长激素的含量。     

水合锰盐18-冠-6的振动光谱

近年来,相继测定了一些过渡金属18-C-6化合物的结构,发现它们的结合方式有着自己的结构特性。作为结构表征的振动光谱,目前还研究得较少。本文合成了(Mn_2Cl_2·8H_20)·18C6·2Cl(Ⅰ)和Mn(NCS)_2·4H_2O·18C6(Ⅱ),测定了4000-100cm~(-1)区域的FTIR和激光Raman光谱,讨论了(Ⅱ)的可能结构。     

Theoretical and experimental study of the vibrational spectrum of N-acetyl-L-alanine

The energies, vibrational frequencies and IR intensities of cis- and trans-N-acetyl-L-alanine (NAAL) are computed using the density functional theory (B3LYP) combined with the 6-311G(d, p) basis set. The trans conformer is characterized by an intramolecular NH ... O hydrogen bond leading to the formation of a five-membered ring and is by 23 kJ mol(-1) more stable than the cis conformer. The difference between the vibrational frequencies and IR intensities computed for the two conformers is discussed. The IR spectra at different temperatures and the Raman spectra of solid NAAL and its deuterated counterpart are investigated and discussed. The frequencies of the v(OH) vibration and the isotopic ratio suggest the formation of short OH ... O hydrogen bonds in the solid state. The NH group seems also to be involved in a weak hydrogen bond.     

Crystal structure and vibrational spectra of AlVO4. A DFT study

We present periodic density functional calculations within the generalized gradient approximation (Perdew-Wang 91) on structure and vibrational properties of bulk AlVO(4). The optimized structure agrees well with crystallographic data obtained by Rietveld refinement (the mean absolute deviation of bond distances is 0.032 A), but the deviations are larger for the lighter oxygen atoms than for the heavier Al and V atoms. All observed bands in the Raman and IR spectrum have been assigned to calculated harmonic frequencies. Bands in the 1020-900 cm(-1) region have been assigned to V-O((2)) stretches in V-O((2))-Al bonds. The individual bands do not arise from vibrations of only one bond, not even from vibrations of several bonds of one VO(4) tetrahedron. The results confirm that vibrations around 940 cm(-1) observed for vanadia particles supported on thin alumina film are V-O-Al interface modes with 2-fold coordinated oxygen atoms in the V-O((2))-Al interface bonds.     

Experimental (FT-IR and FT-Raman) and theoretical (HF and DFT) investigation, IR intensity, Raman activity and frequency estimation analyses on 1-bromo-4-chlorobenzene

The FT-IR and FT-Raman spectra of 1-bromo-4-chlorobenzene (1-Br-4-CB) have been recorded using Bruker IFS 66V spectrometer in the region of 4000-100 cm(-1). Ab-initio-HF (HF/6-311+G (d, p)) and DFT (B3LYP/6-31++G (d, p)/6-311++G (d, p)) calculations have been performed giving energies, optimized structures, harmonic vibrational frequencies, depolarization ratios, IR intensities, Raman activities. The vibrational frequencies are calculated and scaled values are compared with FT-IR and FT-Raman experimental values. Comparison of simulated spectra with the experimental spectra provides important information, the computational method have the ability to describe the vibrational methods. The frequency estimation analysis on HF and DFT is made. The impact of di-substituted halogens on the benzene molecule has also been discussed.     

Vibrational spectroscopic force field studies of dimethyl sulfoxide and hexakis(dimethyl sulfoxide)scandium(III) iodide, and crystal and solution structure of the hexakis(dimethyl sulfoxide)scandium(III) ion

Hexakis(dimethyl sulfoxide)scandium(III) iodide, [Sc(OS(CH(3))(2))(6)]I(3) contains centrosymmetric hexasolvated scandium(III) ions with an Sc-O bond distance of 2.069(3) angstroms. EXAFS spectra yield a mean Sc-O bond distance of 2.09(1) angstroms for solvated scandium(III) ions in dimethyl sulfoxide solution, consistent with six-coordination. Raman and infrared absorption spectra have been recorded, also of the deuterated compound, and analysed by means of normal coordinate methods, together with spectra of dimethyl sulfoxide. The effects on the vibrational spectra of the weak intermolecular C-H...O interactions and of the dipole-dipole interactions in liquid dimethyl sulfoxide have been evaluated, in particular for the S-O stretching mode. The strong Raman band at 1043.6 cm(-1) and the intense IR absorption at 1062.6 cm(-1) have been assigned as the S-O stretching frequencies of the dominating species in liquid dimethyl sulfoxide, evaluated as centrosymmetric dimers with antiparallel polar S-O groups. The shifts of vibrational frequencies and force constants for coordinated dimethyl sulfoxide ligands in hexasolvated trivalent metal ion complexes are discussed. Hexasolvated scandium(iii) ions are found in dimethyl sulfoxide solution and in [Sc(OSMe(2))(6)]I(3). The iodide ion-dipole attraction shifts the methyl group C-H stretching frequency for (S-)C-H...I(-) more than for the intermolecular (S-)C-H...O interactions in liquid dimethyl sulfoxide.     

Vibrational assignment and structure of dibenzoylmethane. A density functional theoretical study

Molecular structure and vibrational frequencies of 1,3-diphenyl-1,3-propanedione, known as dibenzoylmethane (DBM), have been investigated by means of density functional theory (DFT) calculations. The results were compared with those of benzoylacetone (BA) and acetylacetone (AA), the parent molecule. IR and Raman spectra of DBM and its deuterated analogue were clearly assigned.The calculated hydrogen bond energy of DBM is 16.15 kcal/mol, calculated at B3LYP/6-311++G** level of theory, which is 0.28 kcal/mol more than that of AA. This result is in agreement with the vibrational and NMR spectroscopy results. The molecular stability and the hydrogen bond strength were investigated by applying the Natural Bond Orbital analysis (NBO) and geometry calculations. The theoretical calculations indicate that the hydrogen bond in DBM is relatively stronger than that in BA and AA.     

Vibrational assignment of aluminum(III) tris-acetylacetone

The geometry, frequency and intensity of the vibrational bands of aluminum(III) Tris-acetylacetone Al(AA)3 and its 1,3,5-(13)C derivative were obtained by the Hartree-Fock (HF) and Density Functional Theory (DFT) with the B3LYP, B1LYP, and G96LYP functionals and using the 6-31G* basis set. The calculated frequencies are compared with the solid IR and Raman spectra. All of the measured IR and Raman bands were interpreted in terms of the calculated vibrational modes. Most computed bands are predicted to be at higher wavenumbers than the experimental bands. The calculated bond lengths and bond angles are in good agreement with the experimental results. Analysis of the vibrational spectra indicates a strong coupling between the chelated ring modes. Four bands in the 500-390 cm(-1) frequency range are assigned to the vibrations of metal-ligand bonds.     

Vibrational spectra and noncovalent interactions of carbohydrates molecules

The differences between the vibrational spectra of carbohydrates of the same chemical structure caused by the noncovalent intra- and intermolecular interactions have been systematized. In the general case, these differences show up as the following specific features of changes in the bond intensities: change in the intensity ratio of closely spaced bands (IR and Raman spectra); selective change (increase, decrease) in intensities of individual bands (IR and Raman spectra); change (increase, decrease) in intensities of practically all bands (IR and Raman spectra); appearance of strong bands in the region of low frequencies from 50 to 200 cm⁻¹ (Raman spectra); appearance of strong diffuse bands in the low-frequency range with a simultaneous great reduction in the other bands (practical disappearance of the majority of bands) (Raman Spectra). The causes of such a kind of changes in the band intensities in the vibrational spectra of carbohydrates are discussed.     

2-Bromohydroquinone: structures, vibrational assignments and RHF, B- and B3-based density functional calculations

Vibrational spectral measurements, namely, infrared (4000-400 cm(-1)) and Raman (3500-50 cm(-1)) spectra have been made for 2-Bromohydroquinone. Optimized geometrical structures, harmonic vibrational frequencies and intensities have been computed by the ab initio (RHF), B-based (BLYP, BP86) and B3-based (B3P86, B3LYP, B3PW91) density functional methods using 6-31G(d) basis set. A complete assignment of the observed spectra has been proposed. Coupling of vibrations has been determined by calculating potential energy distributions (PEDs) at BP86/6-31G(d) level of theory. In the computed equilibrium geometries by all the levels, the bond lengths and bond angles show changes in the neighborhood of Bromine. Similarly, the vibrational spectra exhibit some marked spectral features unlike in hydroquinone and phenol. On the other hand, the infrared spectrum shows a clear evidence of O-H...O bonding near 3200 cm(-1) as in hydroquinone. Evaluation of the theoretical methods demonstrates that all the levels but the RHF have reproduced frequencies fairly accurately in the 2000-500 cm(-1); below 500 cm(-1) the RHF has performed reasonably well.     

Comparison of experimental and density functional study on the molecular structure, infrared and Raman spectra and vibrational assignments of 6-chloronicotinic acid

The experimental and theoretical study on the structures and vibrations of 6-chloronicotinic acid (6-CNA, C(6)H(4)ClNO(2)) are presented. The Fourier transform infrared spectra (4,000-50 cm(-1)) and the Fourier transform Raman spectra (3,500-50 cm(-1)) of the title molecule in solid phase have been recorded, for the first time. The geometrical parameters and energies have been obtained for all four conformers from DFT (B3LYP) with different basis sets calculations. There are four conformers, C1, C2, C3, and C4 for this molecule. The computational results diagnose the most stable conformer of 6-CNA as the C1 form. The vibrations of the two stable and two unstable conformers of 6-CNA are researched with the aid of quantum chemical calculations. The molecular structure, vibrational frequencies, infrared intensities and Raman scattering activities and theoretical vibrational spectra were calculated a pair of molecules linked by the intermolecular OH...O hydrogen bond. The spectroscopic and theoretical results are compared to the corresponding properties for 6-CNA stable monomers and dimer of C1 conformer.