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含钆杂多配合物对水氢核的弛豫性能 总被引:1,自引:0,他引:1
核磁共振成像(MRI)技术是继CT扫描仪后又一诊断肿瘤的有力工具,已广泛应用于临床.MRI成像时,不同组织间的区别是由于这些组织中水分子的1H核磁弛豫时间的差别引起的.但病变与正常组织的弛豫速率的差别常常达不到诊断的目的,因此诊断时常使用造影剂,其作用是改变体内局部组织中水质子弛豫时间,提高正常与患病部位的成像对比度[1].造影剂的使用要求具有较高的弛豫效率、较高的稳定性,无毒等条件.弛豫效率与化合物中顺磁原子的未成对电子数有关,未成对电子数越多,则配合物的电子自旋磁矩越大,对邻近水质子的弛豫能力越强.因此,研究较多的是… 相似文献
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EDDS与THEC的钆(Ⅲ)配合物的合成及其对水质子的弛豫性能研究吕正荣,卓仁禧,尹超,周建威(武汉大学化学系,武汉,430072)(中国科学院武汉物理研究所)关键词天冬氨酸衍生物,胱氨酸衍生物,钆(Ⅲ)配合物,弛豫性能在磁共振成像(MRI)技术中,... 相似文献
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通过二乙三胺五乙酸二酐(DTPAA)分别与N-正丁基、正辛基、苄基、对甲苯磺酰基、苯基和对溴苯基取代二乙醇胺共聚,制得一系列大分子配体及其钆(III)配合物.对所合成的配体和钆配合物进行了表征,并测试了部分钆配合物的核磁弛豫性能. 相似文献
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通过二乙三胺五乙酸二酐(DTPAA)分别与L-N,N-双(2-羟乙基)取代的丙氨酸、苯丙氨酸、缬氨酸、亮氨酸、异亮氨酸和N,N-双(2-羟乙基)甘氨酸共聚,制备了六个大分子聚酯配体及其轧(Ⅲ)配合物。对所合成的配体和钆配合物进行了表征,并测试了部分钆配合物的弛豫性能。 相似文献
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一个新型碗状双核配合物的合成及结构表征 总被引:2,自引:0,他引:2
采用挥发法,在无水条件下合成了一个新型具有碗状结构的双核稀土金属配合物:[Y2(L)(HL)(NO3)6(HCOO)]·3CH3OH[L=1,3,5-三(1-咪唑基-亚甲基)-2,4,6-三甲基苯] (1)。并通过元素分析、FT-IR、电喷雾质谱及X-射线单晶衍射对其进行了表征。结构分析表明该化合物属于正交晶系,空间群为Pnnm,晶胞参数为a=1.952 42(15) nm,b=1.875 28(19) nm,c=1.682 25(15) nm,晶胞体积V=6.159 3(10) nm3,Z=4。在化合物1中,两个独立的Y(Ⅲ)均为九配位,并通过甲酸根桥联,而两个配体采用不同的构象作为二齿配体参与与Y(Ⅲ)的配位,一个为cis,cis,cis-构象,另一个为cis,trans,trans-构象。 相似文献
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聚酯—酰胺型MRI造影剂的合成及其弛豫性能研究 总被引:1,自引:0,他引:1
通过二乙三胺五乙酸双酸酐分别与乙醇胺、L—丝氨酸及其乙酯、L—酪氨酸及其甲酯、苄酯、正辛酯共聚,合成了七种大分子配体,制备了它们的Gd(Ⅲ)配合物,并进行了表征。测试其中五种水溶性配合物的弛豫性能。结果表明它们具有与Gd(DTPA)相当或更强的弛豫性能。 相似文献
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Co-btec配合物的合成、结构及表面光电性能 总被引:1,自引:1,他引:1
采用水热以及微波合成方法得到了3 种Co(II)配合物: [Na2Co(μ4-btec)(H2O)8]n(1)、[Co2(μ2-btec)(bipy)2(H2O)6]·2H2O(2)和[Co2(μ2-btec)(phen)2(H2O)6]·2H2O (3) (H4btec=1,2,4,5-苯四甲酸, bipy= 2,2'-联吡啶, phen=邻菲咯啉). X 射线单晶衍射结果表明, 配合物(1)属于单斜晶系, C2/m空间群, 晶胞参数为a=1.5690(2) nm, b=0.9550(6) nm, c=0.6102(2) nm, β=92.78(3)°. 配合物(2)也属于单斜晶系, P21/n 空间群,晶胞参数为a=1.2290(1) nm, b=0.7594(2) nm, c=1.7920(1) nm, β=100.07(2)°. 配合物(3)属于三斜晶系, P1空间群, 晶胞参数为a=0.7454(1) nm, b=1.1072(2) nm, c=1.2177(2) nm, α=108.41(3)°, β=101.94(3)°, γ=109.03(3)°. 3个配合物都是以均苯四甲酸根为桥, 形成三维(1)和双核(2、3)结构. 但在3种配合物中, 均苯四甲酸根的配位模式各不相同, 分别采用了μ4-η2η2η2η2、μ2-η1η1和μ2-η1η1配位模式.此外,分子间大量氢键又将配合物(2)和(3)分别网成了二维和三维无限结构. 通过红外光谱(IR)、紫外-可见-近红外(UV-Vis-NIR)光谱及表面光电压光谱(SPS)等方法对配合物进行了表征. 3个配合物的表面光电压谱研究表明, 它们在300-600 nm 范围内均有正的光伏响应. 但它们的SPS响应带的宽度、位置和数目存在一定差异, 这是由它们的结构和三者中Co 离子的配位微环境不同造成的. 将SPS与其电子吸收光谱进行关联, 发现它们基本上是一致的. 相似文献
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对苯二甲醛缩二氨基硫脲-钆配合物的合成及阴离子识别研究 总被引:1,自引:0,他引:1
合成了化合物(2E,2′E)-2,2′-(1,4-苯基双亚甲基双硫代氨基脲)(C10H12N6S2)(L),利用L与钆离子形成了配合物(GdL)。用UV-Vis吸收光谱考察其与F-、Cl-、Br-、I-、Ac-、NO3-、HSO4-和H2PO4-等阴离子的识别。研究表明,加入F-或H2PO4-时,溶液颜色由无色变为黄色,加入其它阴离子没有变化,从而实现受体对这两种阴离子的检测。Job法表明主客体间形成1∶1配合物。受体对两种离子的识别作用主要源于配合物多余的结合位点。在此基础上,以GdL的DMSO溶液作为起始状态,以F-和H2PO4-为两化学输入,构建了一个"或"(OR)分子逻辑门。 相似文献
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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) , β = 103.423(9)o, V = 3142(3) 3, Z = 2, Mr = 1721.10, Dc = 1.819 g/cm3, 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. 相似文献
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α-十四烷基-DOTA及其钆(Ⅲ)螯合物的合成与表征(英) 总被引:4,自引:0,他引:4
Synthesis and characterization of the ligand, [10-(α-tetradecylcarboxymethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid, H4L] and its Gd(Ⅲ) chelate are described. Protonation constants for H4L(lgKiH = 10.62, 9.50, 4.74, 4.12) and the stability constant for GdL-(lgKGdL-= 24.60) were determined by potentiometric titrations. The results obtained show that the basicity of the ligand is not significantly altered and the ligand still maintains the strong chelating properties of the parent DOTA after introduction of a linear chain tetradecyl group at the acetic side chain of DOTA. 相似文献
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Synthesis and characterization of the ligand, [2-tetradecyl-3,6,9-tris(carboxymethyl)-3,6,9-triazaundecan-1,11-dioic acid, H5L] and its Gd(Ⅲ) chelate are described. Protonation constants for H5L (lgKiH = 10.80, 8.40, 4.30, 2.80, 2.15) and the stability constant for GdL2- (lgKGdL2-= 22.75) were determined by potentiometric titration and are similar with the related values of DTPA and Gd-DTPA respectively. The results obtained show that the basicity of the ligand and the stability constant of its Gd(Ⅲ) chelate are not obviously altered after introduction of a linear chain tetradecyl group at the terminal acetic acid residue of DTPA. 相似文献
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小分子造影剂在体内存留的时间较短,被注射到体内后,在较短的时间内就会排出体外,所以在进行造影检查时,需要多次注射造影剂.一般大分子造影剂,比小分子造影剂[如二乙三胺五乙酸(DTPA)钆的配合物等]有更好的弛豫效能,而且大分子造影剂在体内停留的时间较长,能满足造 相似文献
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《中国化学会会志》2017,64(4):412-419
A new tetranuclear Zn(II ) complex, [{Zn(L)(μ‐OAc )Zn(H2O )}2], based on an asymmetrical salamo‐type bisoxime chelating ligand H3L (6‐hydroxy‐4′‐chloro‐2,2′‐[ethylenediyldioxybis(nitrilomethylidyne)]diphenol) was synthesized and characterized by elemental analyses, differential thermal methods, single‐crystal X‐ray crystallography, and IR , UV –vis, and fluorescence spectra. The Zn(II ) complex crystallizes in the triclinic system, space group P ‐1 with cell parameters a = 9.0742(6) Å, b = 11.8225(5) Å, c = 12.4182(8) Å, Z = 2, V = 1212.56(12) Å3 , R 1 = 0.0572, and wR 2 = 0.1734. The environment of the tetranuclear Zn(II) complex is penta‐coordinated having a slightly distorted trigonal bipyramidal geometry. Moreover, a 1D chain supramolecular structure is formed along the c ‐axis by the intermolecular C1–H1B⋯O14 hydrogen bonds; in the same manner, C2–H2C⋯Cg2 functions in the formation of supramolecular structures along the a ‐axis of the 1D chain. A 2D supramolecular structure along the ac plane extends infinitely under the force of intermolecular hydrogen bonds. Differential scanning calorimetry‐thermogravimetry thermal analysis provides evidence of the coordination of Zn(II) atoms to the ligand H3L. The Zn(II) complex shows intense photoluminescence with a maximum emission at ~453 nm upon excitation at 360 nm. 相似文献
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Synthesis, Crystal Structure and Thermal Property of a Manganese(II) 4-Carboxyphenoxyacetate Complex
1 INTRODUCTION Organic aromatic carboxylic acids which com-monly possess multiple coordination modes are ex-cellent candidates for constructing supramolecularmetal complexes[1~6]. 4-Carboxyphenoxyacetic acid(4-CPOAH2), widely used in biological activitystudies, is a multidentate flexible ligand that not onlyhas versatile binding possibilities but also can formregular hydrogen bonds as both hydrogen-bond donorand acceptor. However, there have been few reportson the coordination chemistr… 相似文献