金属离子媒染对天然染料色光的影响

采用锌、铝、铁3种金属离子作媒染荆.分别与天然染料胭脂虫酸、栀子黄制成配合物溶液及配合物.测定了配合物溶液的紫外一可见光谱.分析并阐述了天然染料与金属离子配合前后的最大吸收波长、吸光度因参与配合反应的天然染料结构和金属离子种类的不同,而发生了不同程度的变化,进而改变了天然染料发色体系电子跃迁的能级间隔,从而改变天然染料的色光,胭脂虫酸色光的影响要大于栀子黄;测定了配合物的红外光谱,分析并阐述了两种天然染料中的一些可配位基团与金属离子发生了配合反应,且金属离子的种类及染料的结构不同,其相互间的配合能力也不同,胭脂虫酸配合能力强于栀子黄.     

鞣性金属与甘氨酸配位作用的红外光谱研究

对鞣性多金属离子Ｃｒ，Ｌｎ的甘氨酸固体配合物的红外光谱进行了归属，计算了羧基的反对称和对称伸缩振动的差值讨论了金属离子与甘氨酸配体之间的化学键性质，分析了金属离子的鞣制性能和配合物的结构特征。     

四环素类金属离子配合物应用研究进展

四环素类抗生素是一类具有氢化骈四苯环的广谱抗生素,由于这类抗生素带有可配位活性基团和合适的空间构型,因而可与金属离子配位形成稳定的配合物。研究表明四环素类金属离子配合物与四环素具有着不同的生物、化学及物理性质。本文介绍了四环素类药物与金属离子的配位机制,综述了其配位化学在分析检测、药物研发和环境评价等方面的应用,并对四环素金属配合物研究发展方向进行了展望。     

改性壳聚糖Cu(Ⅱ)配合物树脂对肌红蛋白的水解作用研究

以壳聚糖树脂和金属离子Cu(II)为原材料,制备可重复使用的改性壳聚糖Cu(II)配合物树脂(CMCR)。利用茚三酮比色法和SDS-PAGE电泳法研究CMCR对肌红蛋白(Mb)的催化水解作用。研究结果表明:在生理pH,60℃条件下,CMCR可高效催化水解Mb,24h后Mb的水解率在80%以上。CMCR负载Cu(II)具有很高的稳定性,1次水解反应后仍可保留98.17%的金属离子。CMCR本身具有很好的稳定性,重复使用4次后仍保持85%以上的催化水解活力。CMCR作为新型水解蛋白的介质,在食品等领域具有广泛的应用前景。     

PVA-Fe(Ⅲ)配合物功能纤维的性能研究

由于聚乙烯醇纤维大分子中的-OH含有孤对电子对,可与金属离子发生配位反应.为了制备PVA-Fe(Ⅲ)配合物纤维,并分析其性能特征,首先对聚乙烯醇纤维进行了初步处理,然后使其与Fe(Ⅲ)反应,从而制得PVA-Fe(Ⅲ)配合物纤维.测试了PVA-Fe(Ⅲ)配合物纤维的力学性能、吸湿性能以及电学性能,PVA-Fe(Ⅲ)配合物功能纤维与原PVA纤维相比具有较大差异,通过控制金属离子含量,可提高纤维断裂强度和体积比电阻.     

壳聚糖对锌(铁)离子的配位特性及其配合物的应用

壳聚糖与金属的配合物兼有壳聚糖和配位金属离子的特性,在很多方面都表现出了比配合物各组分单独使用更优越的性能,因而在营养保健、食品添加剂、医药、农业等领域有巨大的应用潜力.本文重点介绍了壳聚糖与锌、铁离子的配合物的物理性质、配合特性、结构分析、及应用领域等方面的研究现状,展示了对壳聚糖-金属配合物研发、利用的广阔前景.     

正交试验优化染料木素-锌配合物合成工艺

以天然活性成分染料木素为配体,与锌金属离子配位,合成染料木素-锌配合物。以配合物产率为考察指标,采用单因素试验和L_9(3~4)正交试验设计确定染料木素-锌配合物的最佳合成工艺条件,同时采用紫外光谱法和红外光谱法对染料木素-锌配合物进行了结构表征。结果表明,合成工艺中各因素的影响次序为反应pH反应温度反应时间,染料木素-锌配合物的最优合成工艺条件为反应pH 9.0、反应温度60℃、反应时间6 h,此条件下配合物的产率达39.67%。结构表征结果初步显示染料木素是通过4位羰基和5位羟基与锌金属离子进行配位的。筛选的合成工艺可有效提高染料木素-锌配合物的产率。     

麦麸提取物对晚期糖基化终产物的抑制研究

本文运用配位效应将木犀草素与金属离子Zn2+和Mn2+反应生成了木犀草素配合物,采用了红外、紫外、热重及元素分析对配合物进行了结构表征,同时研究了对黄嘌呤氧化酶的抑制作用,比较了木犀草素及其配合物抑制能力的大小,确定了对黄嘌呤氧化酶的抑制作用类型。结果表明,木犀草素与金属离子Zn2+和Mn2+发生了配位反应,形成了稳定的配合物,配合位点位于A环的5-OH及C环的4-C=O处。相比于木犀草素,木犀草素配合物对黄嘌呤氧化酶表现出更好的抑制效果,通过固定黄嘌呤底物浓度为0.6 mmol/L,酶浓度对酶活力作图可知,木犀草素及其配合物对黄嘌呤氧化酶的抑制类型均属于可逆抑制,通过固定黄嘌呤氧化酶浓度为10 μg/mL,用Lineweaver-Burk双倒数作图,木犀草素及其配合物对黄嘌呤氧化酶的抑制类型表现为竞争性抑制。     

芦丁金属配合物的制备及抑菌活性研究

研究了芦丁与Cu(Ⅱ)、Zn(Ⅱ)、Mn(Ⅱ)形成的金属离子配合物的合成、初步表征及其抑菌活性.结果表明,配合物的组成为[M3L2(H2O)n](CH3COO)2(n=1,2,3…),配体不饱和环的3个羟基参与了金属离子的配位作用;测定其摩尔电导率和红外光谱,对其抑菌活性较为显著.     

偕胺肟双金属配合物纤维的制备及物理性能

通过控制金属离子的浓度和反应时间制得一系列不同金属含量的双金属配合物纤维。分别对不同金属含量的单、双金属配合物的断裂强度、断裂伸长率、初始模量、回潮率等物理机械性能进行了分析。结果表明,各种配合物的断裂强度、断裂伸长率与配合物中金属含量密切相关,金属含量很低时,其值比聚丙烯腈纤维(PAN)的低,随金属含量增加可达与PAN相当值;与PAN相比,回潮率增大,初始模量减小,双金属配合物具有良好的可纺性能。     

Transformation of the plant growth regulator daminozide (Alar) and structurally related compounds with CuII ions: oxidation versus hydrolysis

As part of a study of metal ion effects on chemical transformations of nitrogen-containing agrochemicals, conversion of daminozide to succinate via cleavage of the hydrazide C-N bond was examined in the presence and absence of divalent metal ions. No conversion was observed in metal ion-free solutions or in the presence of 1.0 mM NiII, ZnII, and PbII. CuII, in contrast, markedly increased rates of daminozide to succinate conversion. Halide ions (CI-, Br-) had no effect on daminozide conversion in the absence of metal ions but markedly increased conversion rates observed in the presence of CuII. The nitrogen-donor ligands ethylenediamine, N-(2-hydroxyethyl)ethylenediamine, and 1,4,7,10-tetraazacyclododecane decreased rates of CuII-facilitated conversion, while 1,5,9-triazacyclododecane actually increased rates of conversion. H NMR and UV spectroscopy provide evidence for the formation of 1:1 CuII-daminozide complexes. Halide ion effects and nitrogen-donor ligand effects point to an oxidative mechanism for CuII-facilitated daminozide breakdown, rather than hydrolysis. The structurally related compound butyric acid 2,2-dimethylhydrazide (BH) is subject to the same CuII-facilitated breakdown via an oxidative mechanism. N,N-Dimethylsuccinamic acid (SA), in contrast, breaks down via a hydrolytic mechanism.     

Co-transport of metal complexes by the green mussel Perna viridis

We examined the uptake of ligand-bound metals (Cd and Zn) by the green mussel Perna viridis using defined artificial seawater. Different free ion concentrations (1 pM to 10 microM) in uptake solutions were created by adding different amounts of total metals (Cd 0.1 nM to 0.1 mM; Zn 0.5 nM to 0.05 mM) and ligands (EDTA, NTA, citric acid). Our results showed that Cd and Zn uptake could not be fully explained by the free Cd and Zn concentrations in the presence of different ligands, indicating that metal-ligand complexes were at least partially available for uptake by the mussels. Total Zn concentrations appeared to be a better predictor of metal uptake than the free Zn ion concentrations in the presence of different ligands. Uptake of lipophilic organic metal complexes was substantially greater than the hydrophilic metal complexes, even though the free ion concentration was comparable or lower. Moreover, the radiolabeled ligand compounds were directly accumulated by the mussels. The accumulation of metal complexes may explain the increased metal uptake with increasing ligand and total metal concentration, even though the free ion metal concentration was constant. Overall, our experimental results indicated that free metal ion cannot fully explain metal uptake since metal complex species were also available to the mussels to some extent, apparently through a co-transport process.     

Labile Cd complexes increase Cd availability to plants

Dissolved trace metals are present in the environment as free ions and as complexes. Commonly used models to predict metal bioavailability consider the free ion as the major bioavailable species. However, increases in metal availability in the presence of metal complexes have repeatedly been found. We measured the uptake of cadmium (Cd) by spinach (Spinacia oleracea) from solution in absence or presence of synthetic ligands. At the same free ion concentration, the uptake of Cd ranged over almost 3 orders of magnitude and was largest in treatments with fast dissociating (i.e. labile) complexes. Similar results were found for the diffusional fluxes in these solutions, as measured with the DGT technique. The observed effect of Cd complexes on the plant uptake was in agreement with model calculations in which plant uptake was assumed to be governed by the diffusional flux. These results strongly suggest that Cd uptake is rate-limited by diffusion of the free ion to the root surface, even in stirred solutions. As a result, dissolved Cd complexes can increase Cd uptake, resulting in apparent exceptions from the free ion activity model. The magnitude of this increase depends both on the concentration and on the lability of the complexes. The free ion concept should therefore be reconsidered when transport limitations of the metal ion to the uptake site prevail.     

Synthesizes and Characterization Studies of Some Metal Ion Complexes with EOSBE and MOSBE

This work includes synthesis of 2,2＇-（5,5＇-（ethane-1,2-diyl）bis（1,3,4-oxadiazole-5,2diyl））bis（sulfanediyl）dibenzenamine （EOSBE） and 2,2＇-（5,5＇-methylenebis（1,3,4-oxadiazole-5,2-diyl）bis（sulfanediyl））dibenzenamine （MOSBE）. All synthesized ligands were characterized by IR, ^1H-NMR, ^13C-NMR, UV-visible spectroscopies and molar conductivity. A series of complexes with a general formula [M2LCl4]. Where M（Ⅱ） = Co, Ni, Cu and Zn; L = EOSBE and MOSBE were synthesized in basic media using KOH solution. In these complexes both ligands are bidentate ligands coordinated through sulfur and nitrogen. All complexes have been characterized by IR-spectra, UV-visiblc spectra, conductivity and magnetic susceptibility.     

胶原水解度的测定

研究了一种新的制革废弃胶原水解程度的定量评价方法,即分别测定胶原在水解反应中断裂的肽键数和胶原中的总肽键数,通过计算两者间的比值得到胶原的水解度。试验结果表明:采用该方法可以准确、直观地表征胶原的水解程度;与茚三酮比色法相比,甲醛滴定法能够更准确地测定胶原水解产物中的氨基含量,因此更适合用于胶原水解度的测定。     

Zr^4＋离子在皮革染色中的应用

本文研究了金属离子Zr^4 与皮革染色常用黑色染料的作用机理。染料的活性基团、皮胶原纤维活性基团金属离子Zr^4 能够形成混合络合物，可以提高染料的耐摩擦坚牢度。     

Mechanism of interactions between Hg(II) and Demeton S: an NMR study

The chemical fate of organophosphorus pesticides (OPs) has been proven to depend strongly on the chemistry of their aquatic environment. In particular, metal ions (and metal oxide surfaces) have been known to play an important role in the hydrolytic fate of OPs. Various postulates regarding the mechanism of metal-ion-promoted hydrolysis of OPs have been made over the years. However, direct spectroscopic evidence to pinpoint the hydrolytic products and the exact interaction between metal ions and organophosphorus pesticides are still lacking. We report herein the first in-situ study of the interaction between an aqueous solution of Hg(II) and Demeton S using 1H- and 31P NMR spectroscopy. It was found that the interactions between Hg(II), a soft Lewis acid, and Demeton S tend to be a strong function of the aqueous speciation of Hg(II), and the bonding between Hg2+ and Demeton S does not involve the central P=O bond but rather Hg2+ bonds with the two sulfur atoms in the Demeton S side chain and subsequently stabilizes the Demeton S molecule, a phenomenon not previously reported for any metal ion-OP systems studied. On the basis of this study, generalizations regarding the nature of metal ion binding even within a given class of OPs (i.e., phosphorodithioates, phosphorothioates, phosphorothiolates, etc.) should be avoided or only made with extreme caution.     

甘氨酸及其小肽配合物的pH电位法研究

利用ｐＨ 电位法研究了甘氨酸及其二、三肽与锌、铜元素的配位作用,测定了相应的配合稳定常数,结果表明,氨基酸和二、三肽的配合行为不同,而小肽之间配位作用基本相似．ｐＨ 电位法研究还表明,铜与肽的配合过程中存在着明显的晶体场稳定化能效应,表现在配合滴定过程中出现特征颜色变化（双缩脲反应）．     

Interaction of copper ion with some food dyes.

The nature of the complexes formed by Cu²⁺ with some food dyes has been studied spectrophotometrically under varied conditions. The results indicated formation of 1:1 metal: dye species at pH 4.5 and of 2:1 metal: dye species at higher pH. The latter result is unexpected and surprising since in most cases azo dyes form 1:1 or 1:2 metal: dye species and no example of a metal complex having more than one metal atom per dye molecule has so far been reported. This curious observation has been rationalised in terms of a salt forming Cu²⁺ ion and a coordinated Cu²⁺ ion per dye molecule; tentative structures for these species have also been proposed. It is hoped this novel finding will stimulate further investigations into the metal-dye complexes.     

Does caffeine bind to metal ions?

The complex formation capacity of caffeine, a highly-consumed tea and coffee component, was determined for Ca, Mg, Fe, Zn, Pb, Mn, Co and Cr metal ions. The binding constants of metal ion–caffeine complexes for the metals chosen were determined spectrophotometrically. The results were compared with the known stability constants of metal ion–EDTA complexes, EDTA being known for its high metal binding capacity. Furthermore, iron chelating activity of caffeine, using the ferrozine reference method, was studied and compared with that of EDTA. The results showed very little complex formation capacity of caffeine with binding constants of 29.6, 22.4, 59, 396, 55, 9.3, 83 and 592 M⁻¹ for Ca, Mg, Fe, Zn, Pb, Mn, Co and Cr metal ions, respectively, in contrast to that of EDTA. The iron chelating activity of caffeine was also found to be 6%, which was considered to be quite low compared with EDTA.