锰(Ⅱ)、钴(Ⅱ)、铜(Ⅱ)和镉(Ⅱ)与吡哆醇配合物的结构研究

本文合成了吡哆醇与锰(Ⅱ)、钴(Ⅱ)、铜(Ⅱ)和镉(Ⅱ)的配合物。通过元素分析确定了配合物的组成。通达摩尔电导、比移值,紫外光谱、红外光谱和核磁共振谱的测定和分析,推断了配合物的结构。     

HYDROFORMYLATION OF 1-HEPTENE CATALYZED BY RUTHENIUM CLUSTERS

Hydroformylalion of 1-heptene catalyzed by homogeneous and heterogeneous Ru3(CO)12 catalyst has been investigated. Ru3(CO)12 almost has no activity when the reaction temperature is below 60℃, and nearly stable activity when over 100℃. The maximum selectivity for aldehyde is obtained at 120℃ and V/I values of aldehyde and alcohol decrease rapidly with increasing temperature. Supported Ru3(CO)12 catalysts modified with NaBH4 or KOH have higher activity and selectivity for aldehyde. Compared with supported Ru3(CO)12 catalysis, Ru3(CO)12/Co2(CO)g/γ-Al2O3 has high activity and selectivity. When PPh3 or (NKt4)Cl is added to the reaction system, the selectivity for aldehyde and the .N/I ratio increase. The FT-IR spectra of catalysts alter reaction show that Ru3(CO)12 is transformed to a hydrocarbonyl complex [HRu3(CO)11]-, and (NEt4)Cl promotes the formation of |HRu3(CO)11|- and stabilizes it.     

Na~+/Ca~(2+) Exchange-mediated La~(3+) Entry in Human Lymphocytes

With extensive applications the rare earth elements to agriculture, medicine and animal husbandry, whether rare earth ions can cross cell membranes and participate in the metabolism of animals and plants is not clear until now. Otherwise, rare earth ions have different interaction fashions to different kinds of cells, therefore, in this study we determined whether La3+ enter human peripheral blood lymphocytes via Na+/Ca2+ exchanger (measured with fura-2).Relative sensitivity of fura-2 to Ca2+…     

Spectroscopic Study of the Interaction of Bu_2SnCl_2 with EHPG

A number of Sn (Ⅳ)complexes have been synthesized since 1980 and tested its anticancer activity1. The simplest complex Bu2SnCl2 has activity to P388 tumor cells. Several metal complexes such as Ru-ind (trans-indazolium (bisindazole) tetrachloro- ruthenate (Ⅲ)) had used transferrin as a drug delivery system, the complexes still exhibit high antitumor activity and lower toxicity2. We use EHPG as a model ligand3 to study the interaction between Bu2SnCl2 and EHPG. EHPGAt first, we stud…     

Cleavage of DNA by a New Mixed-ligand Cu（ Ⅱ ） Complex

Cleavage of DNA pUC19 by [Cu(saldien)(NH3)]C12 (here, saldien=bis(salicylicdene)-diethylenetriamine) was investigated at different pHs, times, concentrations, and 37℃. It wasfound that the copper( Ⅱ ) complex could cleave DNA without added coreactants.     

Synthesis and DNA Cleavage Studies of 2,6-Dimethoxyhydroquinone-3-Mercaptoacetic Acid Conjugates

In previous paper and work, we reported the synthesis and cytotoxicity studies of a novel series of short chain peptide conjugates of the cytotoxic agent 2, 6-dimethoxyhydro -quinone-3-mercaptoacetic acid1 (DMQ-MA). The DMQ-MA is a derivative of 2,6-dimethoxybenzoquinone, which is a natural product of fermented wheat germ and found to have a wide spectrum of cytotoxicity against various tumor cell lines under the synergistic activation of L-ascorbic acid (AH2)2,3. Compared with DMQ, DMQ…     

Efficient Cleavage of DNA by the Novel Copper (II) Complex Derived From 2,2'-Pyridil Ligand

Due to the importance of oxidative degradation of nucleic acids in mutagenesis, carcinogenesis, and aging, a large number of chemical and biological investigations have been recently published1. Artificial metallonucleases have been proven to be efficient tools for the footprinting and sequence-specific targeting of nucleic acids1,2. They usually require high concentrations of the complex and of an external reducing agent (such as dithiothreitol, DTT) to form a reactive species in situ, the f…     

Molecular modeling of the binding mode of chiral metal complexes A- and A-[Co(phen)_2dppz]~(3 ) with B-DNA

Molecular modeling methods have been applied to the structural characterization of the interaction between chiral metal complexes [Co(phen)2dppz]3 (where phen = 1, 10-phenanthroline, dppz = dipyrido[3,2-a: 2', 3'-c]phenazine) and the oligonucleotide (B-DNA fragment). The natures of two kinds of the binding modes, which are currently intense controversy, have been explored. Barton proposed that there is enantio-selective DMA binding by the octahedral complexes and intercalative access by these complexes from the major groove; but Norden suggested that both enantiomers bind extremely strongly to DNA from the minor groove without any noticeable enantio-selectivity. Our results support and extend structural models based upon Norden's studies, and conflict with Barton's model.     

咖啡酸及其衍生物光谱特性研究

研究了不同pH值条件下 ,咖啡酸类化合物溶液的荧光及紫外光谱特性。实验结果表明 :咖啡酸类化合物有很宽的pH发光范围 (2～ 1 2 ) ,发光强度、光谱形状及峰位随pH值不同而异 ,且在pH =9～ 1 0时 ,咖啡酸类化合物荧光强度最强。研究还发现 :咖啡酸类化合物 4 位酚羟基的解离可导致荧光强度显著增强 ,而 3 位酚羟基的解离可能会导致荧光猝灭 ,并且在强酸和强碱介质中发射荧光均被显著猝灭 ;此外 ,在强碱性介质中紫外光谱形状有很大变化 ,表明咖啡酸类化合物在强碱性下分子结构发生了明显改变。     

活性炭富集ICP-AES法测定铜精矿中微量金

采用ICP-AES法对铜精矿中微量金进行了测定。样品首次采用灼烧,酸分解,活性炭吸附富集等步骤进行了预处理。结果表明,该方法的检出限为0.028μg·mL-1。相对标准偏差(RSD)小于2％。该方法简便,可靠,准确。