脲基苯乙炔4-′(对甲基苯基)-6-苯基-2,2′-二联吡啶铂(II)络合物的合成

本文通过异氰酸酰化反应合成了含有脲基的苯乙炔新型配体及以它作为辅助配体的4′-(对甲基苯基)-6-苯基-2,2′-二联吡啶铂(II)络合物,初步研究了铂(II)络合物的光物理性质,发现由于脲基的存在,当浓度大于3.32×10-5mol/L时铂(II)络合物能够发生分子间簇集.     

Spectral studies of bridged bisindenylmetallocenes and products of their reactions with polymethylalumoxane in toluene and dichloromethane in the visible region

Quantitative characteristics of changes in the energy of charge transfer from -bonded ligands to metal are presented for the series of structurally similar ansa-metallocene complexes of IVB Group elements. The changes are caused by the solvation effect, replacement of -bonded chlorine ligands by methyl groups and of bridging ethylene groups by dimethylsilylene moieties, introduction of the methyl substituent into position 2 and phenyl substituent into position 4 of the indenyl system, variation of the transition metal in metallocene, and formation of complexes with polymethylalumoxane (MAO) at different Al_MAO/Zr ratios. These effects are found to be additive.     

Molecular modeling study of the differential ligand–receptor interaction at the μ, δ and κ opioid receptors

3D models of the opioid receptors , and were constructed using BUNDLE, an in-house program to build de novo models of G-protein coupled receptors at the atomic level. Once the three opioid receptors were constructed and before any energy refinement, models were assessed for their compatibility with the results available from point-site mutations carried out on these receptors. In a subsequent step, three selective antagonists to each of three receptors (naltrindole, naltrexone and nor-binaltorphamine) were docked onto each of the three receptors and subsequently energy minimized. The nine resulting complexes were checked for their ability to explain known results of structure-activity studies. Once the models were validated, analysis of the distances between different residues of the receptors and the ligands were computed. This analysis permitted us to identify key residues tentatively involved in direct interaction with the ligand.     

Synthesis and Crystal Structure of 1,4-Bis(2-hydroxymethylphenyl)-1,4-dioxabutane

1 INTRODUCTION Macrocyclic ligands and their metal complexes have received much attention due to their applications in ion transport, ion separation and as models in biomimic researches[1~7]. The synthetic methods of macrocyclic ligands and their metal complexes are mainly divided into three kinds[8]. The first one is synthesizing free ligand, then forming the metal complexes; the second is template synthesis; and the third is synthesizing the end-off or side-off precursor ligand, then c…     

若干中性配体对Mo—Fe—S簇合物自兜的影响

通过电子吸收光谱的变化研究了一些含N和含P中性配体对MoS_4~(2-)-nFeCl_2-DMF体系形成立方烷型Mo-Fe-S簇合物的可能影响。     

苯二甲酰基桥联铁硫配合物［（μ－RS）Fe_2（CO）_6］_2（μ－OCC_6

通过由Ｆｅ３（ＣＯ）１２、ＲＳＨ和Ｅｔ３Ｎ所形成的［（μ－ＣＯ）（μ－ＲＳ）Ｆｅ２（ＣＯ）６］Ｅｔ３ＮＨ于室温下分别与对或间苯二甲酰氯的原位反应，首次合成６个结构新颖的苯二甲酰基桥联铁硫配合物［（μ－ＲＳ）·Ｆｅ２（ＣＯ）６］２（μ－ｐ－ＯＣＣ６Ｈ４ＣＯ－ｐ－μ）（Ｒ＝Ｅｔ，ｎ－Ｂｕ，ｔ－Ｂｕ）以及［（μ－ＲＳ）Ｆｅ２（ＣＯ）６］２（μ－ｍ－ＯＣＣ６Ｈ４ＣＯ－ｍ－μ）（Ｒ＝ｎ－Ｐｒ，ｎ－Ｂｕ，ｔ－Ｂｕ）。经元素分析、ＩＲ光谱及１ＨＮＭＲ表征了它们的结构，并讨论了产物的生成过程。此外，还提出了合成对苯二甲酰氯的一种新方法。     

Kinetic studies of nickel speciation in model solutions of a well-characterized humic acid using the competing ligand exchange method

Publications on the binding characteristics of metals with humic acid (HA) are sparse. Here we investigated the release of nickel from Ni(II)-HA complexes using model solutions of three different [Ni(II)]/[HA] mole ratios at three different pH values; we also compared the results with those of [Ni(II)]/[FA] complexes from previous work in this laboratory. Ligand exchange kinetics using the competing ligand exchange method (CLEM) were studied using two different techniques: graphite furnace atomic absorption spectrometry (GFAAS) with Chelex 100 resin as the competing ligand, and adsorptive cathodic stripping voltammetry (AdCSV) with dimethylglyoxime as the competing ligand to measure the rate of dissociation of Ni(II)-HA complexes. The results of the kinetic studies showed that as the [Ni(II)]/[HA] mole ratio was decreased, the rate of dissociation of Ni(II)-HA complexes decreased, and the proportion of free Ni²⁺ ions plus very labile nickel complexes decreased while the proportion of the less labile kinetically distinguishable components increased. Generally, the rate of dissociation of Ni(II)-HA complexes was slower than that of Ni(II)-FA complexes. Studies on the validity of the kinetic model showed that the concentrations of chemical species varied in a reasonable way with pH and the [Ni(II)]/[HA] mole ratios, indicating that the kinetically distinguishable components have chemical significance and the kinetic model is valid.     

Synthesis and Crystal Structure of a New 2D Honeycomb-like Cadmium(II) Complex with Tripodal Ligand

ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｅｐａｓｔｓｅｖｅｒａｌｙｅａｒｓ ,ｃｏｎｓｉｄｅｒａｂｌｅｐｒｏｇｒｅｓｓｈａｓｂｅｅｎａｃｈｉｅｖｅｄｉｎｃｏｎｔｒｏｌｌｉｎｇｔｈｅａｓｓｅｍｂｌｙｏｆｉｎｄｉｖｉｄｕａｌｂｕｉｌｄｉｎｇｂｌｏｃｋｓｉｎｔｏｓｔｒｕｃｔｕｒｅｓｗｉｔｈｓｐｅｃｉｆｉｃｔｏｐｏｌｏｇｉｅｓａｎｄｉｎｔｅｒｅｓｔｉｎｇｐｒｏｐｅｒｔｉｅｓｓｕｃｈａｓｍｏｌｅｃｕｌａｒｒｅｃｏｇｎｉｔｉｏｎ ,ｉｏｎｅｘｃｈａｎｇｅａｎｄｓｅｌｅｃｔｉｖｅｇｕｅｓｔｉｎｃｌｕｓｉｏｎ .1 3 Ｉｔｉｓ…     

Affinity Chromatography of Insulin with a Heptapeptide Ligand Selected from Phage Display Library

A heptapeptide phage display library was screened with insulin to find its ligands for affinity chromatography. The peptide was synthesized and coupled to EAH Sepharose 4B (5.4 mol mL^–1 bed). Then, insulin chromatography was carried out with mobile phases of different pH values and by the addition of urea and ethylene glycol. It was found that electrostatic interactions were predominant for the affinity binding, and hydrogen bonding might also contribute somewhat to the affinity. Finally, frontal analysis was performed and the dynamic binding capacity of the affinity column for insulin at 50% breakthrough was estimated at 60.6 mg mL^–1 bed, which was about two times higher than the theoretical binding capacity of the monomeric insulin. The result suggests that insulin was bound in dimer state in a stoichiometric relationship with the coupled peptide, indicating the high binding efficiency of the peptide ligand for insulin.