轻稀土B-15-C-5联吡啶三元配合物

合成了稀土(Ln=La—Eu)硝酸盐与苯并-15-冠-5和2,2’-联吡啶的三元配合物,并培养出La-配合物的单晶,测定了的分子结构和晶体结构。经元素分析确定其化学组成为Ln(NO_3)_3·bipy·2H_2O·B-15-C-5。晶体属单斜晶系,空间群为P2_1/n。晶胞参数:a=11.951(6),b=18.181(7),c=14.754(5);β=96.19(3)°;V=3187.0,Z=4,D_c=1.637g/cm~3。最后偏离因子R=0.035。     

Synthesis of a novel rigid molecule family for the investigation of electron and energy transfer

Three new rigid bridging ligands for metal complexation (7=bmb, 8=bqb and 11=btb) were prepared from a rigid triptycene spacer connected to two bipyridine ligands using a Horner–Emmons type reaction. The triptycene spacer is substituted by methoxy groups in the case of bmb and in the case of bqb by a benzoquinone substituent. The corresponding metal complexes (ruthenium and/or osmium) were synthesised and the different luminescence behaviour was tested. They show great potential for the investigation of intramolecular electron and energy transfer reactions. The dinuclear metal complex Ru---bqb---Os is an interesting system in which the bridging ligand bqb acts as a redox switch, able to tune the conductivity for energy or electrons across the bridge.     

钴(II)-联吡啶-α-氨基酸的热力学和动力学研究

关于联吡啶为第一配体的二元、三元配合物的热力学和动力学性质的研究,以铜（Ⅱ）作为中心离子最为多见,而以钴（Ⅱ）作为中心离子的报导较少．实验表明,过渡金属钻（Ⅱ）能与大多数的生物配体、大π共轭体系形成相当稳定的二元、三元配合物,是生物功能模拟的一个具有应用价值的中心离子·钴（Ⅱ）卟啉可以代替铁（Ⅱ）卟啉,模拟血红蛋白、肌红蛋白[1],在生物体内起到输送氧的作用．为了充分了解钴（Ⅱ）与生物配体的配伍能力、配位方式以及其配位过程的动态行为,为推动钴（Ⅱ）配合物及其生物功能的模拟研究,本文分别采用PH电位法…     

An anticancer metallobenzylmalonate: crystal structure and anticancer activity of a palladium complex of 2,2′-bipyridine and benzylmalonate

The novel metallobenzylmalonate [Pd(bipy)(bmal)]?·?2H₂O (bipy?=?2,2′-bipyridyl, bmal?= benzylmalonate) has been synthesized and structurally characterized by element analyses, electronic spectroscopy, electrophoresis and single-crystal X-ray diffraction. The complex is orthorhombic, space group Pna2₁, with a?=?7.637(2), b?=?13.018(4), c?=?20.961(7)?Å, V?=?2083.8(12)?ų, Z?=?4. Pd(1) is four coordinated by two nitrogen atoms from the bipy ligand and two oxygen atoms from bmal with square planar geometry. In the lattice, π–π stacking and hydrogen bonding are the main intermolecular interactions and propitious for non-covalent insertion into DNA molecules. Electronic spectra confirm that the main reaction mode of the compound with DNA is non-covalent. Electrophoresis shows the cleavage of both supercoiled and circular DNA to form small molecular fragments under the action of the complex. The complex shows excellent anti-cancer activity towards lung cancer AGZY-83a.     

Synthesis,Crystal Structure and Properties of a 4,4′-Bipyridine Bridged Trigonal-Bipyramidal Copper Homobinuclear Complex with Tris(2-Aminoethyl)amine

The synthesis of the binuclear complex [(tren)Cu(4,4'-bipy)Cu(tren)] (ClO₄)₄ where tren = tris(2-aminoethyl) amine and 4,4'-bipy = 4,4'-bipyridine, is described. Single-crystal X-ray diffraction study of the homobinuclear complex shows that two copper(II) ions are bridged by 4,4'-bipyridine and each copper(II) ion is trigonal-bipyramidally coordinated, with tren occupying four sites [Cu-N = 2.030(2), 2.047(2), 2.078(2), and 2.119(2) Å respectively] and a bridging 4,4'-bipyridine in the apical position. The Cu-Cu distance is 11.11 Å. In variable-temperature ESR spectra, the presence of hyperfine structure suggest that some interaction exists between the two copper(II) ions. Temperature-dependent susceptibility studies indicate that it is a weak ferromagnetic interaction with 2J = 1.23 cm^-1.     

[Ru(bipy)(CN)4] and its derivatives: Photophysical properties and its use in photoactive supramolecular assemblies

This review describes the intriguing properties of the complex anion [Ru(bipy)(CN)₄]²⁻, whose redox and photophysical properties are strongly solvent-dependent. This complex and its analogues and derivatives are proving to be of particular value as components of polynuclear assemblies because of the ease with which they associate with other species by either hydrogen-bonding via the cyanides, or by direct ligation of the cyanide ligands to other metal ions. The strong solvatochromism means that the ability of the complex to act as an energy or electron donor in its ³MLCT excited state can be switched over a wide range, a feature which has so far only been exploited in a few instances.     

Chiral eighteen-component three-dimensional supramolecular entities stabilized by the hydrogen bonding and coordination interactions

A new class of chiral eighteen-component three-dimensional supramolecular entities has been assembled in toluene and chloroform from twelve zinc porphyrin-appended 2-(ethylamino)- pyrimido[4,5-b][1,8]naphthyridin-4(3H)-one monomers and six chiral bipyridyl compounds. The heterocyclic segments form two C₆-symmetric cyclic hexamers, which are stabilized by a well-established DDA-AAD hydrogen bonding motif, while the six chiral bispyridine ligands are coordinated to the corresponding zinc porphyrin units to give the two-layered architectures. The structures have been characterized by the ¹H NMR, UV-vis and circular dichroism experiments, which also reveals that, when the concentration of the monomers is high enough, the chiral supramolecular entity can be formed exclusively.     

Kinetic and Spectrophotometric Determination of Thioctic Acid in Bulk and Pharmaceutical Formulations

Three simple and sensitive spectrophotometric methods were developed for the determination of thioctic acid in bulk and in its pharmaceutical preparations using iron(III) as an oxidizing agent. Method A is based on kinetic investigation of oxidation reaction of the drug with iron(III) and a subsequent chelation of the produced iron(II) with ferricyanide to form prussian blue colored product at room temperature for a fixed time of 15 minutes at 750 nm. Methods B and C are based on oxidation of the studied drug with iron(III). The equivalent iron(II) produced is allowed to react with either o‐phenanthroline or bipyridyl to give colored species measurable at 510, 522 nm, respectively. Regression analysis of Beer‐Lambert plots showed a good correlation in the concentration ranges of 0.4–4 μg/mL with a detection limit of 0.095 μg/mL for method A and 0.5–5 μg/mL with detection limits 0.137 and 0.127 for method B and C, respectively. The three methods were successfully applied for the determination of the drug in its dosage forms. The percentage recoveries were 99.88 ± 1.40, 99.98 ± 1.26 and 100.64 ± 1.07, respectively.     

Cadmium(II) Complexes with Mixed cis‐Epoxysuccinate and 2,2′‐Bipyridyl‐Like Ligands: Syntheses,Crystal Structures,and Luminescent Properties

Two new Cd^II complexes, [Cd( ces )(phen)]_∞ ( 1 ) and {[Cd( ces )(bpy)(H₂O)](H₂O)}₂ ( 2 ), were prepared by slow solvent evaporation methods from mixtures of cis‐epoxysuccinic acid and Cd(ClO₄)₂ · 6H₂O in the presence of phen or bpy co‐ligand ( ces = cis‐epoxysuccinate, phen = 1,10‐phenanthroline, and bpy = 2,2′‐bipyridine). Single‐crystal X‐ray diffraction analyses show that complex 1 has a one‐dimensional (1D) helical chain that is further assembled into a two‐dimensional (2D) sheet, and then an overall three‐dimensional (3D) network by the interchain C–H ··· O hydrogen bonds. Complex 2 features a dinuclear structure, which is further interlinked into a 3D supramolecular network by the co‐effects of intermolecular C–H ··· O and C–H ··· π hydrogen bonds as well as π ··· π stacking interactions. The structural differences between 1 and 2 are attributable to the intervention of different 2,2′‐bipyridyl‐like co‐ligands. Moreover, 1 and 2 exhibit intense solid‐state luminescence at room temperature, which mainly originates from the intraligand π→π* transitions of aromatic co‐ligands.     

Syntheses and structural characterization of two new nanostructured Bi(III) supramolecular polymers via sonochemical method

Two new bismuth(III) coordination supramolecular polymers, {[Bi₂(Hbpp)(bpp)(μ-I)₂I₆](Hbpp)·MeOH}_n (1) and [Bi(Hbpp)(Br₄)] (2), (bpp = 1,3-di(pyridin-4-yl)propane) were prepared and were structurally characterized by single crystal X-ray diffraction. Single crystalline one-dimensional materials were prepared using a heat gradient applied a solution of the reagents using the branched tube method. The structural determination by single crystal X-ray crystallography shows that compounds 1 and 2 form monoclinic polymers with symmetry space group P2₁ in the solid state. These new nanostructured Bi(III) supramolecular compounds, {[Bi₂(Hbpp)(bpp)(μ-I)₂I₆](Hbpp)·MeOH} (1) and [Bi(Hbpp)(Br₄)] (2), were also synthesized by sonochemical method. The nanostructures were characterized by Field Emission-scanning electron microscopy (FE-SEM), powder X-ray diffraction (PXRD) and IR spectroscopy.