Preparation of Platinum(II) Complexes with 1-β-D-Ribofuranosyl-1,2,4-triazole-3-carboxamide and its Deoxy-analogue

The platinum (II) complexes of the [Pt (N4,N7-Ribavirin) (DMSO) Cl], [Pt (N4,N7-De-oxyribavirin) (DMSO) Cl] were obtained by the reactions of cis-[Pt (DMSO)2 Cl2] and K[Pt (DMSO) Cl3] with 1-??-D-ribofuranosyl-1,2,4-triazole-3-carboxamide (Ribavirin) and its deoxy-analogue (deoxyribavirin). The preparation of 1-(2'-deoxy-?-D-ribofuranosyl) -1,2,4-triazole-3-carboxamide was also performed through a four-step procedure, protection of 3', 5'-dihydroxyl group of Ribavirin with 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane (TPDS-Cl), phenoxythio-carbonylation of the 2'-hydroxyl group of 3', 5'-O-TPDS-Ribavirin with phenoxythiocarbonyl-chloride (PTC-Cl), reduction of 2′-O-phenoxythiocarbonyl ester of 3', 5'-O-TPDS-Ribavirin with tri-n-butyltin hydride and AIBN, deprotection of 3', 5'-O-TPDS-Ribavirin with tetrabutylammon-ium fluoride in THF.

THE CHIRAL SELECTIVITY IN ACROSS－MEMBRANE TRANSPORT OF 1，2－DIAMINOCYCLOHEXANE PLATINUM（II）COMPLEXES AND THE CONTRIBUTION OF LEAVING GROUPS

The uptake kinetics of platinum(II)complexes of 1,2 -diaminocyclohexane(dach)isomers(1R,2R-dach, 1R,2S-dach. 1S,2S-dach) with various leaving groups, Chloride(CI), oxalate (OX),squaric acid(SA), and demethylcantharic acid (DA) was studied in the plasma isotonic buffer. The experimentalresults show that across-membrane transport of all the platinum complexes studied follows a firstorder Kinetic process and a passive diffustion mechanism. The uptake rate constants of these platinum(II)complexes decrease in the following sequence with the k value(h-1):CI>SA>OX>DA. It isnoteworthy that the k values of the platinum(II)complexes with same leaving group reduce as: 1R,2R-dach>1R,2S-dach>1S,2S-dach. Based on these results, it is firstly suggested that the erythocytemembrane recognizes the chirality of these platinum complexes.

In vitro antitumor activity and targeted sites of two novel platinum-based(II) complexes on SW620 colon cancer cell line

Objective:The aim of our study was to evaluate the in vitro antitumor activity of two novel platinum-based(II) complexes(2.3-pyridinedicarboxylic acid dehydrate platinum and 2.3-pyrazinedicarboxylic acid dehydrate platinum),which were concurrently provided with hydrophilic carboxyl group and lipophilic pyrazinyl or pyridyl group,on SW620 colorectal cancer cell line and the impact of the two compounds on the cell cycle and apoptosis of the cells when compared with the oxaliplatin,desiring the new ligand combined with hydrophilic and lipophilic properties would facilitate the transportation and transmembrane of the drugs,showing a better antitumor activity.Methods:After SW620 cells were treated with different doses of the three platinum-based agents for 24,48 and 72 h,the cell proliferation inhibition rate was determined using methyl thiazolyl tetrazolium(MTT) assay;the morphology of cells were evaluated under inverted microscope;the changes in cell cycle were determined using flow cytometry;the percent apoptosis was measured using Annexin V/PI double staining and the micromorphology of the cells after drug exposure was evaluated using scanning electron microscopy.Results:The evaluation on the proliferation inhibition rate revealed that the three platinum-based agents inhibited the SW620 cells in a time-and dose-dependent manner and showed different strengths as pyridine > pyrazine > Oxa.Under optical microscope,the morphological changes such as cell shrinkage,round cells and dead cells were frequently observed after drug exposure.Cell cycle determination showed that all of the three agents could function to block the cells converting from phase S to phase G2M.Apoptosis evaluation revealed that the three agents promoted the apoptosis of SW620 cells in a time-and dose-dependent manner and showed different strengths as pyridine > pyrazine > Oxa.Typical early and late apoptotic morphological changes could be detected during electron microscopy.Conclusion:The two novel platinum-based(II) complexes showed a stronger antitumor effect on SW620 cells than oxaliplatin,with the targeted site at a certain phase of cell cycle and apoptosis.

Hexanuclear Complex of Platinum(II) with Cleavage Product of Cystamine Dihydrochloride by β-Mercaptoethylamine

Six-nuclear complexes of Platinum(II) with cleavage of a cystamine dihydrochloride by β-mercaptoethylamine with composition [Pt6(H2NCH2CH2S)8]Cl4·5H2O had been syntesized for the first time. Structure of the complex had been installed together with IKS- and XRD analysis. It has been established that each atom of platinum is surrounded by two atoms of sulfur and nitrogen due to bidentate coordination of a ligand. Only two of the six platinum atoms are on the same plane;other four atoms are in the different crossing planes. Four platinum atoms form adurable metal chelate cycles, which collapse over temperature 260℃. The results of IR spectroscopy confirmed with the RS-analysis.

Interactions Between Anticancer Pt(II) complexes and Human Erythrocyte Spectrin *

The interactions between human erythrocyte spectrin(SP) and Pt(II) complexes with different composition and configuration were studied by fluorescence and circular dichroism spectra. The results showed that there are 4.7×10 2 binding sites of cisplatin(CDDP) in a spectrin tetramer(SPT). Among them, about 70 sites with apparent binding constant K 1】3.47×10 6 were of highest affinity, 1.8×10 2 sites with K 2 = 3.47×10 6 were of high affinity, and other 2.2×10 2 sites with K 3 = 8.77×10 5 were of low affinity. The conformation change of spectrin, depending on the concentration of Pt(II) complex and molar ratio(R) of Pt(II) complex to spectrin, was induced by the binding of Pt(II) complexes. It indicated that the interaction of both CDDP and cis diaquodiamine platinum(DADP) with SP followed a two step first order kinetic process in the first stage (1 h), and the kinetic constants were determined. In the second stage, the induced conformation change, polymerization and depolymerization of SP were probably involved. It was noticed that in the reaction of SP and Pt(II) complexes with 1,2 cyclohexanediammine isomers as chiral carrier ligand, stereo matching played a more important role than the affinity of Pt(II) to thiol groups of SP.

Synthesis, Structure and Physical Properties of a Barium(II) Complex with 5-Sulfoisophthalic Acid Sodium

An alkaline earth metal-organic framework [Ba（Hsip）（H2O）4]n （1, NaH2sip = 5-sulfoisophthalic acid sodium） has been constructed, and characterized by single-crystal X-ray diffraction. In complex 1, each Ba（II） atom coordinates to one ligand Hsip3- and four water molecules with a distorted nine-coordinated monocapped tetragonal antiprism geometry. Each Hsip2- anion acts as a μ3-bridging ligand, in which two carboxylate groups adopt the same bidentate chelating coordinating model and the sulfonate group takes a monodentate coordinating model, resulting in a wave-like two-dimensional network with a （6, 3） topological structure. The two-dimensional networks are further linked by O–H···O to form a three-dimensional structure. Luminescent property and thermal stability of complex 1 are investigated. 1 belongs to the orthorhombic system, space group Pna21 with a = 7.3333（2）, b = 16.7044（3）, c = 10.4817（2）, Z = 4, V = 1283.99（5）3, Mr = 453.58, Dc = 2.346 g/cm3, F（000） = 880, μ = 3.314 mm–1, the final R = 0.0261 and wR = 0.0592 for 2425 observed reflections with I 2σ（I）.

Dioxygen Affinity and Catalytic Performance of Bis-(furaldehyde) Schiff Bases Co(II) Complexes in Cyclohexene Oxidation

Oxygenation constants and thermodynamic parameters DeltaH degrees and DeltaS degrees of cobalt (II) complexes with bis-(furaldehyde) Schiff bases (1, 2, 3, 4)were obtained by mearsuring saturated dioxygen uptake of these complexes in pyridine at different temperature. These complexes could activate molecular oxygen and were used as catalysts in cyclohexene oxidation. The influence of ligand structure on the dioxygen affinity and catalytic activity of the complexes were discussed.

Synthesis, Structure and Fluorescence of a Copper(II) Complex [Cu_2(bipy)_2(Hpht)_2Cl](Hpht)(bipy=2,2'-Bipyridine,H_2pht=o-Phthalic Acid)

The title complex [Cu2(bipy)2(Hpht)2Cl](Hpht) (bipy = 2,2?-bipyridine, H2pht = o-phthalic acid) has been synthesized in the NaOH aqueous solution of CuCl2, Gd(NO3)3, bipy and H2pht, and its crystal structure was determined by single-crystal X-ray diffraction method. It crys- tallizes in triclinic, space group P1, C44H31ClCu2N4O12, Mr = 970.26, a = 8.175(2), b = 16.254(4), c = 16.946(4) ?, α = 62.966(6), β = 84.833(8), γ = 84.348(8)°, V = 1993.4(8) ?3, Z = 2, Dc = 1.616 g/cm3, F(000) = 988 and μ = 1.207 mm-1. The final R = 0.0429 and wR = 0.0843 for 5682 observed reflections with I > 2σ(I). Each copper(II) atom displays a distorted square-pyramidal geometry with two nitrogen atoms of one chelate 2,2?-bipy molecule, two oxygen atoms from two different bridging carboxylate groups of Hpht- and one bridging chloride atom occupying the apical position. The two copper(II) atoms are connected by a μ2-Cl atom and two bridging Hpht- ligands in a syn-syn coordination mode to form an isolated dinuclear unit. The molecular structure is extended to a one-dimensional wavy chain through hydrogen bonds. The title complex exhibits blue fluorescent emission at 443 nm (λex = 372 nm) in the solid state at room temperature.

Synthesis and Crystal Structure of a Zinc(II) Complex with 2-(4′-Chlorine-benzoyl)-benzoic Acid and 1,10-Phenanthroline

A new metal-organic complex Zn2（cbba）4（phen）2 （Hcbba = 2-（4＇chlorine-ben- zoyl）benzoic acid, phen = 1,10-phenanthroline） 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, fluorescence spectrum and single-crystal X-ray diffraction. The compound crystallizes in orthorhombic, space group Pbcn with a = 12.0821（II）, b = 18.3140（17）, c = 30.961（3） A, V= 6850.7（11） A^3, C80H48C14N4O12Zn2, Mr= 1529.76, Dc = 1.483 g/cm^3,μ（MoKa） = 0.925 mm^-1, F（000） = 3120, Z = 4, the final R = 0.0559 and wR = 0.1146 for 3963 observed reflections （I〉 2σ（I））. In the crystal structure, the zinc atom is five-coordinated with three carboxylate oxygen atoms from three different cbba ligands and two nitrogen atoms from the phen ligand, showing a distorted square-pyramidal geometry. Furthermore, it exhibits a 3D supramolecular network through π-π interactions and shows yellow photoluminescent property at room temperature.

Synthesis, Crystal Structure and DNA Binding Studies of a Nickel(II) Complex with 2-Aminomethylbenzimidazole and Demethylcantharate

A new mixed-ligand nickel（Ⅱ） complex, [Ni（L）（DCA）（H2O）]·2H2O （L = C8H9N3, 2-aminomethyl-benzimidazole, DCA2- = 7-oxabicyclo[2,2,1]heptane-2,3-dicarboxylate, demethylcantharate, C8H8O5）, has been synthesized and characterized. The structure of the complex was determined by single-crystal X-ray diffraction. It is of monoclinic system, space group P21/c with a = 7.7211（7）, b = 12.0799（12）, c = 19.7867（19）, β = 100.390（6）°, V = 1815.2（3） nm3, Dc = 1.625 g·cm-3, Ζ = 4, F（000） = 928, R = 0.0314 and wR = 0.0822. In addition, the interaction between the complex and DNA was studied by means of fluorescence spectra and viscosity. The results indicate that the complex binds to DNA by the mode of partial intercalation with the Stern-Volmer constants Ksv of 3.81 × 104 mol·L-1.

Synthesis, Crystal Structure and Calculated β Value of a Tetrahedral Zinc (II) Complex——Zn(2-NH_2py)_2Br_2

A new zinc(II) complex, Zn(2-NH2py)2Br2 (py=pyridine), has been synthesized, and its molecular structure has been confirmed by IR, elemental analysis and -ray crystal structure analysis. Its space group is P21/n with Mr=413.43 (C10H12Br2N4Zn), a=7.435(2), b=12.865(3), c=14.186(4)? b=94.08(2)? V=1353.5(5) 3, Z=4, Dc=2.029 g/cm3, F(000)=328, ?2.378mm－1, R=0.0283, wR=0.0501. The total observed reflections with I≥2?I) were 5314, of which the independent reflections were 3106. The complex structure contains a distorted tetrahedron formed by four atoms coordinated to zinc atom, namely two bromide atoms and two nitrogen atoms. The two ZnBr bond lengths within one molecule, 2.3763(6) and 2.4002(5)? respectively, are not equal; and so are the two ZnN bond lengths, which are 2.031(2) and 2.044(2)?respectively. The calculation results using PM3 method through MOPAC software package in Chem 3D show that its first molecular hyperpolarizability b value is 5.210－30esu, which is comparable with that of p-nitroaniline. No bulk SHG effect has been detected due to the centrosymmetric space group.

Hydrothermal Synthesis, Crystal Structure and Photoluminescent Property of a Zinc(II) Complex with 2,2′-Diphenic Acid and 2,2′-Bipyridine Ligands

A new dinuclear complex [Zn（dpa）（bipy）（H2O）]2 （dpa = 2,2＇-diphenic acid, bipy = 2,2＇-bipyridine） 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, fluorescence spectrum and single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P21/c with a = 10.960（2）, b = 9.4841（18）, c = 20.599（4）, β = 104.452（3）o, V = 2073.4（7）3, C48H36N4O10Zn2, Mr = 959.55, Dc = 1.537 g/cm3, μ（MoKα） = 1.225 mm-1, F（000） = 984, Z = 2, the final R = 0.0364 and wR = 0.0843 for 2788 observed reflections （I 〉 2σ（I））. In the crystal structure, the zinc atom is five-coordinated with two carboxylate oxygen atoms from different dpas, one coordinated water molecule and two nitrogen atoms from bipy ligands, showing a slightly distorted triangular bipyramidal geometry. Furthermore, it exhibits a zero-dimensional network structure with a sixteen-membered ring and shows yellow photoluminescent property at room temperature.

Synthesis, Structure, and DNA Binding of a Platinum(Ⅱ) Complex Based on the 3,4,5-Trimethoxy-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline

A new platinum（Ⅱ） complex of [Pt（chda）（3,4,5-triopip）]Cl·2H2O（1） based on 3,4,5-trimethoxy-phenyl-1 H-imidazo[4,5-f][1,10]phenanthroline（3,4,5-triopip） has been synthesized by hydrothermal methods and its consequences are characterized by elemental analysis, IR, single-crystal X-ray diffraction, UV-Vis absorption and fluorescent spectrum. The UV-Vis absorption studies reveal that the molecule undergoes considerable interaction with the nucleic acid. In this mononuclear structure, the platinum adopts a four-coordinated square planar geometry, which may favor the intercalation between the neighboring bases of the G-quadruplex（G4） DNA.

Synthesis and photophysical and electrochemical properties of new cyclometalated platinum complex containing oxadiazole ligand

A new cyclometalated platinum complex containing 2, 5-bis(naphthalene-1-yl)-1,3,4-oxadiazole ligand was synthesized and characterized. The UV-Vis absorptions and photoluminescent properties of the ligand and its platinum complex were investigated. A characteristic metal-ligand charge transfer absorption peak at 439 nm in the UV spectrum and a strong emission peak at 625 nm in the photoluminescence spectrum were observed for this complex in dichloromethane. Cyclic voltammtry (CV) analysis shows that the EHOMO (energy level of the highest occupied molecular orbital) and ELUMO (energy level of the lowest unoccupied molecular orbital) of the platinum complex are about 、5.69 and 、3.25 eV, respectively, indicating that the oxadiazole-based platinum complex has a potential application in electrophosphorescent devices used as a red-emitting material.

Synthesis and Characterization of Chiral Mercury(II) and Cadmium(II) Complexes with 3,3'-Bipyridine-5,5',6,6'-tetramethyl-2,2'-dimethoxy-1,1'-biphenyl

Two homochiral mercury （1） and cadmium （2） complexes derived from chiral twisted biphenyl pyridine ligand （3,3＇-bipyridine-5,5＇,6,6＇-tetramethyl-2,2＇-dimethoxy-1,1＇-biphenyl） have been synthesized and characterized by IR, microanalysis, TGA, UV-Vis, powder and single-crystal X-ray crystallography. Both 1 and 2 crystallize in orthorhombic space group P21212 with Z = 2. For 1, a = 14.2038（16）, b = 14.3630（17）, c = 7.0257（8）, V = 1433.3（3）3, Mr = 878.91, Dc = 2.037 g/cm3, μ = 7.549 mm-1, F（000） = 824, the final GOF = 1.017, R = 0.0296 and wR = 0.0645 for 2925 observed reflections with I 2σ（I）. For 2, a = 14.212（3）, b = 14.392（3）, c = 7.0498（14）, V = 1442.0（5）3, Mr = 790.72, Dc = 1.821 g/cm3, μ = 2.924 mm–1, F（000） = 760, the final GOF = 1.075, R = 0.0340 and wR = 0.0834 for 3144 observed reflections with I 2σ（I）. The crystal structures of 1 and 2 are isostructural and each adopts a two-dimensional supramolecular network which contains the C–H···π interactions.

Silica-supported Polysiloxanes with Dithiacrown Ether Groups and Their Platinum Complexes

The present paper represents the syntheses of polypropyloxymethyldithia 15-crown-5 and 18-crown-6 supported on silica and their platinum complexes. The platinum complexes are effective catalysts for the hydrosilylation of olefins with triethoxysilane. The influences of temperature, amount of platinum complexes used and the nature of olefins used on the catalytic activity of the complexes are also investigated in this paper.

Synthesis and Crystal Structure of a Dinuclear Cu(II) Complex with Tridentate Schiff Base and Azido Bridge

A new dinuclear copper(II) complex ([Cu(C12H17N2O)(N3)]2, C24H34Cu2N10O2) has been synthesized and characterized by X-ray structure determination. It crystallizes in the monoclinic system, space group P21/c with a = 18.529(4), b = 10.933(2), c = 14.534(3) ?, β = 111.07(3)°, V = 2748(1) ?3, Z = 4, Mr = 621.69, F(000) = 1288, Dc = 1.503 g/cm3 and μ(MoKα) = 1.590 mm?1. The structure was refined to R = 0.0647 and wR = 0.1846 for 4406 observed reflections (I > 2σ(I)). The asymmetric unit comprises two halfmolecules. The complex is a centrosymmetric dimmer in which the copper atoms are penta-coordinated by three coordination atoms from the corresponding tridentate Schiff base ligand and two bridging azide anions. The Cu(II)…Cu(II) average distance is 3.350(1) ?.

Synthesis, Structure and Spectral Characterization of a Discrete Binuclear Copper (II) Complex

A discrete binuclear copper (II) complex containing Cu 2O 2 unit has been synthesized by the reaction of Cu (ClO 4) 2·6H 2O with 2 aminopyridine in the CH 3OH solution and characterized by X ray diffraction study and IR spectroscopy. The crystal is monoclinic, space group: P2 1/n, with unit cell parameters: a=8.2952(2), b=18.4633(3), c=10.5049(2) . β=108.965(1)°, V=1521.56(5) 3, Z=2, C 22 H 30 N 8O 10 Cl 2Cu 2, M r =764.52, D c =1.669 Mg/m 3, F(000)=780, μ (Mo Kα )=8.60, T =293(2)K, final R=0.0623, wR =0.1536 for 2660 observed reflections with I>2.0σ(I ). The centrosymmetric complex Cu 2(CH 3O) 2(C 5H 6N 2) 4(ClO 4) 2 comprises a pair of Cu(II) atoms bridged by two methanoxo and N coordination 2 aminopyridine. The Cu(II)…Cu(II) distance is 3\^002(1).

Synthesis and Structure of L-Aspartato- nickel(II) Complex with Benzimidazole

The title complex Ni(C4H5NO4)(C7H6N2)31.75(H2O) (C25H26.5N7NiO5.75, Mr = 575.74) has been prepared and its crystal structure was determined by X-ray diffraction method. The crystal of this chiral complex belongs to monoclinic, space group P21 with a = 13.208(1), b = 10.741(1), c = 19.398(1) ? b = 104.39(1)o, V = 2665.8(4) 3, Z = 4, Dc = 1.435 g/cm3, m(MoKa) = 0.780 mm-1 and F(000) = 1198. The final R = 0.0504 and wR = 0.1267 for 9159 observed reflections (I > 2s(I)), and R = 0.065 and wR = 0.1299 for 11006 independent reflections. The complex assumes a distorted octa- hedral coordinate geometry formed by one aspartate dianion and three benzimidazole ligands. The aspartate chelates to the Ni atom as a tridentate ligand. The lattice water molecules are hydrogen- bonded to the Ni complex molecule.

Synthesis and Crystal Structure of a New Nickel(II) Complex with Unsymmetric Quadridentate Schiff Base Containing Oxime

The title complex, C18H15N3NiO3, has been prepared and characterized by X-ray diffraction analysis. It crystallizes in the monoclinic system, space group Cc with a = 10.939(2), b = 22.909(5), c = 6.907(1) ?, β = 116.75(3)°, V = 1545.7(5) ?, Z = 4, Mr = 380.04, F(000) = 784, Dc = 1.633 g/cm3 and μ(MoKα) = 1.279 mm–1. The structure was refined to R = 0.0472 and wR = 0.0893 for 2571 observed reflections with I > 2σ(I). The absolute structure Flack parameter X is 0.01(2). In this crystal structure, strong face-to-face π-π stacking interactions between adjacent molecules lead to a one-dimensional chain structure.