Two Novel Nitrogen-rich Energetic Coordination Compounds M_2(DAT)_5(H_2O)_3(TNR)_2(M = Zn and Co):Synthesis,Characterization,Thermal Properties and Sensitivity

Two novel energetic coordination compounds Zn2（DAT）5（H2O）3（TNR）2 and Co2（DAT）5（H2O）3（TNR）2 were synthesized and their structures were characterized by elemental analysis and FT-IR spectroscopy.The crystal structures were determined by single-crystal X-ray diffraction.The results reveal that the compounds have similar molecular structures and the crystals belong to the triclinic system,space group P with a = 11.491（3）,b = 13.564（3）,c = 15.496（3） ,V = 2180.4（8） 3,C17H28 Zn2N36O19,Mr = 1203.02 g·mol-1,Dc = 1.832 g·cm-3,μ（MoKα） = 1.221 mm-1,F（000） = 1223,Z = 2,R = 0.0596 and wR = 0.1514 for 11289 observed reflections（I 〉 2σ（I）） for Zn2（DAT）5（H2O）3（TNR）2 and a = 11.5291（13）,b = 13.4894（15）,c = 15.4852（17） ,V = 2164.8（4） 3,C17H28Co2N36O19,Mr = 1190.14 g·mol-1,Dc = 1.826 g·cm-3,μ（MoKα） = 0.888 mm-1,F（000） = 1211,Z = 2,R = 0.0576 and wR = 0.1431 for 11218 observed reflections（I 〉 2σ（I）） for Co2（DAT）5（H2O）3（TNR）2,respectively.The thermal decomposition characteristics of the com-pounds were investigated using differential scanning calorimetry and thermal gravimetry-diffediffer-rential thermal gravimetry.The results of thermal decomposition processes were similar for the two compounds.Both undergo four-step decomposition after the loss of coordinated H2O molecules.The final solid residues for the two DAT complexes were the corresponding metal oxides.The kinetic parameter of the first exothermic process of the compounds was studied by applying the Kissinger and Ozawa-Doyle methods.The thermodynamic parameters of the activation could be calculated.Sensitivity tests revealed that Co2（DAT）5（H2O）3（TNR）2 was more sensitive than Zn2（DAT）5（H2O）3（TNR）2.

Syntheses, Crystal Structures, Magnetic and Luminescent Properties of Ni(Ⅱ), Cd(Ⅱ) and Pb(Ⅱ) Coordination Compounds Constructed from 5-Fluoronicotinic Acid

Five coordination compounds, namely [Ni2(5-Fnic)2(H2 O)4](1), [Ni(5-Fnic)(μ-5-Fnic)(H2 biim)]n(2), {[Cd((μ-5-Fnic)2(H2 O)2]×4,4’-bipy}n(3), [Pb2(μ-5-Fnic)2(μ3-5-Fnic)2(H2 O)2]n(4), and [Pb(5-Fnic)2(4,4’-bipy)(H2 O)](5), have been constructed hydrothermally using 5-FnicH(5-FnicH = 5-fluoronicotinic acid), H2 biim(H2 biim = 2,2’-biimidazole), 4,4’-bipy(4,4’-bipy = 4,4’-bipyridine), NiCl2×6 H2 O, CdCl2×H2 O and PbCl2. The products were isolated as stable crystalline solids and were characterized by IR spectra, elemental analyses, thermogravimetric analyses(TGA), and single-crystal X-ray diffraction analyses. Structures of 1~5 range from discrete 0 D monomers(1 and 5) to 1 D coordination polymers(2 and 4) and 2 D metal-organic network(3). A broad structural diversity of 1~5 is guided by the type of the metal(Ⅱ) node and the introduction of auxiliary ligands. The magnetic(for 2) and luminescent(for 3~5) properties were also investigated and discussed.

Syntheses, Crystal Structures and Luminescent and Magnetic Properties of Cerium(Ⅲ) and Zinc(Ⅱ) Coordination Compounds Constructed from 3,5-Dibromobenzoic Acid

Two coordination compounds, namely [Ce（3,5-Br2BC）3（3,5-HBrzBC）]n （1） and [Zn（3,5-Br2BC）2（phen）] （2, 3,5-HBr2BC = 3,5-dibromobenzoic acid, phen = 1,10-phenanthroline）, were assembled. Single-crystal X-ray diffraction studies show that compound 1 possesses a ID chain coordination network, which is further extended into a 3D supramolecular architecture via Br..＇Br and Br＇＂O halogen bonding. Compound 2 consists of a mononuclear molecule, which is assembled to a 3D supramolecular framework through C-H..-O hydrogen bond, π-π stacking interactions and Br..π halogen bonding. Luminescent and magnetic properties of both compounds have also been studied.

Ruthenium Coordination Compounds with Polypyridines Ⅶ． Non－intercalative Binding of Ru（Ⅱ） Complexes with Calf Thymus DNA

Two new ruthenium polypyridine complexes. L2RuL2+ where L=2,2'-bipyridine (bpy) and 2, 9-dimethyl-1. 10-phenanthroline (dmp); L' is Schiff base prepared from condensation of 4. 5 diazafluoren-9-one (AFO) and aniline. have been prepared and characterized by elemental analyses, electronic absorption, IR spectra. The binding of the complexes to calf thymus DNA has beeninvestics by absorption. emission spectra and circular dichroism spectroscopy. Experimental results show these two complexes bind to DNA by electrostatic mode and non-interactive binding mode.

STUDIES ON THE SOLID STATE REACTIONS OF COORDINATION COMPOUNDS： LXIX STEPWISE REACTION OF CuCl_2．2H_2O WITH 2，2＇－BIPYRIDYL

Consecutive reaction between two solids, CuCl2.2H2O and 2,2'-bipyridyl in 1:2 molar ratio proceed in tWo steps: the salt first converts to the mediate, then the mediate turns to the final product.

Syntheses of Coordination Compounds of (±)-2-Amino-3-(4-Hydroxyphenyl)Propionic Acid, Mixed Ligand Complexes and Their Biological Activities

Coordination compounds of (±)-2-amino-3-(4-hydroxyphenyl) propionic acid and their mixed ligand complexes with 1,10-phenantroline were synthesized, characterized using electronic and infrared spectral analyses and magnetic susceptibility. The compounds were evaluated for antimicrobial and antioxidant activities. Four different assays were applied for evaluating antioxidant capacity of the compounds. The results obtained indicated a diametric square planar geometry for both cobalt (±)-2-amino-3-(4-hydroxyphenyl) propionic acid complex and its mixed ligand complex. It was suggested that for the binary cobalt(II) complex, the phenolic substituent coordinated with neighbouring central metal ions. However, for the ternary cobalt(II) complex it was suggested it was deprotonated. Octahedral geometry was proposed for both copper complexes. Square planar geometry was indicated for the nickel?(±)-2-amino-3-(4-hydroxyphenyl) propionic acid complex and a mixture of square planar and octahedral geometry for the nickel mixed ligand complex. The cobalt mixed ligand complex elicited the highest activity for all the antioxidant assays. In most cases the binary complexes exhibited better antimicrobial activities relative to their ternary counterparts.

Synthesis Characterization and Biological Activities of an Enamine Derivative and Its Coordination Compounds

The medicinal uses and applications of metal complexes are of increasing clinical and commercial importance;this is as a result of some level of success achieved so far. In this regard, novel enamine free-base ligands were synthesized by the condensation of terephthalaldehyde and 2-(methylamino)ethanol. This afforded a dinegative ONNO donor enamine, free base, characterized using 1H and 13C NMR, Fourier-transformed infrared and UV-vis spectroscopy. Coordination compounds of the enamine were also synthesized using Cu(II), Ni(II), Co(II) and VO(IV) ions. These complexes were characterized by electronic, IR spectrophotometry, mass spectrometry, magnetic susceptibility and EDX. The compounds were thereafter evaluated for their antimicrobial and cytotoxic activities. The data obtained were supportive of an octahedral geometry for the Cu(II) complex, a square-pyramidal geometry for the vanadium complex and a 4-coordinate square-planar geometry for both the cobalt and nickel complexes. The magnetic susceptibility data revealed that the complexes are magnetically dilute and mononuclear with exception of the cobalt complex. The ligands and the complexes did not exhibit significant antimicrobial and cytotoxic assays, indicative of the nontoxicity of the ligand and complexes.

Syntheses, Characterization and Biological Activity of Novel Thiazoylazo Dye and Its Coordination Compounds

The present work describes the synthesis of a novel heterocyclic azo dye by general diazonization of 2-amino-4,5-dimethylthiazole followed by the diazo- coupling of the resulting diazonium ion with 5-methyl-2-(propan-2-yl)phenol to obtain ligand L. This was characterized using Fourier-transformed infrared and electronic spectrophotometry. Ligand L was further coordinated with five metal ions, M:L, 1:2 [M = Cu(II), Mn(II), Zn(II), Ni(II) and Co(II)]. The coordination compounds obtained were characterized by electronic, IR spectrophotometry, magnetic susceptibility and percentage metal analyses. The results obtained suggested that a thiazoylazo dye was obtained as ligand L. It was proposed that two molecules of the solvent coordinated to the metal ion in addition with the ligands to give an octahedral geometry for copper(II), manganese(II) and nickel(II) complexes. On the other hand, square planar geometry was suggested for zinc(II) and cobalt(II) complexes. The anti-infla- mmatory activity of the ligand and coordination compounds was evaluated using four in vitro-based assays viz: xanthine oxidase and lipoxygenase inhibition assay, membrane stability and protein denaturation assay. The synthesized compounds generally exhibited good anti-inflammatory activity in all the assays carried out. However, the reference standards, in this instance, were more effective in the case of xanthine oxidase, lipoxygenase and protein denaturation inhibitory assays. For the membrane stability study, the coordination compounds and ligand L elicited more potent anti-inflammatory activity than the standard drug.

Synthesis, Spectroscopic Characterization and Thermogravimetric Analysis of Cr(Ⅱ), Cu(Ⅱ), Zn(Ⅱ) and Mg(Ⅱ),Captopril Coordination Compounds

In this work,we have reported the synthesis and spectroscopic characterization of captopril(Cap)coordination compounds:Cu(Cap)·2H 2O,Cr(Cap)·H 2O,Zn(Cap)·3H 2O and Mg(Cap)4.Herein,it is worthily mentioned that the FTIR spectroscopic technique was employed to recognized the nature of coordination between captopril ligand and copper,chromium,zinc and magnesium(Ⅱ)metal ions.In view of the infrared spectroscopic tool,the copper(Ⅱ)metal ion coordinated toward captopril drug ligand through sulfur atom of SH group dependent on the absent of stretching vibration band of—SH.Based on this result,the stretching motion ofνa(COO)shifts clearly indicates that Cu 2+,Cr 2+,Zn 2+and Mg 2+the carboxylic group is employed as coordinative site for all compounds as a metal-ligand coordinative bond.As a general behavior,it is verified that the coordination compound thermal stability(considering the release of captopril molecules,not the release of water molecules)is affected by the metal cation radius:minor radius is associated with higher thermal stability,probably due to a higher metal-captopril bond dissociation enthalpy.

Mobile Equilibrium Method for Determining Composition and Stability Constant of Coordination Compounds of the Form M_mR_n

A new method is proposed for determining the composition and stability constant of coordination compounds of the form M m R n ; it can be used to differentiate mono and poly nuclear coordination compounds. The equation derived is lg( A i/(A max - A i) m)=n lg c′ R+lg( m·β(c M/A max ) ( m -1) ). The method is based on Bent French limited logarithm method. The demonstration of the proposed method has yielded correct results for Sc 3+ chlorophosphonazo Ⅲ system and Fe 3+ Chromazurol S system.

Synthesis and Structural Characterization of Mono-and Di-nuclear Zinc(Ⅱ) Coordination Compounds of Triphenylphosphoniopropionate

Two novel coordination compounds of Zn(Ⅱ) with Ph_3P+(CH_2)_2CO-_2(L), namely, [ZnL_4(H_2O)_2]·(ClO_4)_2·2H_2O(compound 1) and [Zn_2Cl_4(μ-L-O,O′)_2](compound 2), have been prepared. The single crystal X-ray structure analysis of these compounds indicates that in compound 1 the Zn(Ⅱ) atom is coordinated by four monodentate carboxylato groups on the equatorial plane and two aqua ligands occupy the axial coordination positions. The pendant oxygen atoms form strong hydrogen bonds with the aqua molecules which results in the stability of this structure. In compound 2, two Zn(Ⅱ) atoms are bridged by a pair of carboxylato groups, showing a skew-bridge mode, and thus enabling a long Zn(Ⅱ)…Zn(Ⅱ) separation. As we know, it is a dinuclear coordination compound with the longest Zn…Zn separation.

Synthesis, Characterization, Antimicrobial and DNA Binding Studies of a Tetradentate N2O2 Amino Acid Schiff Base and Its Coordination Compounds

Aminoethanoic acid undergoes condensation with 1,4-benzenedicarboxaldehyde to form an O, N, N, O donor Schiff base, N,N'-di(carboxymethylene) terephthalaldehyde, Ligand L. Coordination compounds of this Schiff base using Ni (II), Cu (II), VO (IV) and Co (II) were then obtained in-situ. The Schiff base and the complexes were evaluated for their antimicrobial and DNA binding abilities. Molecular docking studies of the ligand and synthesized compounds were also carried out. Evidence for the formation of the Schiff base coordination compounds and the coordinating atoms was obtained from 1H NMR, infrared and ultraviolet spectral data, EDX, EDTA complexometric titration and magnetic susceptibility measurement. The results obtained are consistent with octahedral geometry for Ni (II) complex, the metal ion coordinating to one molecule of Ligand L and with additional coordination with two oxygen atoms of two molecules of the solvent. A square-planar geometry was suggested for both Co (II), and Cu (II) complexes and a five-coordinate, square pyramidal geometry for the VO (IV) complex. The results further indicated that the carboxylic acid of Ligand L was not deprotonated both in the free base and also the complexes. In addition, the results showed that Compound 2 elicited the best antimicrobial activity potential. Generally, the compounds exhibited considerable good affinity to CT-DNA.

STUDY ON THE STRUCTURES OF COORDINATION COMPOUNDS OF N-(ortho-METHYL)-AND N-(ortho-METHOXY)-PHENYL IMINODIACETATO-Cu(Ⅱ)

The coordination compounds,{Cu[CH_3C_6H_4N(CH_2COO)_2]}.2H_2O and {Cu[CH_3OC_6H_4N(CH_2COO)_2]}.2H_2O,have been prepared and its crystal struc- tures determined.The final discrepancy factors are R=0.052,R_w=0.061 for (I)and R=0.052,R_w=0.039 for(Ⅱ).The geometry of the coordination poly- hedron with Cu(Ⅱ)is a distorted tetragonal pyramid for(Ⅰ)and an unsym- metrical and extended tetragonal bipyramid for(Ⅱ),respectively.The re- sults of EHMO calculations indicate that the ligand mainly provided the field with very few of its electrons being coordinated to the central atom.

Syntheses of Coordination Compounds of 2-Amino-3-Methylbutanoic Acid Their Mixed Ligand Complexes and Antibacterial Activities

Coordination compounds of 2-amino-3-methylbutanoic acid were synthesized with chromium(III) and oxovanadium(IV) ions. M:L;1:2. Adducts of these complexes using 1,10-phenantroline and ethylenediamine were further synthesized, M:L, (1:2). These compounds were characterized using electronic, infra-red spectrophotometry, magnetic susceptibility measurement and percentage metal analyses. The zones of inhibition and minimum inhibitory concentrations of the compounds against eight microbes were studied. The results obtained indicated an octahedral geometry for the Cr(III) complexes, indicative of additional coordination of two water molecules. On the other hand a square pyramid geometry was obtained for the binary oxovanadium complex and its 1,10-phenantroline adduct. However, for the oxovanadium ethylenediamine adduct a distorted octahedral geometry was proposed. The result for the antibacterial studies indicated that both mixed ligand complexes of 1,10-phenantroline exhibited good antibacterial activity, and in some cases better activity than the standard, streptomycin.

Syntheses, Characterization and Biological Activity of Coordination Compounds of 3-Hydroxy-2-methyl-4<i>H</i>-pyran-4-one and Its Mixed Ligand Complexes with 1,2-Diaminocyclohexane

Coordination compounds of 3-hydroxy-2-methyl-4H-pyran-4-one with iron(III), cobat(III) and chromium(III) were synthesized with M:L (1:2). Mixed ligand coordination compounds of 3-hydroxy-2-methyl-4H-pyran-4-one and 1,2-diaminocyclohexane using the same metal ions were also synthesized M:L1:L2 (1:1:1) where L1 is 3-hydroxy-2-methyl-4H-pyran-4-one and L2 is 1,2-diaminocyclohexane. The coordination compounds obtained were characterized using electronic and infrared spectral analyses, magnetic susceptibility and percentage metal analysis. They were also evaluated for their cytotoxic and antioxidant activities. The result obtained suggested that octahedral geometry was obtained for all the compounds, as a result of additional two molecules of the solvent coordinated to the metal ions. Both the primary and secondary ligands coordinated in a bidentate fashion. The synthesized compounds exhibited moderate cytotoxicity, although none was as active as the standard. The cobalt(III) mixed ligand complex elicited the highest activity. The synthesized compounds all exhibited good to moderate antioxidant activity.

STUDY ON THE COORDINATION COMPOUNDS OF RARE EARTHS WITH DIPEPTIDE-COORDINATION OF RARE EARTHS WITH DL-ALANYL-ALANINE

In this paper protonation constants of the title lisand and stability constants of its coordination compounds with rare earths have been determined by potentiometric titration at 25±0.1℃ and ionic strength of 0.10mol.dm^(-3)NaClO_4. The coordination of rare earths with DL-alanyl-alanine has been discussed. The stability of the coordination compound shows 'tetrad effect'. The position for yttrium shifts from its usual Bo-Er region to the vicinity of Tb.

THE SYNTHESIS AND CHARACTERISTICS OF THE COORDINATION COMPOUNDS OF 2-MERCAPTOPYRIDINE-1-OXIDE WITH THE FIPST TRANSITION SERIES METALS

The stability of the coordination compounds of the first transition series metal ions(Mn(Ⅱ),Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ)and Zn(Ⅱ))with 2-mercaptopyridine-1- oxide is reported.A coordination compound CoL_2 is synthesized and characterized for the first time.

THE SYNTHESIS AND CHARACTERIZATION OF THE COORDINATION COMPOUNDS OF Pt(Ⅱ)AND Ir(Ⅲ)WITH 2-MERCAPTOPYRIDINE-1-OXIDE AND ITS METHYL DERIVATIVES

Six coordination compounds of Pt(Ⅱ)L_2 and Ir(Ⅲ)L_3 type(where L is PT^-, 3Me-PT^-or 4Me-PT^-)are reported here.Four coordination compounds of the latter two ligands have never been reported before,while PT^-'s were synthesized with H_2PtCl_6 and(NH_4)_3IrCl_6 respectively,which were different from the methods of Davidson et al.~1 and Sterinbrech^2.They were characterized by elemental analysis, UV,IR,~1HNMR and molar conductance.Their structural formulas have been determined,and the mechanism of synthetic reaction has been discussed.

DETERMINATION OF STABILITY CONSTANTS OF THE COORDINATION COMPOUNDS OF Au(Ⅲ)-2-MERCAPTOPYRIDINE-1-OXIDE AND METHYL DERIVATIVES——METHOD OF DUAL-WAVELENGTH CORRESPONDING SOLUTIONS

In this paper,we report the deductive formula used for the method of dual-wavelength corresponding solutions under condition of having ligand interference and the stability constants of three new coordination compounds [AuL_2]^+determined with this method.The stability of the three compounds,the necessity of controlling pH in experimental systems and the advantage of this method are discussed in detail.

STUDIES ON SOLID STATE REACTIONS OF COORDINATION COMPOUNDS(LXⅡ)Solid state synthesis and crystal structure of the complex ICu_(0.84)Au_(0.16)(PPh_3)_2(SC(Ph)NHPh)CIJ·0.5CS_2

[Cu_(0.84)Au_(0.16)(PPh_3)_2(SC(Ph)NHPh)Cl]·0.5CS_2=,Mr=895.79,monoclinic,space group P2_1/a,a=17.231(3),b=14.611(2),c=18.000(3) ,β=105.56(2)°,V=4365(1) ~3, Z=4,D_c=1.37g/cm^3.,λ(MoK_α)=0.71073 ,μ=12.15cm^(-1),F(000)=1855,R=0.052, R_W=0.045 for 3930 observed reflections with Ⅰ>1.5σ(Ⅰ).The central metal atom has a dis. torted tetrahedral geometry with bond lengths Cu-S=2.384(2) (Au-S=2.389(4)), Cu-Cl=2.481(3)(Au-Cl=2.474(1))and Cu-P=2.269(2)-2.289(2)(Au-P=2.270(4)-2.279(4)) .