Kinetics on Thermal Decomposition of Iron(III) Complexes of 1,2-Bis(Imino-4’-Antipyrinyl)Ethane with Varying Counter Anions

A comparative thermal decomposition kinetic investigation on Fe(III) complexes of a antipyrine Schiff base ligand, 1,2-Bis(imino-4’-antipyrinyl)ethane (GA)), with varying counter anions viz. CIO4-, NO3-, SCN-, Cl-, and Br-, has been done by thermogravimetric analysis by using Coats-Redfern equation. The kinetic parameters like activation energy (E), pre-exponential factor (A) and entropy of activation (ΔS) were quantified. On comparing the various kinetic parameters, lower activation energy was observed in second stage as compared to first thermal decomposition stage. The same trend has been observed for pre-exponential factor (A) and entropy of activation (ΔS). The present results show that the starting materials having higher activation energy (E), are more stable than the intermediate products, however;the intermediate products possess well-ordered chemical structure due to their highly negative entropy of activation (ΔS) values. The present investigation proves that the counter anions play an important role on the thermal decomposition kinetics of the complexes.

Syntheses, Crystal Structures and IR Spectra of Two Mixed Metal Complexes:〔Cr_nFe_(3-n)(μ_3-O)-(μ-O_2CC_2H_5)_6 Py_3〕Cl(n=1,2)

Two mixed metal complexes [Cr2Fe(μ3-O) (μ-O2CC2H5)6Py3]Cl (A)and [CrFe2 (μ3-O) (μ-O2CC2H5 )6Py3] Cl (B) have been prepared in non-aqueous sol-vents. Crystal (A) is monoclinic, space group C2/c, with a= 13. 782(3), b= 18. 381(4), c= 16. 643(2) A, β= 92. 84(5)°, V=4211. 1 (4) A3, Z=4, Mr= 887. 03, Dc= 1. 40 g/cm3, μ= 5. 0 cm-1, F(000) = 1836 and R(Rw) = 0. 057(0. 062) for 2134 unique reflections with I> 3δ(I). Crystal (B) is also monoclinic, space group C2/c ,with a= 13. 793(4), b= 18. 401 (6), c= 16. 657(5) A’, β= 93. 18(3)°, V=4221. 3(5) A3, Z= 4, Mr=890. 88, Dc= 1. 40 g/cm3, μ= 10. 5 cm-1, F(000) = 1844 and R(Rw) = 0. 067 (0. 069) for 2131 unique reflections with I>3δ(I). Both (A) and (B)have been characterized by IR spectra. Besides, the relations between the structuresand IR are discussed.

STUDY ON BINUCLEAR COPPER(I)COMPLEXES III.SYNTHESIS,CHARACTERIZATION AND ELECTROCHEMISTRY OF DICHLORO-TRIS(4-VINYLPYRIDINE)-DICOPPER(I)COMPLEX

Recent years,many novel complexes have been prepared by using hetero-bidentate ligands.However,complexes with such ligands as 4-vinylpyridine which has two different coordinating sites have not been reported,and only a few complexes of Cu(I)have been published^(1-3).The title complex Cu_2(C_5H_4N·CH=CH_2)_3Cl was prepared and characterized by elemental analyses,ICP,IR,and electronic spectra.Its conductivity,oxidation potential and reduction potential were measured.

Synthesis, characterization, and stability of iron (III) complex ions possessing phenanthroline-based ligands

It has previously been demonstrated that phenanthroline-based ligands used to make gold metallotherapuetics have the ability to exhibit cytotoxicity when not coordinated to the metal center. In an effort to help assess the mechanism by which these ligands may cause tumor cell death, iron binding and removal experiments have been considered. The close linkage between cell proliferation and intracellular iron concentrations suggest that iron deprivation strategies may be a mechanism involved in inhibiting tumor cell growth. With the creation of iron (III) phen complexes, the iron binding abilities of three polypyridal ligands [1,10-phenanthroline (phen), 2,9-dimethyl-1, 10-phenanthroline (methylphen), and 2,9-di-sec-butyl-1, 10-phenanthroline (sec-butylphen)] can be tested via a competition reaction with a known iron chelator. Therefore, iron (III) complexes possessing all three ligands were synthesized. Initial mass spectrometric and infrared absorption data indicate that iron (III) tetrachloride complex ions with protonated phen ligands (RphenH+) were formed: [phenH][FeCl4], [methylphenH][FeCl4], [sec-butylphenH][FeCl4]. UV-vis spectroscopy was used to monitor the stability of the complex ions, and it was found that the sec-butylpheniron complex was more stable than the phen and methylphen analogues. This was based on the observation that free ligand was observed immediately upon the addition of EDTA to the [phenH][FeCl4] and [methylphenH] [FeCl4] complex ions.

Density Functional Theory Study on the First Hyperpolarizabilities of Mono-and Bimetal Ir(Ⅰ)/Rh(Ⅰ)2,2'-Bidipyrrins Complexes

Metal complexes with excellent nonlinear optical（NLO） properties have attracted considerable attention. The geometry structure, electronic spectra and NLO properties of 2,2？-bidipyrrins（L） and mono-and bimetal Ir（I）/Rh（I）–L complexes have been investigated by density functional theory method. Our calculations revealed that L with planar configuration shows the largest first hyperpolarizability value, which is 2.2 to 5.5 times larger than that of others. It is attributed to the single direction of intramolecular charge transfer. When metal ions were embedded in ligands, the first hyperpolarizability values of mono-and bimetal Ir/Rh（I）–L complexes were smaller than that of L, and that of bimetal Ir/Rh（I）–L complexes were smaller than the corresponding monometallic Ir/Rh（I）–L. This is caused by the intramolecular charge transfer from multiple directions as well as the amount of charge transfer. On the other hand, on increasing the number of metal ions, the charge transfer in the opposite direction cancels each other more obviously. Our work would provide some theoretical reference for the second-order NLO responses of mono-and bimetal complexes.

FERROMAGNETICALLY COUPLED Gd(III)Cu(II)Gd(III)TRINUCLEAR COMPLEXES

Three new heterotrinuclear complexes have been synthesized and characterized, namely {[Gd(L)(2)](2)[Cu(pbaOH)]}(ClO4)(4), where pbaOH denotes 2-hydroxy-1,3-propylenebis(oxamato), L stands for 1,10-phenanthroline (phen), 5-nitro-1,10-phenanthroline (NO2-phen) or 2,2'-bipyridyl (bpy). The temperature dependence of the magnetic susceptibility of ([Gd(phen)(2)(ClO4)](2)[Cu(pbaOH)])(ClO4)(2) has been studied in the 4-300K range, giving the exchange integral J = 6.69 cm(-1). This indicates a weak ferromagnetic interaction between the copper(II) and gadolinium(III) ions.

SVNTHESES AND CHARACTERIZATION OF TWO HIGH VALENCE VANADIUM COMPLEXES (?) SCHIFF-BASE LIGAND WITH RICH PHENOLATE OXVGEN AND THEIR CONVERSION

Two vanadium complexes of schiff base vith rich phenolate oxygen,o-(?)-salicylideneamino- methylphenol,had been synthesized and characterized.One is a V(Ⅳ)complex with an interaction via vanadyl oxygen and the other is a novel dinuclear V(V,V)complex with an oxo bridge.The conversion between the two complexes had been discussed.

PRELIMINARY STUDIES ON THE SYNTHESIS AND CHARACTERIZATION OF OXY-AND THIO-DIACETIC ACID HYDRAZITION AND THEIR FIRST-ROW TRANSITION METAL COMPLEXES

It has been made certain that thio-and oxy-diacetic acid hydrazides are potential anticancer compounds.However,their ability to form complexes with transition metals and the properties of the complexes thus formed have not been studied.Employing a new potential anticancer ligand 1,2-bis(thioacetic acid hydrazide)ethane prepared in our lab,along with ligands oxydiacetic hydrazide and 1,2-bis(oxyacetic acid hydrazide) ethane,a series of 11 new first-row transition metal(M=Zn^(2+),Cu^(2+),Co^(2+), Ni^(2+))complexes with each of the above three ligands have been synthesized and characterized by means of elemental analyses,IR,TG and X-ray powder diffraction.

Syntheses,Crystal Structures and Antibacterial Activities of Complexes [(C_9H_(18)NS_2)_3M(Ⅲ)](M = Sb and Bi)

Two novel complexes,[（C9H18NS2）3Sb（III）]（1） and [（C9H18NS2）3Bi（III）]（2）,were synthesized and characterized by elemental analysis,IR,TG and X-ray single-crystal diffraction.Both 1 and 2 crystallize in the monoclinic system,P21/c space group.The data for 1：a = 1.6964（3）,b = 1.02149（17）,c = 2.5650（3） nm,β = 121.824（8）°,Z = 4,V = 3.7766（10） nm^3,Dc = 1.293 g·cm^-3,F（000） = 1536,μ = 1.082 mm^-1,the final R = 0.0500,wR = 0.1562 and S =1.072.The data for 2：a = 1.6802（9）,b = 1.0256（6）,c = 2.5083（10） nm,β = 121.77（3）°,Z = 4,V = 3.675（3） nm^3,Dc = 1.486 g·cm^-3,F（000） = 1664,μ = 5.159 mm^-1,the final R = 0.0481,wR = 0.1055 and S =1.076.The coordinated geometry of the central M（III） with six sulfur atoms from three ligands is a distorted pentagonal pyramid configuration.The dimer structural system is formed by the weak interactions of M…S and C-H…S between two molecules.The complexes were valued for their antibacterial activities by agar-streak method.It was found that 1 is active against the four test bacterial organisms.

Progresses in electroluminescence based on europium(Ⅲ) complexes

The research on electroluminescence based on europium（III） complexes has come to an important phase. This article reviewed the progresses in photoluminescence and electrohiminescence of Eu（III） complexes in recent years from the views of the design of Eu（III） complexes and optimization of device structures, and discussed some important factors influencing electroluminescence performance. The problems existing in the practical application such as the volatility and thermal stability of Eu（III） complexes in this area were discussed, and the possible corresponding solutions were briefly prospected.

Synthesis, Characterization and Fluorescence of Terbium(Ⅲ) Complexes with Phenylglyoxylic Acid and 2,2-Dipyridine, 1,10-Phenanthroline, Triphenyl Phosphine Oxide

Three new complexes TbL3dipy （H2O）2, TbL3phen （H2O） 2 and TbL2 （TPPO） 2NO3 were synthesized （L = phenylglyoxylate ion, dipy = 2, 2-dipyridine, phen = 1,10-phenanthmline, TPPO = Triphenyl phosphine oxide）. Elemental analysis, conductivity, IR spectra, and ^1HNMR spectra studies were performed. IR spectra indicate that the carboxylate ion of phenylglyoxylate is coordinated to the Tb（Ⅲ） ion as an unidentate ligand. In ^1HNMR, the signals of different hydrogens in phenylglyoxylate ion shift upfield. The excitation and emission spectra of the three solid complexes were recorded at morn temperature, in which the optimum excitation wavelengths are, 361.0, 359.0 and 367.0 nm for these three complexes, respectively. Four emission bands due to the ^5D4-^7Fj（j = 6, 5, 4, 3） transitions were observed for TbL3dipy（H2O）2（489.0, 545.0, 584.0, 620.0 nm） and TbL3phen（H2O）2（490.0, 544.0, 583.0, 620.0 nm）. Under the same conditions, only one emission band due to the ^5D4-^7F5 transition was observed for the complex TbL2（TPPO）2NO3. The emission intensity of TbL3dipy（H2O）2 is the strongest among the three complexes.

The Aggregates in LB Films of Schiff base Aluminium (III) Complex

The surface pressure-area (pi -A) isotherm of Schiff base aluminium (III), tris (2-hydroxy-5-nitro-N-dodecyl-benzylideneaminato) aluminium (III) (denoted as Al(TAl2)(3)), on pure water subphase was investigated. The molecular area, 0.48 nm(2), is one-third of expected value that indicated the aggregation took place. The Langmuir-Blodgett (LB) films of Al(TAl2), was transferred and characterized. The AFM image confirmed the formation of aggregates.

Investigation on the syntheses and structures of Y^(Ⅲ) complexes with ami-nopolycarboxylic acids (Ⅳ)

This paper deals with the structure of the Y^iii complex withaminopolycarboxylic acids, synthesis and struc- tural determinationof the complex (NH_4)[Y^III(edta)(H_2O)_3] ·3 H_2O (edta =ethylenediaminetetraacetic acid). The crystal and molecularstructures of the (NH_4)[Y^III(edta)(H_2O)_3] ·3 H_2O complex havebeen determined by single-crystal X-ray structure analysis. Thecrystal of the complex (NH_4)[Y^III(edta)(H_2O)_3] ·3 H_2O belongsto orthorhombic crystal system and fdd2 space group.

环金属配体Ir(Ⅲ)配合物结构、光谱和量子效率的理论研究

对一类环金属Ir(Ⅲ)[(C^N)_(2)Ir(A^A)]配合物[C^N=ptaz(1,2,4),mhtz(3),ptaz=3,4,5-三苯基-4H-1,2,4-三唑,mhtz=1,3-双甲基-5-苯基-1H-1,2,4-三唑;A^A=pzpy(1),npzpy(2,3),bicb(4),pzpy=2-(1H-吡唑-1-基)吡啶,npzpy=4-二甲基氨基-2-(1H-吡唑-1-基)吡啶,bicb=3,3′-亚甲基双(1-甲基-1H-咪唑-2-亚基)]的结构、光谱特征和磷光量子效率进行了理论研究.计算方法探究表明,基于B3LYP泛函优化的基态结构和单激发组态相互作用(CIS)方法得到的激发态结构计算的吸收和发射光谱更准确.配合物1~4的最低吸收峰和发射峰分别位于408,376,382,365 nm和503,506,468,511 nm处,其HOMOs主要由金属和C^N配体占据,而配合物1~3的LUMOs由A^A配体的π反键轨道组成,配合物4的LUMO存在于C^N配体上.因此,配合物4的最低吸收峰和发射峰具有与配合物1~3不同的金属到配体和配体内部(MLCT/ILCT)的混合跃迁性质,非共轭N^N配体的引入显著消弱了其在跃迁过程中的贡献程度.配合物1~4的量子效率取决于非辐射跃迁速率常数k_(nr),这与它们重组能的贡献[4569 cm^(-1)(3)>2583 cm^(-1)(1)>1232 cm^(-1)(2)>975 cm^(-1)(4)]相一致,表明主配体的体积和辅助配体的共轭能力都能影响配合物的磷光量子效率.

Synthesis, Characterization and Fluorescence Studies on Complexes of Terbium with Phenylglyoxylic Acid, 2,2-Dipyridine, 1,10-Phenanthroline, Triphenyl Phosphine Oxide

Three new complexes TbL3dipy （H2O）2, TbL3phen （ H2O ）2 and TbL2 （ TPPO ）2NO3 have been synthesized （L = phenylglyoxylate ion, dipy = 2, 2- dipyfidine, phen = 1,10-phenanthroline, TPPO = Triphenyl phosphine oxide ）. Elemental analysis, conductivity, IR spectra and ^1HNMR spectra studies were performed on them. IR spectra indicate that carboxylate ions in the phenylglyoxylate are coordinated to Tb （Ⅲ） ions as unidentate ligands. In ^1HNMR, the signals of hydrogens in phenylglyoxylate shift upfield. The excitation and emission spectra of the three comolexes were recorded at room temoerature, the excitation spectra show that the optimum excitation wavelengths are 361.0, 359.0 and 367.0 nm, respectively. Four emission bands due to ^5D4-^7Fj （j = 6, 5, 4, 3 ） transitions were observed for TbLadipy （ H2O ）2 （489.0, 545. 0, 584.0,620.0 nm） and TbL3phen （H2O）2 （490. , 544.0, 583.0, 620.0 nm）. And under the same conditions, only one emission band due to ^5Da-^7F5 transition was observed for TbL2 （TPPO）ENO3. The emission intensity of TbLadipy （H2O）2 is the strongest among the three complexes.

Crystal Structures and Photoluminescence Properties of Two Lanthanide Complexes Constructed by Flexible 1,2-Phenylenediacetic Ligand

Two 3D Ln-organic coordination frameworks（Ln = Pr3＋ for 1 and Er3＋ for 2） have been constructed. Single-crystal X-ray diffraction analysis reveals that the two complexes have similar structures and belong to the monoclinic C2/c space group. The trans-μ4-（η2：η1）-（η1：η1） 1,2-pda2- anions link the LnIII centers to generate a 2D network containing helical motif. The dimensionality is extended into a 3D architecture through cis-bis（μ2-η2：η1） 1,2-pda2- anions linking. The geometry of Ln3＋ ions is single-capped anti-square prism. Two complexes were characterized by IR spectra and thermogravimetric analysis. The solid fluorescence of 1 and 2 was also investigated at room temperature.

Designed Syntheses and Crystal Structures of Two Cis-cyanide Bridged Trinuclear Complexes

Two cyanide bridged trinuclear compounds [Fe（bpy）2（CN）2]·[Cu（Cyclam）]2（ClO4）4·DMF 1 and [Fe（Phen）2（CN）2]·[Cu（Cyclam）]2（ClO4）4·2CH3CN·4H2O 2 （Bpy = 2,2＇- bipyridine, Phen = 1,10-phenanthroline, Cyclam = 1,4,8,11-tetraaza-cyclotetradecane, and DMF = N,N-dimethylformamide） have been synthesized by using mononuclear [Fe（Phen）2（CN）2]·2H2O and [Fe（bpy）2（CN）2]·3H2O as precursors. These two complexes crystallize in monoclinic space groups P21/c and C2/c, respectively. For 1, a = 25.164（2）, b = 12.0405（11）, c = 20.4433（15） A, β = 91.948（3）°, V = 6190.5（9） A^3, Z = 4, Mr = 1418.90, Dc = 1.522 g/cm^3, F（000） = 2936, μ = 1.161 mm^-1, the final R = 0.0722 and wR = 0.2011 for 10779 observed reflections （I 〉 2σ（I））. For 2, a = 43.5945（0）, b = 11.8447（0）, c = 29.5637（2）A, β = 120.430（11）o, V = 13162.76（9） A^3, Z = 8, Mr = 1518.48, Dc = 1.533 g/cm^3, F（000） = 6288, μ = 1.101 mm^-1, the final R = 0.0711 and wR = 0.1783 for 11262 observed reflections （I 〉 2σ（I））.

Syntheses, Crystal Structures and Anticancer Activities of Dithiocarbamate Bismuth(Ⅲ) Complexes

Two novel complexes, [Bi（III）（S2CNBn Et）3] 1 and [Bi（III）（S2CNPPPy-2）3] 2, were synthesized and characterized by elemental analysis, IR, ^1H NMR, ^13C NMR, TG-DTG and X-ray single-crystal diffraction. The structure reveals that complex 1 belongs to the monoclinic system, space group P21/c with a = 11.457（5）, b = 17.437（8）, c = 33.439（14）, β= 98.499（8）o, Z = 4, V = 6607（5）3, Dc = 1.689 g·cm^-3, F（000） = 3328, μ= 5.742 mm^-1, the final R = 0.0906, w R = 0.1678 and S = 1.032. The structure indicates that complex 2 belongs to the triclinic system, space group P1 with a = 12.608（9）, b = 12.622（8）, c = 12.49（6）, α = 102.652（15）, β = 103.013（14）, γ = 109.698（10）o, Z = 1, V = 1762.3（19）3, Dc = 1.741 g·cm^-3, F（000） = 916, μ = 5.395 mm^-1, the final R = 0.048 2, w R = 0.1206 and S =1.046. In the two complexes, each six-coordinated Bi（III） atom adopts a pentagonal pyramidal configuration with six sulfur atoms from three ligands, and the dimmer structures are formed by weak interactions of Bi···S between two molecules. The anticancer activities of the two complexes were studied by evaluating their cytotoxicities against several human cancer cell lines using the MTT assay. Results indicated complex 2 showed moderate cytotoxic effects on the selected cancer cells.

CRYSTAL STRUCTURE OF A 2D SHEET－LIKE μ－CYANIDO－OXAMIDATO BRIDGED Fe（III）－Cu（II） HETERNUCLEAR COMPLEX

The synthesis is and crystal structure are reported for the sheet-like compourd [CU2(oxpn)Fe(CN )5(NO)]. there oxpn is the dianion of M, M'-bis(3-aminopropyl)oxamide. This compound crustallizes in the orthogonal space group Puma. with a=11 .413(4), b=22.242(5), c=7.736(2) A, and Z=4.The structure was refined to conventionat discrepancy factors R=0.047 and Pw=0.054. The Cu(II ) and Fe(III)centers are bridged by oxpn and cyanide, the formal behaves as a his-terdentate tigand bound to cooper(II)ion to form (II) dimers. whereas the latter bridges Cu(II) and Fe(III) centers in both symmetric and asymetric end- to-end bis-monodentate fashions, spreading out along be plane to form a 20 network. The Structure is made up of CuFe unit with Cu(II) and Fe(III) ions locating in a distorted square-based pyramid and a compressed octahedron, respectively.

Synthesis and Crystal Structure of Tris(N-p-methylphenyl-3-hydroxy-2-ethyl-4-pyridinonato)iron(III)

The complex [Fe(C14H14NO2)3]2H2O has been prepared by reaction of N-p-methylphenyl-3-hydroxy-2-ethyl-4-pyridinone with FeCl36H2O. A single-crystal X-ray study shows that the iron atoms lie in a trigonally distorted octahedral environment coordinated to the hydroxy and ketone oxygen atoms of three ligands in the mer configuration Mr=773.57(C42H46N3O8Fe). The crystal is hexagonal with space group P31c; a=15.943(2), c=17.612(4)? V=3877.0(12)?, Z=4, Dc=1.325g/cm3, m=0.445mm-1, F(000)=1634, R=0.0446, wR= 0.1154 for 3085 reflections with I >2s(I). The bond lengths from iron to oxygens are 1.980(1)?for the ketone oxygens and 2.071(1)?for the hydroxy oxygens. The molecule exhibits the expected propeller shape, and the angle of the trigonal twist is 48.37. The dihedral angles are 0.5(2)?between chelate ring plane and pyridine ring plane and 71.31(7)?between pyridine ring plane and benzene ring plane. The solvent H2O(O(3) and O(4)) molecules are linked with O(2) and O(1) by hydrogen bonds with bond lengths 2.900(1) and 2.999(1)? respectively.