Radiation Polymerization of 4-(Acryloylamido)benzonitrile: Zinc and Copper Complexes

The new polymer containing cyano groups was synthesized by γ-irradiation. The oximated polymer was prepared using hydroxylamine hydrochloride in basic medium. The characterization of monomer, polymer, and oximated ones was confirmed by infrared and nuclear magnetic resonance spectroscopy. The complex formation of the amidoxime salt towards Zn^II, Cu^II, and Zn^II/Cu^II mixture in aqueous solution was studied by atomic absorption spectroscopy, energy dispersive spectroscopy, and electron spin resonance spectrometry. The significant binding capacity of these metal ions revealed its selectivity to Zinc(II) ion. The thermal stability of polymers and complexed ones was investigated using thermogravimetry analysis. The change in their morphology was observed by scanning electron microscopy (SEM).     

Zinc(II) and lead(II) coordination polymers built by 3-(4-carboxyphenylhydrazono)pentane-2,4-dione

Two coordination polymers [Zn(L)₂(4,4′-bipy)₂] _n (4,4′-bipy = 4,4′-bipyridine) (1) and [Pb(η ²-L)(µ₃-η ²-CH₃COO)(H₂O)] _n (2) have been prepared by the reaction of 3-(4-carboxyphenylhydrazono)pentane-2,4-diketone (HL) with zinc(II) or lead(II) in solution. Polymer 1 shows an infinite zigzag chain, in which Zn(II) are linked by 4,4′-bipy bridges with carboxylate of L^? monodentate to Zn(II). In 2, Pb(II) are bridged by tetradentate µ₃-η ²-CH₃COO^? to form a linear 1-D chain, and each Pb(II) is chelated by carboxylate of L^?. Their molecular structures have been characterized by elemental analysis, infrared, and single-crystal X-ray diffraction. Thermal and fluorescent properties of the two complexes have been investigated.     

Synthesis and characterization of polymeric Ni(II) complexes of 4-(4-aminobenzyl)benzenamine (abba) and 4-(4-aminophenylthio)benzenamine (aptba) with thiocyanate

Two one-dimensional complexes, [Ni(SCN)₂(abba)₂] _n (abba?=?4-(4-aminobenzyl)benzenamine) (1) and [Ni(SCN)₂(aptba)₂] _n (aptba?=?4-(4-aminophenylthio)benzenamine) (2), were synthesized and characterized by EA, IR, X-ray crystallography and thermal analysis. The single crystal X-ray structural analyses of 1 and 2 show the complexes to be 1D chain polymers as a result of dibenzenamine (dba) bridging. Each Ni is six-coordinate and adopts a slightly distorted octahedral geometry with four N atoms from four dba ligands and two N atoms from two NCS-groups. Adjacent Ni atoms and two dba ligands form a 24-membered macrocycle. Thermogravimetric analysis and differential thermogravimetric analysis of 2 show that the thermal decomposition of 2 includes four transitions.     

Vinyl Polymerization Initiated by Metal Chelates. III. Polymerization of Methyl Methacrylate Initiated by Vanadium(IV) Acetylacetonate Chelates

The polymerization of methyl methacrylate initiated by the vanadium acetylacetonate complex was investigated under a nitrogen atmosphere at 50°C. The effect of concentration of monomer, complex, acid, dioxane, inhibitor, and the effect of temperature on the rate of polymerization were studied. The rate of polymerization was found to increase upon increasing the concentrations of the monomer, the initiator, and the acid. The overall activation energy has been computed from the Arrhenius plot and a suitable kinetic scheme has been proposed.     

Synthesis and characterization of polyamides derived from (4-(4-(2, 6-diphenylpyridin-4yl)phenoxy)phenyl)-3, 5-diaminobezamide

New types of polyamides containing pendent triaryl pyridine groups were successfully synthesized by direct polycondensation of a symmetry diamine,（4-（4-（2,6-diphenylpyridin-4yl）phenoxy）phenyl）-3,5-diaminobezamide（DPDAB）, and various aromatic and aliphatic dicarboxylic diacids in NMP using triphenyl phosphate（TPP） and pyridine as catalyst. The diamine and all the prepared polyamides were fully characterized by using FT-IR,¹H-NMR,UV-Vis spectroscopy, fluorimetry and elemental analysis.The inherent viscosity of polyamides ranged from 0.45 dL/g to 0.68 dL/g.All the polymers exhibited solubility in common polar aprotic solvents such as NMP,DMAc,DMF,DMSO,pyridine,HMPA,and even in less polar solvents such as THF and m-cresol at room temperature.Thermal properties of polyamides were evaluated by means of DSC,DMTA and TGA.These polymers showed glass transition temperatures（T_g） in the range of 138-210℃. Their initial decomposition temperature（T_i） varied from 265℃to 310℃under N₂.The dilute solution（0.2 g/dL） of polyamides in DMF exhibited fluorescence emission withλ_max in the range of 470-550 nm.     

Ultrafast intramolecular charge transfer with strongly twisted aminobenzonitriles: 4-(di-tert-butylamino)benzonitrile and 3-(di-tert-butylamino)benzonitrile

The newly synthesized aminobenzonitriles with two bulky amino substituents 4-(di-tert-butylamino)benzonitrile (DTABN) and 3-(di-tert-butylamino)benzonitrile (mDTABN) have strongly twisted amino groups in the ground state. From X-ray crystal analysis it is found that the amino twist angle theta of mDTABN equals 86.5 degrees , whereas a twist angle of around 75 degrees is deduced for DTABN from the extinction coefficient of its lowest-energy absorption band in n-hexane. Because of the electronic decoupling between the amino and benzonitrile groups caused by these large twist angles, the absorption of DTABN and mDTABN is relatively weak below 40000 cm-1, with extinction coefficients around 25 times smaller than those of the planar 4-(dimethylamino)benzonitrile (DMABN). DTABN as well as mDTABN undergo efficient intramolecular charge transfer (ICT) in the singlet excited state, in nonpolar (n-hexane) as well as in polar (acetonitrile) solvents. Their fluorescence spectra consist of an ICT emission band, without evidence for locally excited (LE) fluorescence. The occurrence of efficient ICT with mDTABN is different from the findings with all other N,N-dialkylaminobenzonitriles in the literature, for which ICT only appears with the para-derivative. From solvatochromic measurements, an ICT dipole moment of 17 D is determined for DTABN as well as for mDTABN, similar to that of DMABN. The picosecond fluorescence decays of DTABN (time resolution 3 ps) are effectively single exponential. Their decay time is equal to the ICT lifetime tau'0(ICT), which increases with solvent polarity from 0.86 ns in n-hexane to 3.48 ns in MeCN at 25 degrees C. The femtosecond excited-state absorption (ESA) spectra of DTABN in n-hexane and MeCN at 22 degrees C show a decay of the LE and a corresponding rise of the ICT absorption. The ICT reaction time is 70 fs in n-hexane and 60 fs in MeCN. DTABN and mDTABN may have a strongly twisted ICT state, similar to that of 6-cyanobenzoquinuclidine but different from that of DMABN.     

两个由2-(4′-氯-苯甲酰基)苯甲酸构筑的铜、锌配合物的合成及晶体结构

通过水热法合成了2个新的配合物Cu2(cbba)4(phen)2(1)和Zn(cbba)2(bipy)(2)(Hcbba=2-(4′-氯-苯甲酰基)苯甲酸,phen=1,10-邻菲罗啉,bipy=2,2′-联吡啶),并对其进行了元素分析、红外光谱、热重和X-射线单晶衍射测定。这2个配合物通过π-π相互作用形成了三维超分子网状结构。此外,还研究了配合物2的荧光性质。     

Delphinidin–Aluminum(III) Complexes in Aqueous and Non-Aqueous Media: Spectroscopic Characterization and Theoretical Study

Summary. The study of delphinidin complexation with trivalent aluminum in acidic aqueous buffered (pH 3.0 and 3.8) and methanolic solutions was performed utilizing electronic absorption spectroscopy and quantum chemical calculations. In its structure delphinidin possesses several chelating sites in competition towards aluminum(III). Molar ratio plots denoted the formation of only one aluminum(III):delphinidin complex of stoichiometry of 1:1 in both investigated media. Semiempirical calculations, performed at the restricted HF AM1 level, enabled the determination of the structural features of free delphinidin and structural modifications caused by chelation of aluminum(III). Considering the pigment molecular structure and the results of the theoretical calculations it is possible to equally implicate C3′–C4′ and C4′–C5′ hydroxyl groups as those with the predominant chelating power.     

Copper(ll) Complexes of Diamino Diamide and Diamino Diamine in Aqueous Solution

In order to study the difference on the equilibrium, spectral properties of copper(II) complexes of diamino diamide and diamino diamine, new tetradentate ligands, 4,7‐dimethyl‐4,7‐diazadecanediamide (4,7‐N,N′‐Me₂‐L‐2,2,2) and 1,10‐diamino‐4,7‐dimethyl‐4,7‐diazadecane (4,7‐N,N′‐Me₂‐3,2,3‐tet), have been synthesized. Synthetic procedures for these new ligands are described. Their protonation constants have been determined potentiometrically in 0.10 MKC1 at 25.0°C. The formation of their copper(II) complexes have been investigated quantitatively by the potentiometric technique and by the measurement of their electronic spectra.     

4-甲氧基-3-[3-(吗啉-4-基)丙氧基]苯甲腈的合成研究

以3-羟基-4-甲氧基苯甲醛为原料,在甲酸、甲酸钠、盐酸羟胺作用下,将醛基转化为氰基,在含有碳酸钾的DMF中,所得化合物与N-(3-氯丙基)吗啉反应得目标化合物,总收率为87.5%。产物结构由1HNMR表征。本方法具有操作简单、易于纯化、收率高等特点,为工业化生产提供实验基础。     

Acetone salicyloylhydrazone of Ni(II): synthesis,molecular structures,and properties

Two new mononuclear Ni(II) complexes, [Ni(C₁₀H₁₂O₂N₂)₂(C₅H₅N)₂](NO₃)₂ (1) and [Ni(C₁₀H₁₂O₂N₂)₂(H₂O)₂](NO₃)₂ (2), have been synthesized and characterized by elemental analysis, infrared, UV-Vis spectroscopy, and single-crystal X-ray diffraction. The coordination geometry around each Ni(II) can be described as an octahedron with each Ni(II) coordinated to two imino nitrogens, two carbonyl oxygens, and two solvent molecules (pyridine for 1 and water for 2). In the synthesis, the original ligand changes from o-carboxybenzaldehyde salicyloylhydrazone (C₁₅H₁₂O₄N₂) into acetone salicyloylhydrazone (C₁₀H₁₂O₂N₂). The thermal stability of the complexes at three different heating rates (β = 5, 10, and 15°C min^?1) show that all the complexes exhibit three thermal decomposition stages and their thermal stability is 1 > 2. Complexes 1 and 2 both display DNA binding ability, ascertained by UV-Vis titration.     

Synthesis and characterization of novel fluorinated polyimides derived from 1,1′-bis(4-aminophenyl)-1-(3-trifluoromethylphenyl)-2,2,2-trifluoroethane and aromatic dianhydrides

A novel fluorinated aromatic diamine 1,1′-bis(4-aminophenyl)-1-(3-trifluoromethylphenyl)-2,2,2-trifluoroethane (6FDAM) was synthesized in a simple procedure, which was then employed to prepare a series of fluorinated polyimides with commercial aromatic dianhydrides, such as pyromellitic dianhydride (PMDA), 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane (6FDA), 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and 4,4′-oxydiphthalic anhydride (ODPA). The polyimides exhibited good solubility in strong dipolar solvents such as NMP, DMAc, DMF and m-cresol as well as some of low boiling point organic solvents of THF and CHCl₃, etc. Experimental results indicated the polyimides possessed low moisture adsorptions of 0.42-0.95%, low dielectric constant of 2.71-2.95 at 1 MHz, high dielectric strength of 92.0-122.6 kV/mm and good optical transparency with cutoff wavelengths of UV-vis at 330-375 nm. The polyimides also exhibited good mechanical properties as well as excellent thermal and thermo-oxidative stability. The fluorinated polyimides possessed better solubility, lower dielectric constant and water adsorption as well as higher optical transparency than the representative non-fluorinated polyimide derived from PMDA and 4,4′-oxydianiline (ODA).     

A Study of The Cadmium(II) Trimethylenediamine Complexes By Differential Pulse Polarography

Abstract

The overall formation constants of the Cd (Trimethylene-diamine) system were determined by differential pulse polarography at 25°C and at μ = 1 (NaNO₃). The percentage distribution of cadmium present in various forms as a function of ligand concentration was calculated.     

Two Zinc(II) and Nickel(II)‐based Complexes: Anti Breast Cancer Activity

Two zinc(II) and nickel(II) based coordination polymers, {[Zn(bibp)(MoO₄)](H₂O)₂}_n ( 1 ) [bibp = 4,4′‐bis(imidazol‐1‐yl)‐biphenyl] and [Ni₂(CN)₄(phen)₂]_n ( 2 ) (phen = 1,10‐phenanthroline), were synthesized and structurally characterized under solvothermal conditions. Compound 1 can be viewed as the connection of the 1D W‐type chain [Zn(trans‐bibp)] with the MoO₄^2– anion to form a uninodal 4‐connected net, whereas 2 features one‐dimensional Ni^II cyanide chains decorated either with linear Ni(CN)₄ side chains or with 1,10‐phenanthroline ligands bound directly to the Ni^II sites of the parent chain. In addition, in vitro anticancer activities of compounds 1 and 2 on four human breast cancer cells (MDA‐MB‐231, MDA‐MB‐468, SK‐BR‐3, and MCF7) was further determined.     

A Photoisomerizable Zinc (II) Complex Inhibits Microtubule Polymerization for Photoactive Therapy

The photoisomerization-induced cytotoxicity in photopharmacology provides a unique pathway for phototherapy because it is independent of endogenous oxygen. In this study, we developed a biosafe photoisomerizable zinc(II) complex ( Zn1 ), which releases its trans ligand ( trans -L1 ) after being irradiated with blue light. This causes the complex to undergo photoisomerization and produce the toxic cis product ( cis -L1 ) and generate singlet oxygen (¹O₂). The resulting series of events caused impressive phototoxicity in hypoxic A431 skin cancer cells, as well as in a tumor model in vivo. Interestingly, Zn1 was able to inhibit tumor microtubule polymerization, while still showing good biocompatibility and biosafety in vivo. This photoisomerizable zinc(II) complex provides a novel strategy for addressing the oxygen-dependent limitation of traditional photodynamic therapy.     

4'-(3-甲氧基-4-羟基苯基)-2,2':6', 2"-三联吡啶及其铜、锌配合物的合成、结构和性质

通过一锅反应制备了4′-(3-甲氧基-4-羟基苯基)-2,2′∶6′,2″-三联吡啶(L),通过重结晶的方法得到了其醋酸盐单晶体(HL)(CH3COO)(1),并以L为配体组装了过渡金属配合物[Cu(NO3)(CH3OH)L](NO3)(2)和[Zn(NO3)2L](C2H5OH)(3),通过元素分析、IR光谱和单晶X-射线衍射等表征了3个化合物的结构。结果表明,化合物1中,三联吡啶环呈反-反构型,而在2和3中,三联吡啶环呈现出顺-顺构型,然后采取三齿螯合模式连接金属离子形成单核单元。3个化合物中,三联吡啶分子之间以及它们与溶剂分子之间形成的氢键、π-π堆积和范德华力等相互作用将化合物1~3的单核单元连接形成三维网状结构。     

Synthesis and Properties of Complexes of Lead(II), Cadmium(II), and Zinc(II) with N-Phosphonomethylglycine

Summary.  Sparingly water soluble complexes of lead(II), cadmium(II), and zinc(II) with N-phosphonomethylglycine (glyphosate, NPMG) of the general formulae C₃H₆O₅NPPb, C₃H₆O₅NPCdċ2H₂O, and C₃H₆O₅NPZn were synthesized. The complexes were also precipited from a dilute Roundup solution, and their solubility in water was determined. Thermal, diffractometric, and IR spectrophotometric analyses were carried out. It was found that the metal is bonded to glyphosate through the oxygen atoms of the carboxylic and phosphonate groups; metal-nitrogen binding is absent in the above compounds. Studying the complexing behaviour in solution by UV spectrophotometry pointed out that a complex of the composition Pb(II) : NPMG=1:1 with an absorption band at 232 nm is formed. Its stability constant as determined by Job’s method is logK=5.9±0.1. Using potentiometric techniques, the dissociation constant of N-phosphonomethylglycine and the stability constants of its complexes with cadmium (II) and zinc (II) were determined. Received June 30, 1999/Accepted July 21, 1999.     

Copper(II) Complexes with Chiral Diaminodiamido Ligands: Solution and Structural Studies

Abstract

Three diaminodiamido ligands (S,S)-N,N′-bis(prolyl)ethanediamine (ProNN-2), (S,S)-N,N′-bis(N-methylvalyl)ethanediamine (Me₂ValNN-2), and (S,S)-N,N′-bis(N-methylphenylalanyl)-ethanediamine (Me₂PheNN-2) were synthesised and their complex formation equilibria with copper(II) investigated in aqueous solution by potentiometry and, for ProNN-2, by electronic spectrophotometry. ProNN-2 forms the species [CuLH]³⁺, [Cu₂L₂]⁴⁺, [Cu₂L₂H_?2]²⁺ and [CuLH_?2], Me₂PheNN-2 forms the complexes [CuLH]³⁺, [Cu₂L₂H_?2]²⁺ and [CuLH_?2], whereas Me₂ValNN-2 forms the monomer [CuLH_?1]⁺ but not the dimer. The dimeric cation [Cu₂L₂H_?2]²⁺, of Me₂PheNN-2 has severe steric requirements, as demonstrated by the X-ray crystal structure of the complex [Cu₂L₂H_?2]Cl₂· 12H₂O, of the corresponding non-methylated ligand. Since copper(II) complexes of the ligands examined are used as additives to the mobile phase to perform chiral resolution of D,L-amino acids in RP-HPLC, the present results provide valuable clues to an understanding of the mechanism of the enantiomeric separation.     

活性炭自溶液吸附锌(II)离子及其配合物

近年来，有人提出通过表面处理提高活性炭表面电荷，加强对无机离子吸附力等观点，但活性炭对无机离子的吸附活性点，表面含氧基团及配体对吸附的影响等重要问题仍众说纷经[1－4]为此，本文提出用氧化一负离子化法处理活性炭，以表面酸度表征表面含氧基团的量，探讨活性炭对Zn（Ⅱ）及其配合物的吸附特性．1试验（1）试验材料活性发由北京光华木材厂出品，分析纯．过20－30目，BET法测得比表面为1316m2·g-1．在2．5×10－2mlo·dm－3的NaNO3中，测得等电点pHIEP为7．75[5]，元素含量（质量分数）为C（83．9％），N（0．07％），H（1…