Studies of Copper(II) Thiosemicarbazide Complexes and their Reactivities. X-Ray Structure of Two Unusual Reaction Products, [Cu(bpy)(H2O)2SO4] and [(bpy)2Cu2(C2O4)Cl2]·H2O

A number of ternary complexes of Cu²⁺ with thiosemicarbazide (TSC) including [Cu(bpy)(TSC)₂]Cl₂, [Cu(o-phen)(TSC)₂]Cl₂ and [Cu(bpy)(TSC)₂][CuCl₄] [Cu(o-phen)(TSC)₂] [CuCl₄] have been synthesised and characterized. Their reactivities in aqueous and DMF solutions were studied. It was observed that while on coordination to Cu²⁺ thiosemicarbazide is converted to thiocyanate in aqueous solution, in DMF solution the thiocyanate is further aerially oxidised to sulfate. In the presence of hydrogen peroxide, oxidation to sulfate is rapid and from the mother liquor we could isolate [(bpy)₂Cu₂(C₂O₄)Cl₂]·H₂O whose structure was determined by X-ray crystallography. X-ray crystal structure of [Cu(bpy)(H₂O)₂SO₄] is also discussed.*     

Thiosemicarbazone Complexes of Ruthenium(II) and Rhodium(I) Containing Triphenylphosphine

Several new hexa-coordinated ruthenium(II) and penta-coordinated rhodium(I) complexes of the types [RuCl(CO)(PPh ₃ ) ₂ (TSC)], [RuH(CO)(PPh ₃ ) ₂ (TSC)], and [Rh(PPh ₃ ) ₃ (TSC)] (where TSC = anion of thiosemicarbazone Schiff bases) have been prepared by the reactions of [RuHCl(CO)(PPh ₃ ) ₃ ], [RuH ₂ (CO)(PPh ₃ ) ₃ )], and [RhH(PPh ₃ ) ₄ ] with thiosemicarbazones of 2-furaldehyde (H-FTSC), thiophene-2-carboxaldehyde (H-TCTSC), p-anisaldehyde (H-ATSC), piperonaldehyde (H-PTSC), and cyclohexanone (H-CTSC). All the new complexes obtained have been characterized on the basis of elemental analysis, IR, ¹ H NMR, ³¹ P NMR, and electronic spectral data.     

A Novel Copper Oxide Nanoparticle Conjugated by Thiosemicarbazone Promote Apoptosis in Human Breast Cancer Cell Line

The current study highlights the apoptotic activity of copper oxide (CuO) nanoparticles functionalized by Glutamic acid and conjugated by thiosemicarbazone (TSC) toward human breast cancer (MCF-7) and normal (HEK293) cell lines. To this aim, the co-precipitation method was used for preparation the CuO nanoparticles. Afterward, the CuO nanoparticles functionalized by glutamic acid. After that the functionalized copper oxide nanoparticles (CuO@Glu) conjugated to thiosemicarbazone. In next step, the final nanoparticle product (CuO@Glu/TSC) was characterized by physico-chemical techniques including Fourier transform infrared (FT-IR) spectroscopy, Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Energy dispersive X-ray analysis (EDX), zeta potential analysis and dynamic light scattering (DLS). The effects of in vitro cell viability in CuO@Glu/TSC nanoparticles showed the anti-proliferative properties with a dose-dependent manner (IC₅₀?=?133.97 µg/ml). The IC₅₀ of CuO@Glu/TSC on normal cell line was 230.2 µg/ml. This IC₅₀ deference shows high cytotoxicity of CuO@Glu/TSC nanoparticles on tumor cells and low cytotoxicity on non-tumorigenic cells (HEK293) and is considered as an important aspect for this nanoparticles. Also, CuO@Glu/TSC nanoparticles had efficient effects in inhibiting the growth of breast cancer cell line (MCF-7). In addition, the CuO@Glu/TSC nanoparticle induced apoptosis symptoms which were assessed by Caspase-3 activation assay, Annexin V/ propidium iodide flow cytometry, and Hoechst 33258 staining. Further, Bax and Bcl-2 genes expression was estimated by real time PCR. The expression of Bax increased 1.69 fold, while the expression of Bcl-2 decreased 0.6 fold. The results of the current study propose that CuO@Glu/TSC nanoparticles reveal effective anti-cancer activity against breast cancer cell line.

     

Synthesis,structure and antiproliferative activity of dinuclear ruthenium arene complexes with differently coordinated thiosemicarbazones

A series of di‐nuclear ruthenium arene complexes with TSC ligands ([(η⁶‐p‐cymene)Ru(N¹,S‐TSC)]₂Cl₂, A‐type, 1 and 2 ) and their corresponding analogues ([(η⁶‐p‐cymene)Ru(N²,S‐TSC)]₂Cl₂, B‐type, 3 and 4 ), in which TSCs act as different coordination mode, have been synthesized and structurally characterized by a variety of physical methods. The molecular structures of 1 , 3 and 4 were determined using single‐crystal X‐ray diffraction analysis. The Gibbs free energy of the two examples of the two types of complexes ( 1 and 3 ) and bonding order in their single‐crystals were discussed using density functional theory (DFT) calculations. The compounds were further evaluated for their in vitro antiproliferative activities against several cancerous and HEK‐293 T noncancerous cell lines, and the results indicate that B‐type complexes show stronger cytotoxicity than A‐type complexes. Furthermore, the interactions of the compounds with DNA were investigated by electrophoretic mobility spectrometry studies.     

Influence of tacticity on Tβ, Tg,and TLL in poly(methyl methacrylate)s by the method of thermally stimulated current (TSC)

The thermally stimulated-current method (TSC) has been employed to determine the temperatures and intensities of T_β, T_g, and T > T_g for pure isotactic, pure syndiotactic, and five atactic specimens with syndiotactic triad content from 49.5 to 75%; T_g was found to increase linearly with syndiotactic triad content as T_g (°C) = 48.0 + 0.856 (% syn), with R² = 0.970 standard error 5.6°C; T_g for the syndiotactic specimen is 136.6°C measured, 133.6°C calculated. Several atactic specimens exhibit a second glass temperature 15 to 35 K above the regression line ascribed to some pure syndio content, and/or some isotactic–syndiotactic stereocomplexes. All specimens exhibited the liquid–liquid or T_LL transition (relaxation) which increases linearly with 100-% isotactic triad content. Isotactic PMMA shows a T′_LL relaxation 50 K above T_LL. The T_g and T_LL values obtained correlate extremely well with values from differential scanning calorimetry (DSC) determined in a separate study, as well as with most literature data. Intensities of T_g and T_LL by TSC are greatest for isotactic, next for syndiotactic, with a broad, low minimum for atactic materials. The intensity of a β relaxation increases slowly from isotactic to syndiotactic. The T_LL found by TSC compares well with literature values for isotactic PMMA obtained by several methods, and T_LL in the atactic region compares well with literature values for atactic material. The ratio T_LL/T_g ranges from 1.09 to 1.20 with no dependence on tacticity. T_g follows simple Arrhenius behavior with enthalpies of activation about one-half of the values normally calculated from dielectric and mechanical loss. The frequency dependences of T_LL and T′_LL follow a Vogel–WLF relationship with temperature. The origin of T_LL is discussed in terms of the Frenkel hypothesis of segment–segment interaction. Evidence for T_LL and T_LL from a variety of methods indicates that these two temperatures are not artifacts of the TSC method.     

Study of the molecular mobility of collagen

The dielectric relaxations of a biopolymer, collagen, have been studied by means of the thermally stimulated current (TSC) technique. To investigate effects of water on TSC spectra, complementary measurements by differential scanning calorimetry (DSC) have been performed. In dehydrated collagen, three spectral bands were recorded in the temperature range of -180-60°C, labelled α, β₁, and γ in the order of decreasing temperature. The TSC spectrum of hydrated collagen exhibits a supplementary band labelled β₂. By using the fractional polarization method, the γ and β₁ modes have been attributed to localized movements of nonpolar (apolar) sequences and polar sequences, respectively. The α mode has been associated with delocalized movements of the collagen macromolecules. Finally the β₂ mode has been attributed to reorientations of bound water molecules inside the collagen fibers. © 1995 John Wiley & Sons, Inc.     

热释电流法研究聚对苯二甲酸乙二醇酯的Sub-T_g存放

测量了一系列在T相似文献   

Recombination in complex systems – an analytical approach

A new analytical model is proposed to describe the kinetics of trapping and recombination of charge carriers in complex systems with an arbitrary spatial distribution of traps and recombination centres. The structural properties of a material are described by two functions Γ_m and Γ_n irrespective of the thermal history of the sample. A simple method is proposed to determine the function Γ_m from simultaneous thermoluminescence (TL) and thermally stimulated conductivity (TSC) measurements.     

Novel microwave synthesis of half‐sandwich [(η6‐C6H6)Ru] complexes and an evaluation of the biological activity and biochemical reactivity

We have used a novel microwave‐assisted method to synthesize a pair of half‐sandwich ruthenium–arene–thiosemicarbazone complexes of the type [(η⁶‐C₆H₆Ru(TSC)Cl]PF₆. The thiosemicarbazone (TSC) ligands are 2‐(anthracen‐9‐ylmethylene)hydrazinecarbothioamide and 2‐(anthracen‐9‐ylmethylene)‐N‐ethylhydrazinecarbothioamide derived from 9‐anthraldehyde. The complexes are moderately strong binders of DNA, with binding constants of 10⁴ m ^?1. They are also strong binders of human serum albumin, having binding constants of the order of 10⁵ m ^?1. The complexes show some in vitro anticancer activity against human colon cancer cells, Caco‐2 and HCT‐116, with positive therapeutic indices. They did not show any activity as antibacterial agents against the organisms that were studied. Copyright © 2013 John Wiley & Sons, Ltd.     

Dependence of dielectric,ferroelectric, and piezoelectric properties on crystalline properties of p(VDF‐co‐TrFE) copolymers

Thermal processing at various temperatures has been used to fabricate poly(vinylidene fluoride‐co‐trifluoroethylene) [P(VDF‐co‐TrFE)] films with varied crystalline properties in an attempt to improve their piezoelectric properties. Although the dielectric constant of the films annealed at higher temperature is smaller than that of cooled and quenched ones, it has been shown that the annealed films possess larger crystallinity and stacked lamellar crystal grain size. The ferroelectric domains deriving from crystal region in all the samples are effectively improved by hot polarization. As a result, the remnant polarizations (P_r) and coercive electric field (E_c) of the corresponding films are improved at a low frequency due to the response of dipoles in crystal phase, and the largest piezoelectric constant in the longitudinal thickness mode (d₃₃=?25 pC/N) is obtained in an annealed copolymer film. The results illustrate improving the crystal structure of P(VDF‐co‐TrFE) is an effective way to realize high electromechanical properties, which provides broadly applied scenery for this kind of copolymer in piezoelectric components. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012     

A.C. dielectric and TSC studies of constrained amorphous motions in flexible polymers including poly(oxymethylene) and miscible blends

Poly(OxyMethylene) (POM) and its miscible blends were studied by multifrequency A.C. dielectric and thermally stimulated currents (TSC). The blends contained small amounts of either poly(vinyl phenol), which is a high glass transition (T_g) diluent, or a styrene-co-hydroxy styrene oligomeric low T_g diluent. The variation of the 10°C “β” transition with blend composition proves that it is the glass transition, and that the −70°C “γ” transition is a local motion. Dielectrically the β transition is very weak in pure POM even in fast-quenched samples. The TSC thermal sampling method also detected two cooperative transitions, γ and β, in POM and its blends, and was used to directly resolve the γ transition into low and high activation energy components. If one considers the contribution of exclusion of the diluents from the crystal lamellae, it is shown that the blends behave like typical amorphous blends as a function of concentration. The effect of crystals on amorphous motions is examined in light of comparison with van Krevelen's³⁷ predictions of an “amorphous” T_g, and the transitions in POM are contrasted with those for other semicrystalline polymers. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2121–2132, 1997     

Cooperative motions in PVC studied by thermally stimulated currents: Comparison with A.C. dielectric derivative analysis

The thermally stimulated current–thermal sampling (TSC–TS) technique was used to study the broadened glass transition in conventional “atactic” poly(vinyl chloride), PVC. The activated parameters obtained from the TSC–TS data, mainly the apparent activation energy (E_a), characterize the breadth of glass transitions in a very sensitive way. These results are compared with those values of E_a obtained from the literature, using a recently proposed method of analyzing a.c. dielectric constants and their derivatives, over the temperature range of −100–130°C. Both techniques detect weak cooperative glass transition-like relaxations well below the main glass transition of ca. 80°C. As is the case with “atactic” PMMA, the data suggest that compositional heterogeneity related to a small fraction of predominantly isotactic sequences contribute to the broad glass transition extending ca. 60°C below the main glass transition in atactic PVC. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 913–918, 1998     

EPR of vanadyl ion in a natural mineral, apophyllite

Single crystal EPR spectra of a natural mineral, apophyllite, containing VO(II) ion as an impurity have been investigated. The EPR spectra of the mineral, as obtained, was complex in nature, but was simplified by annealing the crystals at 490 K. The EPR parameters of the VO(II) species in the annealed crystal,g _∥ = 1.924 (2);g _⊥ = 1.983 (2);A _∥ = 18.35 (5); andA _⊥ = 7.24 (5)mT, are very close to a typical VO(II) impurity. Theoretically calculated line positions, using second-order hyperfine terms in the spin Hamiltonian with an axially symmetricg andA tensor values, agreed very well with the experimental ones. The EPR analysis of the annealed crystal has further revealed that the most preferred location of the VO(II) impurity is a substitutional Ca(II) site. The calculated bonding parameters and admixture coefficients indicate a fair amount of covalent bonding in the complex.     

Thermally stimulated current studies of thermotropic polyesters with polymethylene spacers (I): The glass transition and relaxation behavior of anisotropic and isotropic glasses

Thermally stimulated current (TSC) and relaxation map analysis (RMA) were used to study the glass transitions and relaxation phenomena of the anisotropic and isotropic glasses for the semiflexible polyesters with various polymethylene spacers (n = 7 ˜ 10). TSC analysis indicated that the glass transition temperatures (T_g) of polymers at around 40 ˜ 50°C exhibited an apparent even-odd behavior not only for the anisotropic glasses but also for the isotropic glasses. The T_g of the isotropic glass for the polymer with even n value was observed to be higher than those for the two neighboring polymers with odd n values. The anisotropic glass for the polymer with even n value had a lower T_g than those for the two neighboring polymers with odd n values. The lower value was attributed to the configuration and orientation effects on the behavior of polarization. RMA revealed that the relaxation modes of the investigated polymers were also influenced by the configuration and orientation effects. The dipolar relaxation of the anisotropic glass for the polymer with odd n value occurred at a higher temperature and had a lower entropy (enthalpy) of activation than that of the isotropic glass for the same polymer due to the orientation effect. However, an inverse relation was found to occur for the polymer with even n value, which came from the trans configuration of the even polymethylene spacers. Finally, the thermokinetic properties evaluated by RMA (e.g., the final state after depolarization) correlated quite well with the results obtained by TSC. © 1995 John Wiley & Sons, Inc.     

Thermally stimulated current and DSC studies of the broadened glass transition in liquid crystalline polymers

The high sensitivity of the thermally stimulated current, thermal sampling (TS) method is emphasized in a study of the breadth of the glass transition in several liquid-crystalline polymers (LCPs). Differential scanning calorimetry (DSC) was performed on all samples to further quantify the glass transition regions. For “random” copolyester LCPs with widely varying degrees of crystallinity, including highly amorphous samples, very broad glass tran-sition regions were observed. One semicrystalline alternating copolyester and a series of semicrystalline azomethine LCPs were studied as examples of structurally regular polymers. These exhibited relatively sharp glass transitions more comparable to ordinary isotropic amorphous or semicrystalline polymers. The broad glass transitions in the random copolyesters are attributed to structural heterogeneity of the chains. In one example of a moderate-crystallinity random copolyester LCP (Vectra), glass transitions ranging up to ca. 150°C in breadth were determined by the thermal sampling (TS) method and DSC. In other lower crystallinity copolyester LCPs, the main glass transition temperature as determined by DSC was comparable to that determined by TSC although cooperative relaxations of a minor fraction of the overall relaxing species were detected well below the main T_g, by the TS method and not by DSC. Rapid quenches from the isotropic melt to an isotropic glass were possible with one LCP. The anisotropic and isotropic glassy states for this LCP were found to have the same breadth of the glass transition as was determined by the TS method, although TSC and DSC show that T_g is shifted downward by ca. 15°C in the anisotropic glass as compared to the isotropic glass. © 1993 John Wiley & Sons, Inc.     

超声电化学制备PbSe纳米枝晶

近年来，纳米晶态半导体粒子因其具有大的表面体积比、高的活性、特殊的电学性质和独特的光学性质引起了科学界的广泛关注犤１，２犦。基于半导体纳米粒子的量子尺寸效应和表面效应，半导体纳米粒子在发光材料犤３犦、非线性光学材料犤４犦、光敏传感器材料犤５犦、光催化材料犤６犦等方面具有广阔的应用前景。如何实现对半导体纳米粒子的尺寸大小、粒度分布以及形状和表面修饰的控制，寻找更简便的合成方法以及改善制备环境等是半导体纳米粒子研究的关键。超声电化学是结合了电化学和超声辐照而建立起来的一种新方法，它显示了两者的优点犤…     

Thermally stimulated current (TSC) study of the Tg and Tll transitions in anionic polystyrenes

The thermally stimulated current (TSC) technique has been used to investigate three anionic polystyrenes of M?_n 17,000, 71,700, and 1.55 × 10⁶, i.e., M < M_c, M > M_c, and M ? M_c, where M_c is the entanglement molecular weight. A current maximum near T_g designated T_Mg, has relaxation times which follow an Arrhenius equation. A second current maximum at T > T_g appears to be the T_ll process and is designated T_Mll. Relaxation times for it follow a Vogel equation. T_Mg and T_Mll vary with molecular weight, increasing below M_c and leveling off above M_c at a temperature of about 170°C. Values of T_Mg and T_Mll are compared with values of T_g and T_ll obtained from torsional braid analysis, which involves melt flow; and with differential-scanning-calorimetric values on fused films, where there is no transport of polymer. It is concluded from such cross-comparisons that TSC, at least for polystyrene, is a quasistatic test which may involve microscopic viscosity. Macroscopic viscosity does not play a role. The ratio T_Mll/T_Mg is in the range 1.10–1.16, similar to T_ll/T_g values by other methods. A few comments about T_ll in atactic poly(methyl methacrylate) by the TSC method are given.     

Characteristics of Ag/Bi<Subscript>3.25</Subscript>La<Subscript>0.75</Subscript>Ti<Subscript>3</Subscript>O<Subscript>12</Subscript>/p-Si heterostructure prepared by sol-gel processing

The metal-ferroelectric-semiconductor (MFS) heterostructure has been fabricated using Bi_3.25La_0.75Ti₃O₁₂ (BLT) as a ferroelectric layer by sol-gel processing. The effect of annealing temperature on phase formation and electrical characteristics of Ag/BLT/p-Si heterostructure were investigated. The BLT thin films annealed at from 500°C to 650°C are polycrystalline, with no pyrochlore or other second phases. The C-V curves of Ag/BLT/p-Si heterostructure annealed at 600°C show a clockwise C-V ferroelectric hysteresis loops and obtain good electrical properties with low current density of below 2×10⁻⁸ A/cm² within ±4 V, a memory window of over 0.7 V for a thickness of 400 nm BLT films. The memory window enlarges and the current density reduces with the increase of annealing temperature, but a annealing temperature over 600°C is disadvantageous for good electrical properties.     

Interaction of organolead(IV) derivatives with formyl- and acetylferrocene thiosemicarbazones: Coordination versus dephenylation or reductive elimination processes

The reaction of Ph₂PbCl₂ with formylferrocene and acetylferrocene thiosemicarbazones (HTSCs) in methanol afforded the corresponding adduct [Ph₂PbCl₂(HTSC)₂] or, in one case, the complex [Ph₂PbCl(TSC)]. X-ray crystallography of four of the adducts showed them to be all-trans octahedral complexes with the HTSC ligand S-bound to the metal. The IR spectrum of [Ph₂PbCl(TSC)] suggests that the TSC⁻ ligand is N,S-coordinated. The reaction of Ph₂Pb(OAc)₂ with HTSCs in methanol gave either [Ph₂Pb(OAc)₂(HTSC)₂] or [Ph₂Pb(OAc)(TSC)], which was also obtained from Ph₃Pb(OAc) via a spontaneous dephenylation process. In the former complexes the HTSC ligand is S-coordinated in the solid state. X-ray crystallography of two of the four [Ph₂Pb(OAc)(TSC)] complexes showed that the thiosemicarbazonate anion is N,S-coordinated and the acetate is anisobidentate. Cyclic voltammetry of one [Ph₂PbCl₂(HTSC)₂] adduct and the corresponding [Ph₂Pb(OAc)(TSC)] complex showed that the inductive effect of coordination to lead is transmitted to the ferrocenyl group. Surprisingly, the reaction of Me₂Pb(OAc)₂ with HTSCs afforded only [Pb(TSC)₂] complexes, possibly via redistribution and reductive elimination processes.     

Angle-dependent XPS Analysis of (NH4)2Sx-treated InP(001) Surfaces

Angle-dependent high-resolution XPS spectra of S 2p, In 3d_5/2 and P 2p have been measured on the InP(001) sample etched chemically, treated with (NH₄)₂S _x at room temperature (RT), exposed to air at RT and annealed at 400°C in a vacuum. Three kinds (S-I, S-II and S-III) of chemical states of sulphur on the (NH₄)₂S _x -treated InP(001) surface at RT are found. It is suggested that S-I, S-II and S-III correspond to sulphur in the bulk, sulphur bridge-bonded to indium on the surface and elemental sulphur, respectively. Chemical state of S-III is decreased for the treated sample exposed to air at RT for 1 month. It is removed upon annealing the sample at 400°C in a vacuum, while S-I and S-II remain on the surface. The thickness of the sulphide layer on the annealed surface is estimated to be about one monolayer. Angle-dependent XPS spectra of S 2p and In 3d_5/2 are discussed.