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101.
Iron,nickel and zinc malates coordination compounds cynthesis,characterization and thermal behaviour
Patron L. Carp O. Mindru I. Marinescu G. Segal E. 《Journal of Thermal Analysis and Calorimetry》2003,72(1):281-288
The coordinations compounds (NH4)[Fe(C4H4O5)(OH)2]·0.5H2O, [Ni(C4H4O5)]·3H2O and [Zn(C4H4O5)]·5H2O were synthesized by a precipitation method and characterized by chemical analysis, spectral (IR, UV-VIS) and magnetical
investigations. In the range 50-600°C stepped thermal decompositions occur with formation of anhydrous malates, malonates,
oxoacetates (iron and nickel compounds) and hydroxocarbonate (Zn compound) as intermediates observed by FT-IR spectroscopy.
α-Fe2O3, NiO and ZnO constitute the final decomposition products.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
102.
L. Patron G. Marinescu D. Culita L. Diamandescu O. Carp 《Journal of Thermal Analysis and Calorimetry》2008,91(2):627-632
The thermal stability of two amino acid-(tyrosine and tryptophan) coated magnetite and their corresponding precursors, [Fe2IIIFeII(Tyr)8]·9H2O and [Fe2IIIFeII(Trp)2(OH)4](NO3)2·8H2O (where tyrosine=Tyr and tryptophan=Trp), was analyzed in comparison with free amino acids. The complexes present a lower
thermal stability relative to the free ligand, due to the catalytic effect introduced by the iron cation and the presence
of NO3− groups. The presence of NO3− group determines also a different degradation’s stoichiometry of the amino acid anion comparative with the one expressed
by the free ligand molecule. The amino acid bonded to magnetite decomposes in two steps, its presence inducing an increasing
of γ-Fe2O3→Fe2O3 conversion temperature. 相似文献
103.
Radu‐Dan Rusu Mariana‐Dana Damaceanu Luminita Marin Maria Bruma 《Journal of polymer science. Part A, Polymer chemistry》2010,48(19):4230-4242
New copolyimides containing perylenediimide, oxadiazole and hexafluoroisopropylidene moieties were prepared by one‐step polycondensation reaction in solution at high temperature of aromatic diamines containing preformed oxadiazole ring with a mixture of a dianhydride having a perylene ring and another dianhydride with hexafluoroisopropylidene unit. The thermal stability and glass transition temperatures of these copolyimides were measured and compared with those of related polyimides. The solid polymers were also studied by polarized light microscopy and X‐ray diffraction which revealed a semicrystalline state consisting of face‐to‐face arranged columns of perylenediimide units. The film‐forming ability and properties of the resulting thin films were investigated by using atom force microscopy and scanning electron microscopy which showed that the films were organized into self‐assembled rod‐like structures. The UV‐Vis and photoluminescence properties in solution and in solid state were also investigated. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4230–4242, 2010 相似文献
104.
A series of new azomethine dimers was synthesized by the condensation reaction of flexible bis-benzaldehydes with four aromatic amines containing phenyl, naphthyl, anthracene and pyrene groups. Their right structure was confirmed by FTIR and 1H-NMR spectroscopy and their thermal properties were investigated by thermogravimetric analysis, differential scanning calorimetry and polarized light optical microscopy. A view on their photophysical behavior was gained by UV-vis and photoluminescence spectroscopy. The dimers containing pyrene and anthracene presented liquid crystalline behavior, while the other dimers were crystalline compounds. Two dimers containing pyrene moieties formed mesomorphic glasses and had intense luminescence, promising properties for applications in building optoelectronic devices. 相似文献
105.
106.
Luiza Găină Emese Gal Larisa Mătărângă-Popa Dan Porumb Alina Nicolescu Castelia Cristea Luminita Silaghi-Dumitrescu 《Tetrahedron》2012,68(11):2465-2470
Comparison studies on the acetalization of 10-methyl-10H-phenothiazine-carbaldehyde with 1,3-propanediol, or 2-substituted-1,3-propanediols, under conventional versus microwave assisted conditions and standard organic solvents versus water, were performed as an attempt toward more environmentally benign synthetic methods. New 3-(1,3-dioxan-2-yl)-10-methyl-10H-phenothiazine derivatives were obtained in high yields by azeotropic distillation of water and in moderate yields by microwave assisted synthesis in different solvents, including water under superheated conditions. The solvent influence upon stabilizing the key intermediates involved in the acetalization mechanism was assumed based on DFT calculations, which indicated a favorable enthalpy profile in water solvent. Structural investigations of the new compounds based on spectroscopic methods (NMR, FT-IR, UV–vis, and MS), were completed with molecular mechanics and semi-empirical DFT calculations, which supported an anancomeric chair conformation of the 1,3-dioxane ring with the phenothiazine substituent in the equatorial position and possible free rotation about the single bond linking the two heterocyclic units. The new compounds display daylight fluorescence characterized by remarkably large Stokes shifts determined by LE spectroscopy. 相似文献
107.
Walter Keung Farid Bakir Andrew P. Patron Dan Rogers Chad D. Priest Vincent Darmohusodo 《Tetrahedron letters》2004,45(4):733-737
α-Amino amidines are made via a novel scandium(III) triflate catalyzed multi-component reaction involving aldehydes, amines, and isonitrile. The reaction can be automated and is amenable to library production. The chemistry of α-amino amidine described herein can be elaborated further for the synthesis of hydantoin imides and imidopyrazine derivatives. 相似文献
108.
109.
Adriana Samide B. Tutunaru Catalina Ionescu P. Rotaru Luminita Simoiu 《Journal of Thermal Analysis and Calorimetry》2014,118(2):631-639
Aminophylline (AMF) was studied as corrosion inhibitor for carbon steel in 1.0 mol L?1 HCl solution using electrochemical measurements associated with UV–Vis spectrophotometry and optical microscopy. Simultaneous thermogravimetry/derivative thermogravimetry and differential scanning calorimetry analysis was performed in order to determine the temperature range in which AMF is an effective inhibitor, without the decomposition risk that could change the inhibition mechanism. Thermal behaviour restricts AMF application as corrosion inhibitor for carbon steel in 1.0 mol L?1 HCl solution at temperatures ≤45 °C where there are no significant modifications of the adsorption mechanism. According to the results of electrochemical measurements, in association with UV–Vis spectrophotometry and optical microscopy techniques, AMF is a mixed-type inhibitor for carbon steel corrosion in 1.0 mol L?1 HCl solution, simultaneously suppressing the anodic and cathodic processes and acting via spontaneous physisorption on the metal surfaces. 相似文献
110.
Mihaela Badea Ioana Dorina Vlaicu Rodica Olar Madalina Constand Coralia Bleotu Mariana Carmen Chifiriuc Luminita Marutescu Veronica Lazar Maria Nicoleta Grecu Dana Marinescu 《Journal of Thermal Analysis and Calorimetry》2014,118(2):1119-1133
Four coordination compounds of copper(II) were synthesised and characterised in solid state by elemental analysis, infrared, electronic and EPR spectroscopy, as well as by thermal analysis (TG/DTA). The complexes were formulated on the basis of experimental data as: [Cu(BzIm)2(H2O)]·H2O (1), [Cu2(Acr)4(HBzIm)2] (2), [Cu(Acr)2(HBzIm)2] (3) and [Cu(Acr)2(HBzIm)2(H2O)]·H2O (4). IR data are in accordance with the unidentate nature of benzimidazole, in complexes (2), (3) and (4), and bridge bidentate nature of benzimidazole, in complex (1), while acrylato acts as uni- or bridge/chelate ligand. The electronic spectra display the characteristic pattern of square planar, square pyramidal, or octahedral stereochemistry, also confirmed by EPR spectra. Thermal decomposition evidenced several well-defined steps as dehydration of complexes (1) and (4), benzimidazole molecule releases for all complexes and acrylate decomposition in carbonate for complexes (3) and (4). In all four cases, the final residue after thermal treatment in air flow is copper(II) oxide, formed during the decomposition steps for complexes (3) and (4), and, respectively, after the oxidation of the metallic copper for complexes (1) and (2). Antimicrobial activities of the complexes have been determined by in vitro assays, against various Gram-negative and Gram-positive bacterial and fungal strains. Copper(II) complexes were also evaluated for their cytotoxicity on eukaryotic cells. 相似文献