Presence Of Different Amines Research Articles

Cu(ii) 3,5-diiodosalicylate complexes: precursor-dependent formation of mono-, di-, tri- and tetranuclear compounds and 1D coordination polymers

Reactions of CuCl2·2H2O or Cu(NO3)2·6H2O with 3,5-diiodosalicylic acid (DISA) in the presence of different amines result in structurally diverse products.

Simple electrochromic sensor for the determination of amines based on the proton sensitivity of polyaniline film

The lack of simple strategies for the design and fabrication of electrochromic (EC) sensors has obstructed the extensive application of these efficient devices in analytical chemistry. Herein, we introduced a novel EC sensor based on the proton sensitivity of conducting polyaniline (PANI) film to determine amines as model analytes. Firstly, the EC behavior of fluorine-doped tin oxide modified with PANI film (FTO/PANI) in both the absence and presence of different amines was studied. The results indicated that amines can interfere with the EC process of PANI. The change in the EC response of PANI at the wavelengths of 420 nm, 620 nm, and 750 nm enables the in-direct determination of amines. It should be emphasized that the absorption spectrum of amines exhibits no peaks in the visible regime. The present method exhibits triethylamine (as an amine) detection in the linear dynamic range of 0.10–7.01 µmol L−1 with a limit of detection of 0.06 µmol L−1. The EC mechanism of PANI towards amines was carefully studied using field emission scanning electron microscope (FESEM), Fourier-transform infrared (FT–IR), X-ray diffraction (XRD), and time-depended density functional theory (TD-DFT) techniques. Finally, as a practical application, the EC sensor was utilized to monitor the spoilage of beef and fish samples in the gaseous phase. The present assay can pave the way for the development of simple and efficient EC sensors.

Synthesis of Zn,Al layered double hydroxides in the presence of amines

ZnAl Layered Double Hydroxides with nitrate as interlamellar anion have been synthesized in the presence of different amines [methylamine (MMA), dimethylamine (DMA) and trimethylamine (TMA)] in the coprecipitation medium. Then, the solids were submitted to hydrothermal post-treatment by conventional heating and microwave assisted heating in order to improve the crystallinity and the properties of the solids. The samples were characterized by element chemical analysis, powder X-ray diffraction, FT-IR spectroscopy, thermal analysis, specific surface area analysis, SEM, and particle size distribution. The results showed an enhancement of their crystallinity when the samples had been synthetized in the presence of DMA, such a crystallinity degree improving after a long hydrothermal treatment. Although aggregates were formed, they disaggregated easily after short ultrasound treatments, and thus it was possible to obtain solid with a narrow particle size distribution.

(Tetrahydrodibenzo[a,i]phenanthridin-5-yl)phenol as a Fluorescent Probe for the Detection of Aniline.

Two (tetrahydrodibenzo[a,i]phenanthridin-5-yl)phenols that differ in their substituents at the para position (P1, R = H and P2, R = NEt2) were designed and synthesized. The presence of a -NEt2 group in probe P2 facilitates the twisted intramolecular charge transfer (TICT) process, making P2 emissive, which distinctly coordinated with boron trifluoride in the presence of different amines with different electronic properties. A substantial increase in emission intensity with increasing viscosity of the surrounding environment and smooth formation of a planar complex with boron and Zn2+ ions concluded the presence of a TICT process. The selective reactivity of P2 toward a tetracoordinated boron complex has been explored as a potential tool for colorimetric and fluorescent discrimination of aromatic primary amines, i.e., anilines. Selective detection of aniline with probe P2 can be viewed through the naked eye, and the corresponding fluorescence turn-on detection limit was found to be 12.65 nM. In addition, the detection of aniline on precoated aluminum-backed thin-layer chromatography plates and Whatman filter paper strips was found to be in good agreement with the color change of P2 in solution and in vapor phase.

Investigation of electroless deposition of cobalt films by EQCM in the presence of different amines

Electroless deposition (also called chemical deposition) is a commonly used chemical approach to prepare metallic layers on various substrates. Cobalt films were deposited on the copper electrode using dimethylamine borane (DMAB) as a reducing agent and different amines: diethylenetriamine (dien), triethylenetetraamine (trien), propylenediamine (prop), tetraethylenepentaamine (ttren), pentaethylenehexaamine (pnten). The deposition conditions of electroless deposition of cobalt films were investigated in more detail by means of electrochemical quartz crystal microgravimetry (EQCM). The effects of pH, temperature and concentration of the reactants on the deposition rate of cobalt films have been determined. It was found that the induction period of the deposition of cobalt films depends on solution composition, temperature, and the presence of different amines.

Multiple functions of amines in the synthesis of anionic, cationic, and neutral indium oxalates

Three new indium oxalates, formulated as H3dpta·In(C2O4)(H2O)3·2SO4 (1), In(qd)(C2O4)1.5·1.5H2O (2), and H2bpp·In2(C2O4)4 (3) in which dpta=dipropylenetriamine, qd=quinoxaline-2,3(1H,4H)-dione, and bpp=1,3-bis(4-piperidyl)propane, were prepared in the presence of different amines. These compounds have cationic, neutral, and anionic frameworks, respectively. Topological analyses reveal that compound 2 has an hcb net, while compound 3 has a dia net. The photoluminescent property of compound 2 was also investigated.

Molecular Organization Induced Anisotropic Properties of Perylene \u2013 Silica Hybrid Nanoparticles

Optically active silica nanoparticles are interesting owing to high stability and easy accessibility. Unlike previous reports on dye loaded silica particles, here we address an important question on how optical properties are dependent on the aggregation-induced segregation of perylene molecules inside and outside the silica nanoparticles. Three differentially functionalized fluorescent perylene - silica hybrid nanoparticles are prepared from appropriate ratios of perylene derivatives and tetraethyl orthosilicate (TEOS) and investigated the structure property correlation (P-ST, P-NP and P-SF). The particles differ from each other on the distribution, organization and intermolecular interaction of perylene inside or outside the silica matrix. Structure and morphology of all hybrid nanoparticles were characterized using a range of techniques such as electron microscope, optical spectroscopic measurements and thermal analysis. The organizations of perylene in three different silica nanoparticles were explored using steady-state fluorescence, fluorescence anisotropy, lifetime measurements and solid state polarized spectroscopic studies. The interactions and changes in optical properties of the silica nanoparticles in presence of different amines were tested and quantified both in solution and in vapor phase using fluorescence quenching studies. The synthesized materials can be regenerated after washing with water and reused for sensing of amines.

Ring Transformation of a 2(3H)‐furanone Derivative into Oxazinone and Pyrimidinone Heterocycles

The conversion of the 2(3H)‐furanone into the oxazinone and pyrimidinone derivatives is studied. A 2‐(furan‐2‐ylmethylene)‐4‐oxo‐4‐phenylbutanoyl azide 3 was synthesized to carry out these conversions through its thermolysis in dry benzene and/or base‐catalyzed decomposition of this azide in the presence of different amines. The structures of all compounds were demonstrated from their spectral data and elemental analyses.

ACCESS TO CONVENIENT SYNTHESIS OF OXAZINONE AND PYRIMIDINONE HETEROCYCLES DERIVED FROM 2(3H)-FURANONE

The conversion of the 2(3 H )-furanone into the oxazinone and pyrimidinone derivatives is studied. A 2-(furan-3-ylmethylene)-4-oxo-4-phenylbutanoyl azide 3 was synthesized to carry out these conversions through its thermolysis in dry benzene and/or base-catalyzed decomposition of this azide in the presence of different amines. The structures of all compounds were demonstrated from their spectral data and elemental analyses.

Brønsted Acid-Catalyzed Dipeptides Functionalization through Azlactones

Azlactones are useful building blocks in the synthesis of functional amino acid derivatives, heterocycles and bioactive molecules. In this work, a protocol for the organocatalytic functionalization of dipeptides has been presented. 2-Alkyl-substituted azlactone intermediates in the presence of different amines and alcohols were combined in a ring opening reaction approach. The products were synthesized in moderate to excellent isolated yields, providing new insights in peptide transformations involving carbodiimide activation.

Octathiotetraphosphetanes—Novel class of biologically active phosphorusorganic compounds: Synthesis, structure, properties

GRAPHICAL ABSTRACT

New method for the synthesis of ammonium salts of O,O'-alkylenedithiophosphoric acid and octathiotetraphosphetane. Crystal structure features's of diethylammonium salt of O,O'-propylenedithiophosphoric acid

GRAPHICAL ABSTRACT

Towards the design of organocatalysts for nerve agents remediation: The case of the active hydrolysis of DCNP (a Tabun mimic) catalyzed by simple amine-containing derivatives

We report herein a study of the hydrolysis of Tabun mimic DCNP in the presence of different amines, aminoalcohols and glycols as potential suitable organocatalysts for DCNP degradation. Experiments were performed in CD3CN in the presence of 5% D2O, which is a suitable solvent mixture to follow the DCNP hydrolysis. These studies allowed the definition of different DCNP depletion paths, resulting in the formation of diethylphosphoric acid, tetraethylpyrophosphate and phosphoramide species as final products. Without organocatalysts, DCNP hydrolysis occurred mainly via an autocatalysis path. Addition of tertiary amines in sub-stoichiometric amounts largely enhanced DCNP depletion whereas non-tertiary polyamines reacted even faster. Glycols induced very slight increment in the DCNP hydrolysis, whereas DCNP hydrolysis increased sharply in the presence of certain aminoalcohols especially, 2-(2-aminoethylamino)ethanol. For the latter compound, DCNP depletion occurred ca. 80-fold faster than in the absence of organocatalysts. The kinetic studies revealed that DCNP hydrolysis in the presence of 2-(2-aminoethylamino)ethanol occurred via a catalytic process, in which the aminoalcohol was involved. DCNP hydrolysis generally depended strongly on the structure of the amine, and it was found that the presence of the OHCH2CH2N moiety in the organocatalyst structure seems important to induce a fast degradation of DCNP.

Electroless Co-B Deposition Using Dimethylamine Borane as Reducing Agent in the Presence of Different Amines

Cobalt films were deposited by electroless metal plating method on the copper electrode. The effects of pH from neutral to acidic solutions, temperature from 50 to 70 oC and concentration of the reactants on the deposition rate were investigated. The induction period of the electroless deposition reaction depends on solution composition, temperature, and the presence of different amines: diethylenetriamine (dien), triethylenetetraamine (trien), propylenediamine (prop), tetraethylenepentaamine (ttren), pentaethylenehexaamine (pnten).

Electroless Co-B Deposition Using Dimethylamine Borane as Reducing Agent in the Presence of Different Amines

The therm “electroless plating” was originally adopted by A. Brenner and G. Riddell [1, 2] to describe a method of plating metal substrates with cobalt or nickel alloys without the benefit of an external source of electric current [3].Electroless metal deposition processes are recognized to be electrochemical by nature and to result from the coupling of two partial electrochemical reactions – the cathodic reduction of metal ions and the anodic oxidation of the reducing agent [4]. Electroless cobalt deposition process is consisting of anodic oxidation of proper reducing agent and cathodic reduction of Co(II) ions occurring simultaneously on the same cobalt surface; the electrons appeared in anodic oxidation of reducing agent are transferred through the metallic surface to adsorbed Co(II) ions, and the autocatalytic deposition of Co takes place. It is noteworthy the fact, that pure cobalt coatings are obtained seldom. In most cases cobalt alloys containing boron or/and phosphorus are formed – phosphorus and boron are originated from reducing agents.When comparing the action of amines on duration of induction period it is seen that in the case of amines with the shorter chain (propylenediamine (prop), diethylenetriamine (dien), triethylenetetraamine (trien)) the induction period is very short and the mixed potential of electrode becomes most negative values also very rapidly. The situation changes dramatically, when using ammines with longer chains and containing more amine-groups (pentaethylenehexaamine (pnten), tetraethylenepentaamine (ttren) ) – the induction period becomes longer: ca. 3 min in the case of pentaethylenehexaamine and more than 6 minutes using tetraethylenepentaamine. The prolongation of induction period is connected with changes in electrode mixed potential values: electroless cobalt deposition begins only when negative enough value of mixed potential is established. It can be noted, that after leveling of quasy-stationary plating conditions, the electroless cobalt deposition rate is practically the same for all amines investigated.Therefore, on the basis of EQCM experiments, we can conclude that the optimum operating conditions (rational low induction period, high enough plating rate and moderate temperature) are as follows: 0.05 M CoSO4, 0.2 M DMAB, amine (preferably diethylenetriamine), pH ca. 6 and temperature of 50 °C. Acknowledgement The work was carried out within the project VP1-3.1-ŠMM-08-K-01-009 that is partly supported by the National Programme “An Improvement of the Skills of Researchers” launched by the Lithuanian Ministry of Education and Science.

Polyamines Are Critical for the Induction of the Glutamate Decarboxylase-dependent Acid Resistance System in Escherichia coli

As part of our studies on the biological functions of polyamines, we have used a mutant of Escherichia coli that lacks all the genes for polyamine biosynthesis for a global transcriptional analysis on the effect of added polyamines. The most striking early response to the polyamine addition is the increased expression of the genes for the glutamate-dependent acid resistance system (GDAR) that is important for the survival of the bacteria when passing through the acid environment of the stomach. Not only were the two genes for glutamate decarboxylases (gadA and gadB) and the gene for glutamate-γ-aminobutyrate antiporter (gadC) induced by the polyamine addition, but the various genes involved in the regulation of this system were also induced. We confirmed the importance of polyamines for the induction of the GDAR system by direct measurement of glutamate decarboxylase activity and acid survival. The effect of deletions of the regulatory genes on the GDAR system and the effects of overproduction of two of these genes were also studied. Strikingly, overproduction of the alternative σ factor rpoS and of the regulatory gene gadE resulted in very high levels of glutamate decarboxylase and almost complete protection against acid stress even in the absence of any polyamines. Thus, these data show that a major function of polyamines in E. coli is protection against acid stress by increasing the synthesis of glutamate decarboxylase, presumably by increasing the levels of the rpoS and gadE regulators.

Green Chemistry. Reaction of Elemental Phosphorus (P4) and Elemental Sulfur with Protonodonor Reagents: New Methods for the Synthesis of Ammonium Salts ofS,S′-Dialkyltetrathiophosphoric Acids and Octathiotetraphosphetane

A new reaction of white phosphorus (P4) with elemental sulfur and thiols in the presence of different amines has been investigated. Ammonium salts of S,S′-dialkyltetrathiophosphoric acids have been observed as main products of the reaction. Octathiotetraphosphetane ammonium salts were formed as side products. The reaction is characterized by a complete conversion of the white phosphorus and is not accompanied by the release of hydrogen sulfide. The crystal structures of both products were determined by the single crystal X-ray diffraction. Biological activity of obtained compounds was investigated, and some promising compounds with antifungal activity identified. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:163–167, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21077

Amine-Templated Anionic Metal–Organic Frameworks with the 4,4′-(Hexafluoroisopropylidene) Bis(benzoic acid) Ligand

Three new compounds with anionic metal–organic frameworks [M3(hfbba)4]2–, M = Mn2+ or Co2+, hfbba = 4,4′-(hexafluoroisopropylidene)bis(benzoic acid), have been synthesized by solvothermal techniques in the presence of different amines. Their structures were determined from single crystal X-ray data. All three structures are based on linear trimers of metal oxide polyhedra. (C6H11NH3)2Mn3(hfbba)4, 1, has a three-dimensional (3D) structure with large cages that are filled by pairs of cyclohexylammonium cations. ((C4H11)2NH2)2Co3(hfbba)4, 2, has a complex layered structure with intralayer lateral channels. One half of the dibutylammonium cations are located inside the channels and are orientationally disordered, while the other half of the dibutylammonium cations are located in the interlayer spaces and are ordered. (H2tdpip)Co3(hfbba)4, 3, tdpip = 4,4′-trimethylenedipiperidine, also has a layered structure with the H2tdpip cations located between the layers. The magnetic properties of compounds 1, 2, and 3 were determined from 10 to 300 K.

Electrostatic Field Force Directed Gold Nanowires from Anion Exchange Resin

We have developed a polarization-induced growth process to synthesize gram quantity of gold nanowire (Au NW) on the outer surface of an anion exchange resin matrix. This new, simple, modified hydrothermolysis (MHT) procedure involving resin-bound HAuCl(4) produced micrometer long Au nanowire on resin surface. The charged resin matrix responsibly imposes electrostatic field effect (EFF) for 1D growth of Au NWs in the presence of different amines or derivatives of amines. The Au nanowire is separated from resin by sonication. Again, the synthesis of MnO(2) nanowire with resin support through similar MHT strengthens the 1D growth proposition, that is, EFF-induced polarization effect.

Photopolymerization kinetics of dimethacrylate‐based light‐cured dental resins

AbstractThe influence of certain factors [structure and concentration of tertiary amines as coinitiators, monomer composition, presence of inorganic pigments, and incident light intensity (I0)] on the polymerization rates (Rp), polymerization quantum yields, and conversions of bisphenol A–bis(glycidyl methacrylate) (Bis‐GMA)/triethylene glycol dimethacrylate based resins was studied. The initial rate of bulk polymerization increased and the final conversion decreased with the content of Bis‐GMA in the mixture. In contrast, it was established that, for all monomer compositions, the Rp grew when increasing the I0, the Rp being directly proportional to the square root of I0. Such behavior is in agreement with the well‐known kinetic expression for the ideal radical photoinitiated polymerization in solution of monofunctional monomers, in spite of the complexity of the dimethacrylate mixtures that were studied. Both the structure and the concentration of reducing amine affected the efficiency of the initiator system and therefore the kinetic behavior of polymerization of these formulations under irradiation. The rate of polymerization increased with the increase of coinitiator concentration over the interval of 0–1%, but later it diminished when increasing the amine content, suggesting that the excess coinitiator retards the polymerization process. The study of the photoreduction of camphorquinone in the presence of different amines showed that the efficiency of the coinitiator depends not only on its ability to photoreduce camphorquinone, forming amine‐derived radicals, but also on the reactivity of these radicals toward the initiation of acrylic monomer polymerization. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1016–1023, 2005