Structure, thermal behavior, and IR investigation of a new organic sulfate

[1-(2-ammoniumethyl) piperazinium] sulfate denoted PIPS has a monoclinic unit cell. The parameters are: a = 6.6521(3), b = 7.8756(5), c = 19.197(1) Å, = 94.43(1)° and the space group is P2₁/n. The preparation, thermal analysis, and IR spectrometric investigation are described. The PIPS structure exhibits a complex three-dimensional network of H-bonds connecting all its components.     

AgNi3(PO4)(HPO4)2: an alluaudite‐like structure

The new title phosphate, silver trinickel phosphate bis(hydrogenphosphate), has been synthesized by the hydro­thermal method. It has an alluaudite‐like structure but shows some differences owing to the presence of the H atoms. The structure is isomorphous with the compounds of general formula AM₃(XO₄)(HXO₄)₂ (A is Na or Ag, M is Co, Zn or Mn, and X is As or P), with the Ag atom, one Ni atom and one P atom lying on twofold axes.     

Synthesis and structural characterization of the dinuclear tetrakis(guanidino) bis(2-cyanoguanidine)dicopper(II) complex

The synthesis and crystal structure of a new dinuclear complex Cu₂(C₂H₄N₄)₂ (CH₃N₃)₄ are reported. It crystallizes in the monoclinic system of space group P2₁/c, with a = 8,459(1) Å, b = 15,481(3) Å, c = 8,714(2) Å, = 110,60(1)°, and Z = 2. The centrosymmetric molecular structure of Cu₂(C₂H₄N₄)₂(CH₃N₃)₄ comprises a tetrakis(guanidino)-bridged dinuclear copper(II) core with axially located cnge moities.     

Structure, thermal behavior, and IR investigations of (C6H9N2)H2PO4

Chemical preparation, X-ray single-crystal, thermal behavior, and IR spectroscopy studies of a new dihydrogenmonophosphate associated to an organic cation, the 3-(ammoniummethyl)pyridine dihydrogenmonophosphate (denoted as AMPP) are described. The AMPP crystallizes in the monoclinic system with P2₁/c space group. The unit cell dimensions are a = 5.8465(2) Å, b = 19.9776(9) Å, c = 7.3103(3) Å, = 90.848(3)° with V = 853.74(4) ų and Z = 4. The structure has been solved using direct method and refined to a reliability R factor of 0.0393. The structure of AMPP includes three types of hydrogen bonds. The first one, O H O, links the H₂PO₄ groups to form infinite inorganic chains [H₂PO₄]n ^n–, parallel to the c axis. The two other types, O H N and N H O assemble inorganic chains so as to build up a three-dimensional arrangement.     

Structure, thermal behavior, and IR investigation of bis(3-amino-1,2,4-triazolium)monohydrogen monophosphate

Chemical preparation, calorimetric studies, crystal structure, and IR spectrometric investigation of (C₂H₅N₄)₂HPO₄, denoted ATZP, are described. The compound crystallizes in the monoclinic system with C2/c space group. Its unit cell dimensions are a = 13.589(2) Å b = 11.105(2) Å c = 15.734(3) Å = 104.68(2)°, V = 2296.8(7) ų, and Z = 8. The structure of the title compound consists of a three dimensional network of H-bonds connecting all its components. The IR spectrum of ATZP is reported and discussed on the basis of group theoretical analysis.     

Crystal structure, thermal analysis, and IR spectrometric investigation of bis(tert-butylammonium) sulfate

Chemical preparation, X-ray single crystal, thermal analysis, and IR spectrometric investigation of (C₄H₁₂N)₂SO₄, denoted tBAS, are described. The compound crystallizes in the monoclinic system with C2/c space group. Its unit cell dimensions are a = 11.1585(5) Å, b = 6.2148(4) Å, c = 20.070(1) Å, = 102.004(4)°, V = 1361.4(1) ų, and Z = 4. The crystal structure of tBAS can be described as a typical thick layered organization built by all the components of the structure and centered by planes z = 1/4 and 3/4. Connection in these layers are established by N—H···O hydrogen bonds. Thermal analysis shows a reversible weak phase transition.     

Equilibrium diagram of KPO3–Y(PO3)3 system, chemical preparation and characterization of KY(PO3)4

Microdifferential thermal analysis (μ-DTA), X-ray diffraction (XRD) and infrared (IR) spectroscopy were used for the first time to investigate the liquidus and solidus relations in the KPO₃–Y(PO₃)₃ system. The only compound observed within the system was KY(PO₃)₄ melting incongruently at 1033 K. An eutectic appears at 13.5 mol% Y(PO₃)₃ at 935 K, the peritectic occurs at 1033 K and the phase transition for potassium polyphosphate KPO₃ was observed at 725 K. Three monoclinic allotropic phases of the single crystals were obtained. KY(PO₃)₄ polyphosphate has the P2₁ space group with lattice parameters: a=7.183(4) Å, b=8.351(6) Å, c=7.983(3) Å, β=91.75(3)° and Z=2 is isostructural with KNd(PO₃)₄. The second allotropic form of KY(PO₃)₄ belongs to the P2₁/n space group with lattice parameters: a=10.835(3) Å, b=9.003(2) Å, c=10.314(1) Å, β=106.09(7)° and Z=4 and is isostructural with TlNd(PO₃)₄. The IR absorption spectra of the two forms show a chain polyphosphates structure. The last modification of KYP₄O₁₂ crystallizes in the C2/c space group with lattice parameters: a=7.825(3) Å, b=12.537(4) Å, c=10.584(2) Å, β=110.22(7)° and Z=4 is isostructural with RbNdP₄O₁₂ and contains cyclic anions. The methods of chemical preparations, the determination of crystallographic data and IR spectra for these compounds are reported.     

New confined p-phenylenevinylene (PPV)-type polymer analogue of poly(phenylene sulfide)

A new confined p-phenylenevinylene (PPV)-type polymer (PPVS) has been synthesized using Wittig condensation. The chemical structure of the polymer was well defined by ¹H NMR, ¹³C NMR, and FTIR spectroscopic analysis. PPVS contains oligomeric PPV units separated by sulfide bridges in the main chain; it is fully soluble in common organic solvents and has a number-average molecular weight of 3500 g mol⁻¹. Thermogravimetric analysis and differential scanning calorimetry indicate that PPVS is amorphous, stable up to 360 °C in air and displays a glass transition temperature of 98 °C. The optical properties of the polymer were investigated by UV-visible absorption and photoluminescence spectroscopies. The polymer film absorbs at 375 nm and emits at 517 nm with a narrow emission spectrum. From the cyclic voltammetry analysis, the electrochemical bandgap was estimated to be 2.78 eV. A single-layer diode device of the configuration indium-tin oxide/PPVS/aluminium has been fabricated and has a relatively low turn-on voltage of 3.4 V. An electroluminescent emission similar to photoluminescence is demonstrated in a multilayer device.     

Crystal structure,thermal analysis and IR spectroscopy investigations of N,N‐dimethyl‐1,3‐propanediammonium monohydrogenmonophosphate trihydrate

A new organic monohydrogenmonophosphate (C₅H₁₆N₂)HPO₄.3H₂O (abbreviate as MPAP) is prepared by reacting H3PO4 with N, N‐dimethyl‐1,3‐propanediamine. This compound crystallizes in the orthorhombic crystal system, space group Pca2₁. Unit cell parameters are a % 8.1445(1) Å, b % 11.7734(2) Å, c % 12.9021(2) Å, with, Z % 4 and ρ_m % 1.31 g cm⁻³. The structure was solved, using the direct methods and refined against F² to a reliability R factor of 0.0257. Three types of hydrogen bonds participate to the structural cohesion: O(P)—H…O, O(W)—H…O and N—H…O. The first one connects HPO₄ groups in infinite chains. This organization of the phosphoric groups creates voids in which are located the water molecules which are themselves connected by the second type of hydrogen bonds to the adjacent phosphoric groups that lead to a typical layer organization of a polyanion [HPO₄.(H₂O)₃ ]²ⁿ⁻_n. The third hydrogen bond type is responsible for the cohesion between the two‐dimensional polyanions. Thus, a framework in a threedimensional way is then created. The thermal decomposition of MPAP shows a large endothermic effect corresponding to the elimination of the water molecules and a set of endotherms which are probably due to the evolution of ammonia from the structure and the decomposition. The title compound was also characterized by IR spectroscopy, the interpretation of the spectra is based on theoretical analyses and literature data. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Characterization of Primary Action Mode of Eight Essential Oils and Evaluation of Their Antibacterial Effect against Extended-Spectrum β-Lactamase (ESBL)-Producing Escherichia coli Inoculated in Turkey Meat

The current study aims to evaluate the antimicrobial activity of eight essential oils (EOs) against multidrug-resistant Escherichia coli strains, producing extended-spectrum β-lactamase (ESBL) enzymes and isolated from foods. Disc-diffusion assay showed that the inhibition diameters generated by EOs varied significantly among the tested EOs and strains. In fact, EOs extracted from Thymus capitaus, Eucalyptus camaldulensis, Trachyspermum ammi and Mentha pulegium exerted an important antimicrobial effect against tested strains, with the diameters of inhibition zones varied between 20 and 27 mm. Moreover, minimal inhibition and bactericidal concentration (MIC and MBC) values demonstrated that T. capitatus EOs generate the most important inhibitory effect against E. coli strains, with MIC values ranging from 0.02 to 0.78%. Concerning the mode of action of T. capitatus EO, the obtained data showed that treatment with this EO at its MIC reduced the viability of E. coli strains, their tolerance to NaCl and promoted the loss of 260-nm-absorbing material. In addition, in the presence of T. capitatus EO, cells became disproportionately sensitive to subsequent autolysis. Moreover, the inhibitory effect of T. capitatus was evaluated against two E. coli strains, experimentally inoculated (10⁵ CFU/g) in minced turkey meat, in the presence of two different concentrations of EO (MIC and 2 × MIC), and stored for 15 days. In both samples, EO exerted a bacteriostatic effect in the presence of concentrations equal to MIC. Interestingly, at 2 × CMI concentration, the bactericidal activity was pronounced after 15 days of storage. Our results highlighted that the use of essential oils, specially of T. capitatus, to inhibit or prevent the growth of extended-spectrum β-lactamase (ESBL)-producing E. coli in food, may be a promising alternative to chemicals.