Mechanism,Kinetics and Thermodynamics of Decomposition for High Energy Derivatives of [1,2,4]Triazolo[4,3-b][1,2,4,5]tetrazine

This paper presents the data of research studies on the mechanisms, kinetics and thermodynamics of decomposition of three high-energy compounds: [1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine-3,6-diamine (TTDA), 3-amino-6-hydrazino[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine (TTGA) and 3,6-dinitroamino[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine (DNTT). The points of change of the reaction mechanisms under thermal effects with different intensities from 0.1 to 2000 s⁻¹ have been established. The values of activation and induction energies for the limiting stages of decomposition have been obtained. The formation of nanostructured carbon nitride (α-C₃N₄) in condensed decomposition products, cyanogen (C₂N₂) and hydrogen cyanide (HCN) in gaseous products have been shown. Concentration-energy diagrams for the reaction products have been compiled. The parameters of heat resistance and thermal safety proved to be: 349.5 °C and 358.2 °C for TTDA; 190.3 °C and 198.0 °C for TTGA; 113.4 °C and 114.1 °C for DNTT. The energy and thermodynamic properties have also been estimated. This work found the activation energy of the decomposition process to be 129.0 kJ/mol for TTDA, 212.2 kJ/mol for TTGA and 292.2 kJ/mol for DNTT. The average induction energy of the catalytic process (Ecat) for TTGA was established to be 21 kJ/mol, and for DNTT-1500–1700 kJ/mol. The induction energy of the inhibition process (Eing) of TTDA was estimated to be 800–1400 kJ/mol.     

Rapid Full-Cycle Technique to Control Adulteration of Meat Products: Integration of Accelerated Sample Preparation,Recombinase Polymerase Amplification,and Test-Strip Detection

Verifying the authenticity of food products is essential due to the recent increase in counterfeit meat-containing food products. The existing methods of detection have a number of disadvantages. Therefore, simple, cheap, and sensitive methods for detecting various types of meat are required. In this study, we propose a rapid full-cycle technique to control the chicken or pig adulteration of meat products, including 3 min of crude DNA extraction, 20 min of recombinase polymerase amplification (RPA) at 39 °C, and 10 min of lateral flow assay (LFA) detection. The cytochrome B gene was used in the developed RPA-based test for chicken and pig identification. The selected primers provided specific RPA without DNA nuclease and an additional oligonucleotide probe. As a result, RPA–LFA, based on designed fluorescein- and biotin-labeled primers, detected up to 0.2 pg total DNA per μL, which provided up to 0.001% w/w identification of the target meat component in the composite meat. The RPA–LFA of the chicken and pig meat identification was successfully applied to processed meat products and to meat after heating. The results were confirmed by real-time PCR. Ultimately, the developed analysis is specific and enables the detection of pork and chicken impurities with high accuracy in raw and processed meat mixtures. The proposed rapid full-cycle technique could be adopted for the authentication of other meat products.     

Modulation of Metallophilic and π–π Interactions in Platinum Cyclometalated Luminophores with Halogen Bonding

Luminescent cyclometalated complexes [M(C^N^N)CN] (M=Pt, Pd; HC^N^N=pyridinyl- (M=Pt 1 , Pd 5 ), benzyltriazolyl- (M=Pt 2 ), indazolyl- (M=Pt 3 , Pd 6 ), pyrazolyl-phenylpyridine (M=Pt 4 )) decorated with cyanide ligand, have been explored as nucleophilic building blocks for the construction of halogen-bonded (XB) adducts using IC₆F₅ as an XB donor. The negative electrostatic potential of the CN group afforded CN⋅⋅⋅I noncovalent interactions for platinum complexes 1 – 3 ; the energies of XB contacts are comparable to those of metallophilic bonding according to QTAIM analysis. Embedding the chromophore units into XB adducts 1 – 3 ⋅⋅⋅IC₆F₅ has little effect on the charge distribution, but strongly affects Pt⋅⋅⋅Pt bonding and π-stacking, which lead to excited states of MMLCT (metal–metal-to-ligand charge transfer) origin. The energies of these states and the photoemissive properties of the crystalline materials are primarily determined by the degree of aggregation of the luminophores via metal–metal interactions. The adduct formation depends on the nature of the metal and the structure of the metalated ligand, the variation of which can yield dynamic XB-supported systems, exemplified by thermally regulated transition 3 ↔ 3 ⋅⋅⋅IC₆F₅.     

Destruction of 2,4 Dichlorophenol in an Atmospheric Pressure Dielectric Barrier Discharge in Oxygen

The processes of degradation of 2,4-dichlorophenol (2,4-DCP) under the action of atmospheric pressure of dielectric barrier discharge (DBD) in oxygen were studied. It was shown that the degradation of 2,4-DCP proceeds efficiently. Degree of decomposition reaches 90%. The degradation kinetics of 2,4-DCP obeys the formal first-order kinetic law on concentration of 2,4-DCP. The effective rate constants depend weakly on the experimental conditions and are equal to ~0.2 s^?1. Based on experimental data, the energy efficiency of decomposition of 2,4-DCP was determined. Depending on the conditions, the energy efficiency was in the range of (8–90) × 10^?3 molecules per 100 eV. The composition of the products was studied by gas chromatography (GC), gas chromatography–mass spectrometry (GC–MS), energy-dispersive X-ray spectroscopy (EDX), attenuated total reflection-fourier transform infrared (ATR-FTIR) spectroscopy, electron spin resonance (ESR) spectroscopy and UV/Visible spectroscopy. It was shown that about ~20% of 2,4-DCP is converted to CO₂, while the other part forms an organic film on the reactor wall. The substance formed is close to the carboxylic acids in chemical composition and exhibits electrical conductivity and paramagnetic properties. Almost all of the chlorine contained in the 2,4-DCP is released into the gas phase. The active species of the afterglow react with liquid hexane, forming the products of its oxidation. Some assumptions regarding the pathway of the process are discussed.     

Synthesis of chiral allyltitaniums having an amino group at the C-4 position and their diastereoselective addition reaction with aldehydes

Chiral allyltitaniums having an amino substituent at the C-4 position are prepared from optically active allylic alcohol derivatives 1 and a Ti(O-i-Pr)₄/2i-PrMgCl reagent, which, in turn, react with aldehydes regio- and stereoselectively to afford 3-amino-2-vinylalkanols in excellent yields.     

Synthesis of (4-nitro-1H-indol-6-yl)- and (4-amino-1H-indol-6-yl)phosphonic acid derivatives

Chemistry of Heterocyclic Compounds - A convenient methodology for the synthesis of previously unreported (1H-indol-6-yl)phosphonic acid derivatives has been described. Reaction of...     

Investigation of intermolecular interactions in solution polymer‐organic dye by method electronic spectroscopy

It has been shown that specific electrostatic interactions between charges of ion dyes and functional groups of polymer play main role in the cause of polar coulored matrices. These interaction prevent by formation tight ion pairs of dyes and their associates. Therefore, such matrices have practically the same electronic spectra as liquid solution of dyes. Electrostatic interactions between dye counterions dominate in low polarity polymer matrices. Process of formation tight ions pair is became easier. Such pairs cause quenching of the fluorescence and distortion of electronic spectra by comparison with liquids.     

Synthesis of novel 1,3‐substituted 1H‐[1,2,4]‐triazole‐3‐thiol derivatives

By means of regioselective S‐alkylation of 1H‐1,2,4‐triazole‐3‐thiol ( 1 ), a series of S‐substituted derivatives 2a‐j were synthesized. In certain conditions, the reaction of 2 with arylsulfochlorides, arylisocyanates, and quaternary ammonium salts of azines corresponding compounds were obtained 1‐arylsulfonyl‐ (3a‐d) , 1‐arylcarbonamido‐ ( 4a,b ), and 1‐azinyl‐1,2,4‐ ( 6a‐p ) triazoles. Structures of compounds were confirmed by ¹H NMR and elemental analyses. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 20:405–410, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20565     

A route to fluorocontaining N,S-heterocycles via octafluoro-2,3-epoxybutane

The reaction of octafluoro-2,3-epoxybutane 1 with 2-aminothiophenol gave three kinds of novel fluorocontaining N,S-heterocyclic compounds depending on the solvent nature: 2,3-bis(trifluoromethyl)-3,4-dihydro-2H-1,4-benzothiazin-2-ol 2, 2-trifluoromethyl-2-[1-(2-aminophenylthio)-2,2,2-trifluoroethyl]-1,3-benzothiazolidine 6 and 5a,11a-bis(trifluoromethyl)-5a,6,11a,12-tetrahydro-5,11-dithia-6,12-diazanaphthacene 5. Use of the toluene, dioxane, tetrahydrofuran, acetonitrile and dimethoxyethane gave the unexpected dihydrobenzothiazine 2 (RS,SR > RR,SS) in good to moderate yields. In dimethylsulfoxide and N,N-dimethylacetamide, unusual cyclization occurred resulting in benzothiazolidine 6 (RS,SR/RR,SS ∼ 1:1) in moderate yields. Formation of minor 1,1,1,3,4,4,4-heptafluoro-3-(2-aminophenylthio)-2,2-dihydroxybutane 4 which was converted into bis(benzothiazine) 5 was observed in all solvents tested with the exception of toluene and dioxane. The molecular structure of the RS,SR-diastereomer of dihydrobenzothiazine 2, bis(benzothiazine) 5 and the RS,SR-diastereomer of benzothiazolidine 6 has been established by X-ray crystallography.     

Expanded‐Ring N‐Heterocyclic Carbenes Efficiently Stabilize Gold(I) Cations,Leading to High Activity in π‐Acid‐Catalyzed Cyclizations

A series of six‐ and seven‐membered expanded‐ring N‐heterocyclic carbene (er‐NHC) gold(I) complexes has been synthesized using different synthetic approaches. Complexes with weakly coordinating anions [(er‐NHC)AuX] (X^?=BF₄^?, NTf₂^?, OTf^?) were generated in solution. According to their ¹³C NMR spectra, the ionic character of the complexes increases in the order X^?=Cl^?<NTf₂^?<OTf^?<BF₄^?. Additional factors for stabilization of the cationic complexes are expansion of the NHC ring and the attachment of bulky substituents at the nitrogen atoms. These er‐NHCs are bulkier ligands and stronger electron donors than conventional NHCs as well as phosphines and sulfides and provide more stabilization of [(L)Au⁺] cations. A comparative study has been carried out of the catalytic activities of five‐, six‐, and seven‐membered carbene complexes [(NHC)AuX], [(Ph₃P)AuX], [(Me₂S)AuX], and inorganic compounds of gold in model reactions of indole and benzofuran synthesis. It was found that increased ionic character of the complexes was correlated with increased catalytic activity in the cyclization reactions. As a result, we developed an unprecedentedly active monoligand cationic [(THD‐Dipp)Au]BF₄ (1,3‐bis(2,6‐diisopropylphenyl)‐3,4,5,6‐tetrahydrodiazepin‐2‐ylidene gold(I) tetrafluoroborate) catalyst bearing seven‐membered‐ring carbene and bulky Dipp substituents. Quantitative yields of cyclized products were attained in several minutes at room temperature at 1 mol % catalyst loadings. The experimental observations were rationalized and fully supported by DFT calculations.