Search results for "Triazine"
showing 10 items of 185 documents
Durability of a strach-based biodegradable polymer
2007
Abstract The photo-oxidation and the photo-stabilization of a commercial biodegradable polymer have been investigated in order to establish the possibility of using this polymer as raw material for films for agriculture. The degradation has been followed by measuring the mechanical properties as a function of photo-oxidation time and in particular by following the elongation at break. The virgin polymer, made from maize starch and a synthetic biodegradable polyester, shows poor resistance to the UV irradiation as observed by the fast decay of the elongation at break, but the presence of small amounts of conventional UV stabilizers strongly improves the durability of this polymer. The UV sta…
Star-Shaped Compounds Having 1,3,5-Triazine Cores
2003
The 1,3,5-triazine derivatives 1−4 having styryl or higher oligo(phenylenevinylene) chains in the 2-, 4-, and 6-positions represent star-shaped push-pull compounds. Alkoxy or dimethylamino groups on the peripheral benzene rings, which act as electron donors, and the central 1,3,5-triazine ring, which acts as an electron acceptor, cause intramolecular charge transfer (ICT) to occur in the absorption S0⇄S1. Protonation of the 1,3,5-triazine core enhances the effect, as demonstrated by a bathochromic shift; a secondary protonation on the dimethylamino groups, however, leads to the breakdown of the ICT. Thus, the yellow compound 1d first becomes violet and then colorless upon the addition of tr…
Mono and dinuclear copper(II) complexes of 2,4,6-tris(2-pyridyl)-1, 3,5-triazine and halide or pseudohalide ions: Synthesis and spectral studies
1986
By inhibiting the copper(II) assisted TPT (TPT = 2,4,6-tris(2-pyridyl)-1,3,5-triazine) hydrolysis, monomeric and dimeric copper(II) complexes having as general formulae Cu(TPT)X, · nH2O (X = Cl, Br, NCS, NCO or N3) and [Cu(TPT)X]2(PF6)2 · nH2O (X = Cl, Br, NCS or N3) have been synthesized and characterized by i.r., electronic and e.p.r. spectra, x-ray powder diffraction and analytical data. Spectroscopic results indicate five-coordinate geometry around the copper(II) ion, intermediate between trigonal-bipyramid and square-pyramid structures. The half-field absorption in the ΔMS = 2 region of powdered X-band e.p.r. spectra has been observed for the dimeric species.
Star-Shaped Push-Pull Compounds Having 1,3,5-Triazine Cores
2006
The 1,3,5-triazines 9–11 having OPV chains in the 2-, 4- and 6-position represent star-shaped compounds which exhibit strong push-pull effects. Their long-wavelength absorption S0 S1 is characterized by an intramolecular charge transfer (ICT) from the dialkylamino group as electron donor D via the conjugated chain to the 1,3,5-triazine core as electron acceptor A. Protonation of the dialkylamino group removes the donor capability, whereas protonation of the 1,3,5-triazine ring enhances the acceptor strength. Thus, the prevailing protonation site has a crucial influence on the push-pull effect and the ICT. The transition energies ΔE (S0 S1) pass through a minimum for the second generation 10…
2-Chlor-4-(dihexylamino)-1,3,5-triazine Herbicides, IV: 2-Chloro-4-(dihexylamino)-1,3,5-triazines
1984
Synthese de derives alkylamino-6 des composes du titre par action d'alkylamines sur la dichloro-2,4 dihexylamino-6 s-triazine
ChemInform Abstract: Metal-Free Regioselective C-C Bond Cleavage in 1,3,5-Triazine Derivatives of β-Diketones.
2014
The reaction of cyanuric chloride (I) with 3 equivalents of ketones (II) in the presence of 3 equivalents of KOH affords adducts (IV), which are converted into deacylated derivatives (III) by treatment with aqueous HCl solution in MeOH.
Synthesis of a new bridgehead nitrogen heterocyclic system. Pyrrolo [2,1-f]-1,2,4-triazine derivatives
1979
1-Ureidopyrroles of type 6a,b prepared by the general method previously described (2), readily cyclized under basic conditions giving pyrrolo [2,1-f]-1,2,4-triazine-2,4(1H, 3H)dione derivatives.
Zentral dämpfende Wirkstoffe, 7. Mitt. Kernsubstituierte (Diallylamino)-1,3,5-triazine
1988
Aus der Umsetzung von 2,4-Dichlor-6-(diallylamino)-1,3,5-triazin (1) mit langkettigen primaren (2a-b) und cyclischen sekundaren (2c-f) Aminen gehen die kernsubstituierten Chlor-diallylamino-1,3,5-triazine (3a-f) hervor. Ein fur Strukturtyp 3 charakteristischer ms Fragmentierungsweg beinhaltet die Umbildung der Diallylaminogruppe zum Aziridinring. Unter den neu entwickelten Verbindungen findet sich zentral dampfende Wirksamkeit besonders in 3a ausgepragt. Daruber hinaus weist Strukturtyp 3 Antiprotozoen-, anthelminthische und insektenwachstumsregulatorische Wirkung auf. CNS Depressants, VII: (Diallylamino)-1,3,5-triazines Substituted at the Triazine Nucleus The reaction of 2,4-dichloro-6-(di…
Gas phase behavior of radical cations of perfluoroalkyl-1,2,4-triazines: an experimental and theoretical study
2009
Electron ionization mass spectrometry and low-energy collision-induced decomposition reactions occurring in a tridimensional ion trap, together with density functional theory (DFT) calculations on neutrals, even- and odd-electron cations, have been used to study the gas-phase ion chemistry of a series of perfluoroalkyl-1,2,4-triazines. Loss of oxygen, due to thermal degradation occurring before ionization, likely involving the hydroxylamino group, has been observed. Compounds having a carbonyl group at position 6 of the triazine ring fragment in the source by elimination of NO followed by HF or CO. The decomposition pathways occurring due to CID experiments have shown interesting features d…
In vitro evolution of an atrazine-degrading population under cyanuric acid selection pressure: Evidence for the selective loss of a 47kb region on th…
2011
International audience; The adaptation of microorganisms to pesticide biodegradation relies on the recruitment of catabolic genes by horizontal gene transfer and homologous recombination mediated by insertion sequences (IS). This environment-friendly function is maintained in the degrading population but it has a cost which could diminish its fitness. The loss of genes in the course of evolution being a major mechanism of ecological specialization, we mimicked evolution in vitro by sub-culturing the atrazine-degrading Pseudomonas sp. ADP in a liquid medium containing cyanuric acid as the sole source of nitrogen. After 120 generations, a new population evolved, which replaced the original on…