975 resultados para 1,3-BIS(4-PYRIDYL)PROPANE
Resumo:
Thesis (doctoral)--
Resumo:
Thesis (doctoral)--Universitat Rostock.
Resumo:
Thesis (doctoral)--Universität Jena, 1896.
Resumo:
Thesis (doctoral)--Universitat Rostock, 1906.
Resumo:
Thesis (doctoral)--
Resumo:
Thesis (doctoral)--
Resumo:
A rapid one-pot synthesis of 3-alkyl-5-[(Z)-arylmethylidene]-1,3-thiazolidine-2,4-dionesis described that occurs in recyclable ionic liquid [bmim]PF6 (1-butyl-3-methylimidazolium hexafluorophosphate).Significant rate enhancement and good selectivity have been observed.
Resumo:
The thermal decomposition behavior of 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE) widely used as flame retardant plastics additive was studied by HRTG and differential scanning calorimetries. It was pyrolysed in inert atmosphere at 240 and 340 °C in isothermal conditions, the decomposition products were collected and investigated by means of IR and GC-MS, most of them are identified. It was found that BTBPE mostly evaporates at 240 °C. The decomposition products at 340°C depend on rate of their removal from the hot reaction zone. Main primary decomposition products found in case of rapid removal are tribromophenol and vinyl tribromophenyl ether. Whereas, prolonged contact with heating zone also produces hydrogen bromide, ethylene bromide, polybrominated vinyl phenyl ethers and diphenyl ethers, and dibenzodioxins. The nature of the identified compounds are in accordance with a molecular and radical pyrolysis reaction pathway. © 2002 Elsevier Science B.V. All rights reserved.
Resumo:
In analogy to a common synthesis of 1-substituted 5-H tetrazoles (Tetrahedron Lett. 36 (1995)1759; Beloruss. Gos. Univ., Minsk, USSR. Khim. Geterotsikl. Soedin. 11 (1985) 1521; Beloruss. Gos. Univ., Minsk, USSR. Khim. Geterotsikl. Soedin. 1 (1991) 66; BGU, Belarus. Vestsi Akad. Navuk Belarusi, Ser. Khim. Navuk 1 (1992) 73), the new bidentate ligand 1,2-bis(tetrazol-1-yl)ethane [endi] was synthesized and characterized by X-ray diffraction, NMR, IR and UV–Vis spectroscopy. By using iron(II) tetrafluoroborate hexahydrate the complexation with this ligand yields a 1-dimensional linear coordination polymer similar to the recently published chain compound (Inorg. Chem. 39 (2000) 1891) exhibiting a thermally induced spin-crossover phenomenon. Similar to the 1,2-bis(tetrazol-1-yl)propane-bridged compound, our 1,2-bis(tetrazol-1-yl)ethane-bridged compound shows a gradual spin transition, but the spin-crossover temperature T1/2≈140 K is found to be 10 K above the other T1/2. The T1/2 was determined by temperature-dependent 57Fe-Mössbauer, far FT-IR and UV–Vis spectroscopy as well as by temperature-dependent magnetic susceptibility measurements. Single crystals of the complex were grown in situ from a solution of the ligand and iron(II) tetrafluoroborate. The X-ray structure determinations of both the high spin as well as the low spin state of the compound revealed a solid state structure, which is comparable to that of catena-[Fe(1,2-bis(tetrazole-1-yl)propane)3](ClO4)2 (Inorg. Chem. 39 (2000) 1891; 2nd TMR-TOSS Meeting, 4th Spin Crossover Family Meeting, Lufthansa Training Center, Seeheim/Germany, April 30–May 2, 1999). Both the 1,2-bis(tetrazol-1-yl)propane-bridged and our compound do not show a thermal hysteresis effect (J. Am. Chem. Soc. 115 (1993) 9810; Inorg. Chim. Acta 37 (1979) 169; Chem. Phys. Lett. 93 (1982) 567). The synthesis of the complex described in the experimental section yielded a fine powdered product being poorly soluble in most common solvents. The single crystal measurements were done with crystals obtained by various diffusion methods. Most of them yielded either thin needles or small hexagonal prism crystals depending on the specific conditions.