6912-12-5Relevant articles and documents
7Pb4X15 (X = Cl- and Br-), 2D-Perovskite Related Hybrids with Dielectric Transitions and Broadband Photoluminiscent Emission
García-Fernández, Alberto,Bermúdez-García, Juan Manuel,Castro-García, Socorro,Llamas-Saiz, Antonio Luis,Artiaga, Ramón,López-Beceiro, Jorge José,Sánchez-Andújar, Manuel,Se?arís-Rodríguez, María Antonia
, p. 3215 - 3222 (2018)
We have prepared two new lead halides with the novel general formula of DMA7Pb4X15 (DMA = [(CH3)2NH2]+ and X = Cl- or Br-) by using an easy route under mild conditions at room temperature. These compounds exhibit an unprecedented crystal structure, are formed by layers of distorted [PbX6] octahedra, which share corners and faces, and contain intercalated DMA cations. Very interestingly, they display dielectric transitions, which are related to a partial order-disorder process of the DMA cations between 160 and 260 K. Additionally, these new layered hybrids exhibit a broadband photoluminiscent emission, which is related to the structural distortions of the [PbX6] octahedra. These findings not only open up large possibilities for future optoelectronic applications of these materials, but they also offer a novel playground for an easy modulation of electrical and optical properties of hybrid organic-inorganic materials. We anticipate that this novel A7Pb4X15 formula can be adequate to tune the family of the hybrid lead halides using other alkylammonium cations, such as methylammonium, formamidinium, or ethylammonium, to improve their photoelectronic properties.
Reaction of N,N,N′,N ′-tetramethyloxamide with bromine
Kanibolotskii,Mikhailov,Savelova
, p. 198 - 201 (2001)
Reaction of bromine with N,N,N′,N′-tetramethyloxamide results in dibromobromate of 3-methyl-5-dimethylimmoniooxazolidin-4-one (in an open system) and in dibromobromate of 4,5,-dibromo-1,3-dimethylimidazolium (in a closed system).
Di-, tri-, and tetra(pentafluorophenyl) derivatives for oligotopic anion-π interactions
Giese, Michael,Albrecht, Markus,Steike, Simon,Ackermann, Anton,Valkonen, Arto,Rissanen, Kari
, p. 7666 - 7672 (2013/07/26)
The present study describes a series of pentafluorobenzyl ammonium salts with two, three, or four C6F5 units in order to investigate simultaneous interactions of several perfluorinated arenes with anions in the crystalline state. Most of the structures show multiple anion-π contacts. However, only 6·2HI reveals an effective encapsulation of the iodide ion by the aromatic units. For comparison, the structure of 4b is investigated because it offers two π-systems with inverse charge distribution to a bromide anion. Only the electron-deficient π-system of the pentafluorophenyl group interacts with the anion.
Photodegradative surfactants: p-dodecylbenzyltrimethylammonium bromide as a photodegradative emulsifier for microemulsion polymerization
Itoh, Yoshihiro,Horiuchi, Satoshi,Yamamoto, Kenji
, p. 814 - 815 (2007/10/03)
A photodegradative surfactant, p-dodecylbenzyltrimethylammonium bromide, was used as an emulsifier for micro-emulsion polymerization of methyl methacrylate in water. The resulting polymer latex was coagulated during UV irradiation. The analysis of the centrifuged solid after irradiation indicated almost perfection of both recovery of the polymer and removal of surface-active species from it. Copyright
Photodegradative surfactants: Photolysis of p-dodecylbenzyltrimethylammonium bromide in aqueous solution
Itoh, Yoshihiro,Yamamoto, Kenji,Shirai, Hirofusa
, p. 8 - 9 (2007/10/03)
Upon UV irradiation, a benzyl-containing cationic surfactant, p-dodecylbenzyltrimethylammonium bromide, has been converted to a nonsurfactant, which can be separated from the aqueous solution by coprecipitation with CaSO4.
Further studies on the substitutional behavior of 1,2-Mo2Br2(CH2SiMe3)4. Alkyl, amide, phosphide, alkoxide, and thiolate for bromide exchange and isomerizations of 1,1- and 1,2-Mo2X2(CH2SiMe3)4 compounds
Chisholm, Malcolm H.,Click, Damon R.,Huffman, John C.
, p. 3916 - 3924 (2008/10/08)
Reactions involving 1,2-Mo2Br2(CH2SiMe3)4 and each of LiNMe2 and HNMe2 in hexane at -50 °C proceed to give 1,1′-Mo2(NMe2)BrR4, where R = CH2SiMe3, as the first product of Br for amide exchange at the Mo26+ center. Further substitution in reactions with LiNMe2 gives 1,1-Mo2(NMe2)2R4, but with HNMe2 the 1,2-Mo2(NMe2)2R4 isomer is formed. These two do not interconvert thermally (>100 °C) and undergo aminolysis (HNMe2-d6) and alcoholysis (tBuOH) with retention of regiochemistry. 1,1- to 1,2-isomerization of Mo2(NMe2)2R4 is catalyzed by the presence of Me2NH2Br. The mechanisms of these metathetic reactions are discussed in terms of plausible pathways that may promote alkyl group migration across the Mo triple bond Mo bond. Further studies of the bromide substitution by alkyl, aryl, alkoxide, thiolate, and phosphide ligands are described for 1,1′-Mo2(NMe2)BrR4 and 1,2-Mo2Br2R4. The new compounds of formula Mo2(NMe2)YR4 (Y = CH2SiMe3, Ph, OtBu, OiPr, StBu, PPh2, and Br) and Mo2(StBu)2R4 have been characterized by variable-temperature 1H and 13C{1H} NMR spectroscopy and mass spectrometry and for Y = PPh2 by single-crystal X-ray crystallography.
Studies of Heterocyclic Compounds. Part 31. 4-Alkyl-5-alkylimino-Δ2-1,2,4-thiadiazolines: Synthesis and Cycloaddition Reactions with Nitriles in Attempts to Prepare 3aλ4-Thia-1,3,4,6-tetraazapentalenes
Lai, Long-Li,Ngoi, Tak-Ho,Reid, David H.,Nicol, Robin H.,Rhodes, Jane B.
, p. 1753 - 1760 (2007/10/02)
Several 4-alkyl-5-alkylimino-Δ2-1,2,4-thiadiazolines have been synthesized from 1,2,4-thiadiazoles, namely 3,4-dimethyl-5-methylimino-Δ2-1,2,4-thiadiazoline 9, 3-methyl-6,7-dihydro-5H-1,2,4-thiadiazolopyrimidine 24, 6,7-dihydro-5H-1,2,4-thiadiazolopyrimidine 26, and 3-methyl-5,10-dihydrobenzo-1,2,4-thiadiazolodiazepine 34.Cycloaddition reactions of compounds 9, 24, 26 and 34 were carried out in order to synthesize 1H,6H-3aλ4-thia-1,3,4,6-tetraazapentalenes 6, whose system is a hitherto unknown variation of the 1,6,6aλ4-triheterapentalene structure.Compound 9 failed to react with nitriles and decomposed under forcing conditions.Compounds 24, 26 and 34 underwent cycloaddition with nitriles, with elimination of acetonitrile from 24 and 34 and of hydrogen cyanide from 26, and incorporation of the nitrile into the product 4-alkyl-5-alkylimino-Δ2-1,2,4-thadiazoline. 1H,6H-3aλ4-Thia-1,3,4,6-tetraazapentalenes 6 were not isolated or detected spectroscopically but it is proposed that they are intermediates in the cycloaddition of 4-alkyl-5-alkylimino-Δ2-1,2,4-thiadiazolines with nitriles.The heterocyclic system 34 is a new one.
Reaktionen koordinierter Liganden V. Pentacarbonylhalogenaminophosphinkomplexe (CO)5MPRXNR'2 durch Umsetzung von (CO)5MPR(NR'2)2 mit Halogenwasserstoff
Diemert, K.,Kuchen, W.,Lorenzen, D.
, p. 17 - 32 (2007/10/02)
Aminophosphines RP(NR'2)2 (R = Ph, cyclo-Hex, (-)-Men, t-Bu; R' = Me, Et) as ligands L in complexes (CO)5ML (M = Cr, Mo, W) have been found to react with HX (X = Cl, Br) mainly under substitution of only one of the two dialkylamino groups by halogen.Under similar conditions the free phosphines are converted into the dihalogenphosphines.The halogenamino complexes (CO)5MPRXNR'2 are readily accessible by this reaction, the mechanism of which is discussed.The preparation of several new compounds RP(NR'2)2 is reported.
EFFECT OF THE STRUCTURE OF AMINES ON RATE AND MECHANISM OF THEIR REACTIONS WITH 2-(β,β-DIBROMOVINYL)-5-NITROFURAN IN ACETONITRILE
Kravchenko, V. V.,Kotenko, A. A.,Popov, A. F.,Kostenko, L. I.,Vegh, D.,Kovac, J.
, p. 2140 - 2143 (2007/10/02)
The kinetics of the reaction of 2-(β,β-dibromovinyl)-5-nitrofuran with alkylamines of various types (primary, secondary, and tertiary) in acetonitrile at 55 deg C were studied.It was shown that enamines are formed quantitatively in the case of the reactions with secondary amines.At the same time the products from the reactions with primary amines are the corresponding amidines.Here the monosubstitution product is formed at the first stage, as in the case of the reactions with secondary amines, and rearranges to the imidoyl halide with subsequent substitution of the halogen atom at the imidoyl carbon atom.A quantitative assessment is made of the effect of the structure of the enamine on the rate of the processes.
KINETICS AND MECHANISM OF REACTION OF AMINES WITH β-BROMOPROPIOPHENONE
Popov, A. F.,Piskunova, Z.,Matvienko, V. N.
, p. 1299 - 1302 (2007/10/02)
The reaction of β-bromopropiophenone with different amines in acetonitrile at 25 deg C was studied.It was found that in the case of primary and secondary amines, the end products of the reaction are β-aminopropiophenones, which form via the intermediate phenyl vinyl ketone.In the case of tertiary amines, the reaction ends at the stage of the formation of phenyl vinyl ketone.The reactivity of the amines in the formation of phenyl vinyl ketone is preferentially determined by their basicity.
