Structures and short contacts of F⋯O(nitro) and H⋯O(nitro) in 2,2-di(4-nitrophenyl)hexafluoropropane and 2,2-di(4-nitrophenyl)propane
摘要:
2,2-Di(4-nitrophenyl)hexafluoropropane (1) and 2,2-di(4-nitrophenyl)propane (2) were synthesized and their crystal structures were determined. The crystals of both diarylpropanes have helical conformations with unsymmetrical ring-twist angles, phi(A) = 46.7, phi(B) = 33.5degrees for 1, and phi(A) = 64.9, phi(B) = 31.8degrees, for 2. In contrast, density functional theory calculations indicate symmetrical, helical C-2 states for both 1 (phi(A) = phi(AB) = 43.1degrees) and 2 (phi(A) = phi(B) = 51.5degrees). Intermolecular pi-pi-stacks along the a-axis of the crystals are composed of a pair of nitrophenyl rings oriented in opposite directions. Short contacts of O(nitro)F-... and O(nitro)H-...(Me) within the sum of van der Waals radii were also found in 1 and 2, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.
A regioselective nitration process for diphenyl compounds which can be carried out at about ambient temperature in which each ring of the diphenyl compound is selectively nitrated in the para position to form the corresponding di(4-nitrophenyl) compound. Such compounds as diphenyl carbonate, 2,2-diphenylpropane, 2,2-diphenylhexafluoropropane, diphenyl sulfide, diphenyl ketone, diphenyl sulfone, and the like can be converted to an isomeric mixture containing an enhanced amount of the corresponding di(4-nitrophenyl) compound, which mixture may be reduced or purified and reduced to the di(4-aminophenyl) analogues for use in the manufacture of polyamides, polyimides, and polyamide-imides.
Polurethaneaureas prepared with 2,2-bis(4-isocyanatophenyl)propane or 1,4-bis(4-isocyanato-alpha,alpha-dimethylbenzyl)benzene, and spandex spun from such polyurethaneureas, are provided.
Die Erfindung betrifft neue hochmolekulare Arylensulfidpolymere mit gegebenenfalls zusätzlich verbesserter Beständigkeit gegen UV-Strahlung, hergestellt durch Aufschmelzen von Arylensulfidpolymeren, vorzugsweise PPS, mit Polynitroverbindungen, bzw. mit Mononitroverbindungen, die mindestens einen weiteren zur Reaktion mit dem Arylensulfidpolymeren befähigten Substituenten tragen.
Verfahren zur Herstellung von 2,2-Bis-(aminophenyl)-propan
申请人:BAYER AG
公开号:EP0481316A1
公开(公告)日:1992-04-22
2,2-Bis-(aminophenyl)-propan mit einem Anteil des 4,4'-Isomeren von mindestens 70 % kann hergestellt werden, indem man 2,2-Diphenyl-propan zu 2,2-Bis-(nitrophenyl)-propan nitriert und dieses in einem nachfolgenden Schritt zu 2,2-Bis-(aminophenyl)-propan reduziert.
Process for the preparation of trisubstituted ureas by reductive carbonylation
申请人:ARCO Chemical Technology, L.P.
公开号:EP0507616A1
公开(公告)日:1992-10-07
Preparing a trisubstituted urea by reacting a nitroarene with carbon monoxide and a secondary amine in the presence of a Group VIII transition metal catalyst and optionally one or more promoters selected from primary amines, halide ion-containing compounds, chelating phosphorus and nitrogen compounds, water, hydrogen, compounds containing at least one active hydrogen atom and redox metals.