45467-78-5Relevant academic research and scientific papers
Bismaleamic acid, bismaleimide and cured product thereof
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, (2009/12/27)
A bismaleamic acid obtained by reacting a bifunctional phenylene ether oligomer diamine, obtained by introducing aromatic amino groups into both terminals of a specific bifunctional phenylene ether oligomer, with maleic anhydride, a bismaleimide obtained from the bismaleamic acid as a raw material, which bismaleimide has high heat resistance, low dielectric characteristics and excellent solvent solubility and exhibits only a small change in dielectric characteristics even in high humidity, a curable resin composition containing the above bismaleimide and a cured product obtained by curing the curable resin composition.
DYnamics of the Wolf Rearrangement of Six-Membered Ring o-Diazo Ketones by Laser Flash Photolysis
Tanigaki, Katsumi,Ebbesen, Thomas W.
, p. 4531 - 4536 (2007/10/02)
The Wolff rearrangement of six-membered ring o-diazo ketones, 1-oxo-2-diazo-1,2-dihydronaphthalene (DNQ) and its four 4- and 5-sulfonate analogues, 1-ox-2-diazo-1,2-dihydrobenzene (DBQ), and diazoMeldrum (DM), are studied in solution at room temperature by laser flash photolysis.A precursor to a ketene is observed in most cases.It is assigned to be an oxirene on the basis of reactivity, kinetic results and thermodynamic results.The Wolff rearrangement does not involve a concerted mechanism but a stepwise reaction for these types of diazo ketones.Thermodynamic analyses indicate that the activation barriers for the transformation of the oxiranes into ketenes are very low, typically 10-20 Kj/mol, in godd agreement with theoretical predictions in the literature.The observation of oxirene in solution in nanosecond time scales, and longer, is attributed to the low preexponential factors due to the negative entropy of solvatation.The important role of the solvent is further confirmed in the kinetic analysis of ketene formation in various water-methanol mixtures.
