3282-99-3Relevant articles and documents
Preparation method of aliphatic ring bridged aromatic diamine monomer
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Paragraph 0033-0056; 0065-0068, (2020/05/14)
The invention relates to a preparation method of an aliphatic ring bridged aromatic diamine monomer, and belongs to the technical field of preparation of diamine monomers for polyimide. According to the preparation method of the aliphatic ring bridged aromatic diamine monomer, cycloalkyl ketone and amine are used as raw materials, methylbenzene is used as an entrainer, a nucleophilic reaction is performed under the action of perfluorosulfonic acid resin/SiO2 solid acid catalyst, and then after-treatment is performed to obtain the aliphatic ring bridged aromatic diamine monomer. According to the method, the reaction temperature is reduced, the reaction time is shortened, the reaction yield is increased, the toxicity of after-treatment is reduced, the production cost is reduced, and the application range is wide.
Guanidine-guanidinium cooperation in bifunctional artificial phosphodiesterases based on diphenylmethane spacers; Gem -dialkyl effect on catalytic efficiency
Salvio, Riccardo,Mandolini, Luigi,Savelli, Claudia
, p. 7259 - 7263 (2013/08/23)
Diphenylmethane derivatives 1-3, decorated with two guanidine units, are effective catalysts of HPNP transesterification. Substitution of the methylene group of the parent diphenylmethane spacer with cyclohexylidene and adamantylidene moieties enhances catalytic efficency, with gem-dialkyl effect accelerations of 4.5 and 9.1, respectively. Activation parameters and DFT calculations of the rotational barriers around the C-Ar bonds indicate that a major contribution to the driving force for enhanced catalysis is entropic in nature.
Basic azo dyestuffs of the 3-cyano-2,4,6-triamino pyridine series
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, (2008/06/13)
The new basic azo dyestuffs of the formula STR1 wherein the symbols have the meaning given in the description, are suitable for dyeing synthetic and naturally occurring substrates which can be dyed with basic dyestuffs.