2782-47-0Relevant academic research and scientific papers
Synthesis and characterization of processable fluorinated aromatic poly(benzamide imide)s derived from cycloalkane substituted diamines, and their application in a computationally driven synthesis methodology
Pérez, German,Terraza, Claudio A.,Coll, Deysma,Ortiz, Pablo,Aguilar-Vega, Manuel,González, Darío M.,Tagle, Luis H.,Tundidor-Camba, Alain
, p. 121 - 129 (2019/01/10)
A new set of four fluorinated aromatic poly(benzamide imide)s was synthesized with the objective of preparing condensation polymers with good processability while maintaining high chemical resistance, thermal stability and good mechanical properties. Their synthesis was carried out using commercially available cycloalkane substituted diamines, 3,5-dinitrbenzoyl chloride and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) as starting materials. The research was focused on the influence of pendant groups and the testing of a computational methodology that could help to predict polymer properties based on their structure and available QSPR models. To this end, extensive tests were performed on these new poly(imide)s including, IR, NMR, X-ray diffraction, UV absorption, thermal stability, mechanical tests, gas permeation and solubility analyses. The results showed that the materials obtained present properties similar to many available commercial poly(imide)s. On the other hand, computational simulations demonstrated that the strategy followed could be useful in reducing the number of compounds to be synthesized and at the same time, maximize the success ratio of finding polymers with certain desired properties.
Significance of reagent addition sequence in the amidation of carboxylic acids mediated by PPh3 and I2
Wangngae, Sirilak,Duangkamol, Chuthamat,Pattarawarapan, Mookda,Phakhodee, Wong
, p. 25789 - 25793 (2015/10/20)
The outcome of the amidation reaction mediated by PPh3-I2 was found to be highly dependent on the addition sequence of the reagents. When triethylamine was subjected to a mixture containing PPh3, I2, and a carboxylic acid, acid anhydride was generated almost instantly, before treatment with an amine, presumably via an attack of carboxylate ion onto the acyl function of an acyloxyphosphonium salt. Nevertheless, when a PPh3-I2 mixture was treated with an amine, then a carboxylic acid, prior to adding the base, amide was rapidly formed in high yield with high chemoselectivity, most likely through an intermediate O,N-pentacoordinate phosphorane species as confirmed by ESI-MS technique.
