21990-63-6Relevant academic research and scientific papers
Direct Synthesis of Dibenzophospholes from Biaryls by Double C-P Bond Formation via Phosphenium Dication Equivalents
Nishimura, Kazutoshi,Hirano, Koji,Miura, Masahiro
supporting information, p. 3185 - 3189 (2020/04/21)
We have developed a new strategy for the generation of phosphenium dication equivalents from readily available phosphinic acids and Tf2O. The in situ-generated dication equivalents can be readily coupled with simple (hetero)biaryls to form the corresponding dibenzophospholes directly. This protocol can also be applied to the concise synthesis of six- A nd seven-membered phosphacycles as well as the largely ?-extended heteroacene derivatives, which are of great interest in the field of organic functional materials.
Phosphorus-containing copolyesters: The effect of ionic group and its analogous phosphorus heterocycles on their flame-retardant and anti-dripping performances
Zhang, Yi,Ni, Yan-Peng,He, Ming-Xin,Wang, Xiu-Li,Chen, Li,Wang, Yu-Zhong
supporting information, p. 50 - 61 (2015/03/05)
A series of copolyesters containing ionic groups (PETIs-K) were synthesized by melt co-polycondensation using terephthalic acid, ethylene glycol, and potassium salt of bishydroxyethyl ester of 10-hydroxy-10-oxo-10H-phenoxaphosphine-2,8-dicarboxylic acid (DHPPO-K) as monomers. The copolyesters only with analogous phosphorus-containing heterocycles (PETPs) were also synthesized and used as a control. The dynamic rheological behaviors confirmed that the complex viscosity of PETIs-K increased with increasing temperature due to the existence of ionic aggregates, which restricted melt dripping, while PETPs had flow behaviors similar to PET: the complex viscosity decreased with increasing temperature. The ionic groups induced the decomposition of the polymer backbone to form a more stable residue at high temperatures, which made PETIs-K exhibit good flame retardancy even with low phosphorus contents. Cone test showed the peak heat release rate and total smoke production of PETP5 decreased to 34% and 58% of pure PET. Compared with PETP5, these values for PETI5-K were reduced by 31% and 50%, respectively. EDX and ICP-AES results demonstrated that 92% of phosphorus for PETI10-K remained in char residues; however, this value for PETP10 was only 45%. Combined with results of XPS, Raman spectroscopy and Py-GC/MS, it can be proved that the ionization of phosphorus took main effects in condensed phase via promoting carbonization to form stable graphitic char, which avoided the decrease of carbonization due to the competitive effects of phosphorus in gas phase.
