Synthesis, Characterization, and Ring-Opening Polymerization of the Cyclic Oligomers of Poly(Oxy-1,3-phenylenecarbonyl-1,4-phenylene)

Synthesis and characterization of a cyclic 9,9-bis(4-hydroxyphenyl)fluorine (phenylene phosphonate) oligomer and its flame retardancy application

A novel solid flame retardant cyclic 9,9-bis(4-hydroxyphenyl)fluorine (phenylene phosphonate) (CPFP) oligomer was synthesized in high yields by the reaction of phenylphosphonic dichloride with 9,9-bis(4-hydroxyphenyl)fluorine under pseudo-high-dilution conditions.

5,7,13,15-Tetra-oxo-2,2,10,10-tetra-kis-(trifluoro-meth-yl)-4,8,12,16-tetra-oxa-1(1,4),3(1,4),6(1,2),9(1,4),11(1,4),14(1,2)-hexa-benzenahexa-deca-phane tetra-hydro-furan monosolvate

The title compound, C₄₆H₂₄F₁₂O₈·C₄H₈O, consists of a cyclic aryl ester dimer and a tetra­hydro­furan mol­ecule. In the structure of the cyclic dimer, one carbonyl group stretches above the cavity and the other below.

Selective synthesis of novel cyclic phenylazomethine trimers

Novel cyclic phenylazomethine trimers (CPAs) were synthesized in a one-step dehydration of the 4-aminobenzophenone derivatives in the presence of TiCl(4) or p-toluenesulfonic acid (PTS). The CPAs were isolated in over 90% yield under nondilute conditions. When using TiCl(4) as the dehydration agent, the induction of bulky substituents at the alpha-position of the substrate enhanced the yields of the CPAs. On the other hand, PTS served as an effective catalyst for the synthesis of the phenyl-substituted CPA. This different reactivity between TiCl(4) and PTS depends on the dehydration mechanism being dominated by a kinetic process or thermodynamic one. The obtained CPAs were confirmed by NMR, UV-vis spectra, and MM2 calculation to have only a Z conformation and a nonconjugated structure compared to the linear oligophenylazomethines (OPAs) and the aniline-capped OPAs (OPA's).