Synthesis of Blue-Luminescent Seven-Membered Phosphorus Heterocycles

Abstract

A facile synthetic procedure to prepare π-extended seven-membered phosphorus heterocycles, both symmetric and asymmetric, is reported. The prepared molecules present a persistent nonplanar framework and are soluble in a wide variety of solvents. The seven-membered phosphorus heterocycles can be electrochemically reduced and oxidized, and photoluminesce with a blue color.

Tailored Solvatochromic NIR Phosphorus-Chromophores via Selective P−N and P−C Chemistry in P-Heteropines

“…So far, research on five- and six-membered P-cycle-containing OCPs (Scheme ) has gained significant progress with respect to synthetic protocols, theoretical studies of chemical and electronic structures, and optoelectronic properties. ,− Although recent studies have demonstrated that the seven-membered P-OCPs (P-heteropines) are indeed promising candidates for optoelectronic applications, the research on P-heteropines is still in its infancy. − Similar to other P-cycles, the synthesis of P-heteropines generally involves highly reactive nucleophilic organometallic reagents, such as organolithium species or transition-metal catalysts. ,− The strong nucleophilic character of organometallic reagents can greatly limit the diversity of the chemical structures of P-heteropines, which will affect the exploration of new optoelectronic characteristics. Therefore, it is highly desirable to explore milder and more efficient synthetic protocols to construct P-OCPs with tunable optoelectronic properties.…”

Multilayer 3D Chiral Folding Polymers and Their Asymmetric Catalytic Assembly

“…The purpose of selecting thiadiazole synthon for this polymerization was based on the fact that it had been among the most frequently employed scaffolds in polymers and materials science, especially in the field of conductive polymers. The synthesis of the monomer of 8,8′-dibromo-1,1′-binaphthalene was very challenging since one of the critical steps involved the cross-coupling between 2-(8-bromonaphthalen-1-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane and 1-bromo-8-iodonaphthalene taking about two weeks in a poor yield [ 28 ]. Therefore, the first synthon pair was excluded temporarily.…”

Recent Advances in Luminescent Annulated Borepins, Silepins, and Phosphepins

“…Hissler's group 38 used an intramolecular Ni-mediated homocoupling of the phosphine oxides 62, which is similar to the method used to synthesize the borepin analogue DNB, 24 while Romero-Nieto and co-workers developed a late-stage ring-closure with a phosphorus linker from dibromide 63. 39 Crystal analysis revealed that phosphepins 64 have a highly twisted C-backbone. Similar to DNB, the incorporation of an ethylene bridge reduces H-H repulsion at the bay area and the distortion angle between two naphthyl-moieties, and leads to the redshift of the emission and absorption.…”