Room-Temperature Metal-Free Multicomponent Polymerizations of Elemental Selenium toward Stable Alicyclic Poly(oxaselenolane)s with High Refractive Index

Abstract

Selenium-containing polymers are a group of fascinating functional polymers with unique structures, properties, and applications, which have been developed recently but only with limited examples. The challenges of developing selenium-containing polymers with structural and functional diversity include the lack of economic and safe monomers, lack of efficient and convenient synthetic approaches, and poor stability of selenium-involving covalent bonds. In this work, room-temperature metal-free multicomponent polymerizations (MCPs) of elemental selenium, diisocyanides, and dipropargyl alcohols were developed, and polymers with a selenium-containing aliphatic heterocycle, 1,3-oxaselenolane, were synthesized through these MCPs directly from elemental selenium. The alicyclic poly­(oxaselenolane)­s enjoyed high yields (up to 93%), high molecular weights (up to 15 600 g/mol), high thermal and chemical stability, good solubility and processability. With the structural design of the poly­(oxaselenolane)­s and their high selenium contents of up to 33.7 wt %, the refractive indices of their spin-coated thin films could reach 1.8026 at 633 nm and maintain 1.7770 at 1700 nm. It is anticipated that these efficient, convenient, mild, and economic multicomponent polymerizations of elemental selenium can promote the selenium-related polymer chemistry and accelerate the exploration of diversified selenium-containing functional polymer materials.

One-Pot Multicomponent Polymerization, Metal-, and Non-Metal-Catalyzed Synthesis of Organoselenium Compounds

“…It is worth noting that poly(oxaselenolane)s were obtained in high yields (up to 93%), high Se contents (up to 33.7 wt %), high molecular weights (up to 15 600 g/mol), and high thermal and chemical stability as well as excellent light refractivity, good solubility, and processability. Furthermore, the polymerization reaction encompassed a broad scope of the diisocyanides (e.g., benzyl and aromatic) as well as various dipropargyl alcohols ( Scheme 44 ) [ 92 ].…”

Synthesis of colorless and high-refractive-index sulfoxide-containing polymers by the oxidation of poly(phenylene sulfide) derivatives

“…High refractive index polymers (HRIPs) have attracted much attention in the field of various optical devices, owing to their flexibility, light weight, and high light extraction efficiency. 1,2 The refractive index (RI, n) of a polymer is quantitatively determined using the Lorentz-Lorenz equation, which explains that atomic groups with high molar refraction ([R]) and low molecular volume (V) afford HRIPs; sulfur, [3][4][5] aromatics, 6,7 and heavy chalcogenides [8][9][10] are frequently introduced in the repeating units of HRIPs. Our group found that poly(phenylene sulfide) (PPS), regarded as one of the super engineering plastics with high crystallinity and thermal stability, became completely amorphous once it was derivatized with alkyl or alkoxyl side groups.…”

Diselenide–yne chemistry for selenium-containing linear polymer modification

“…Research peers worldwide have developed many novel synthetic methods for selenium-containing polymers, which have provided various building blocks for further application. At present, there are three main synthetic methods for selenium-containing polymers: step growth polymerization, [27][28][29] radical polymerization [30][31][32] and ringopening polymerization. [33][34][35] Different methods lead to polymers with various structures and functions.…”