Isophthalate-Based Room Temperature Phosphorescence: From Small Molecule to Side-Chain Jacketed Liquid Crystalline Polymer

Abstract

Isophthalate with the simple chemical structure is identified as an effective phosphor for room temperature phosphorescent (RTP) materials. With −Br, −CH 3 , and −CHCH 2 at the 5-position of the benzene ring of didecyl isophthalate, the three crystalline small molecules of DDIP-Br, DDIP-CH 3 , and DDIP-CHCH 2 demonstrate ultralong RTP with lifetime of 236, 650, and 184 ms, respectively, although no specific interactions are recognized in the crystals. Radical polymerization of DDIP-CHCH 2 readily results in Poly-1, which is the first RTP liquid crystalline polymer.Direct attachment of isophthalate phosphor to every repeating unit of polyethylene backbone through a single carbon−carbon bond leads to a significant side-chain jacketing effect, greatly reducing the motion of phosphor moieties. Poly-1 renders a columnar LC phase constructed by parallel packing of the supramolecular column that is composed of two Poly-1 chains. In the column, the isophthalate phosphor is confined in between the core of polymer backbones and the shell of decyl tails, and thus the nonradiative process is further suppressed. The materials design of Poly-1 can be widely applied for developing new RTP polymers.

Phase Behavior of Phasmidic Mesogen-Jacketed Liquid Crystalline Polymers Displaying Chain Bundling

“…Multichain column models have been suggested for some other side-chain polymers of which the side chains are dendron-like, , hemiphasmid-like, − fork-like, , or linear. − It is generally acknowledged that the backbone bundle lies in the column center as illustrated in Scheme a. Considering the special supramolecular organization of phasmidic molecules, the model shown in Scheme b may be more reasonable for PNB-12.…”

Recent Advances of Polymer‐Based Pure Organic Room Temperature Phosphorescent Materials

“…In 2019, Chen and co‐workers first achieved RTP emission from a liquid crystalline polymer system without strong intermolecular interactions or covalent cross‐links through designing and synthesizing a series of isophthalate derivatives based RTP materials with only weak intermolecular interactions, including small molecules, compounds 14–16, and polymer P6 (Schemes 1c and 2). [ 66 ] Single‐crystal analyses of those small molecules revealed that only weak Van der Waals interactions existed between the molecules ( Figure a–c). The resultant system offered a new strategy to construct applicable RTP materials in the liquid crystalline state, in which the polymer structure and the side‐chain jacketing effect provided enough restriction for suppressing the phosphors’ movement to a great extent, thus emitting green phosphorescence after cyan fluorescence (Figure 8d).…”

Unveiling the crucial contributions of electrostatic and dispersion interactions to the ultralong room-temperature phosphorescence of H-bond crosslinked poly(vinyl alcohol) films

“…[22][23][24] Apart from noncovalently doping systems, covalently embedding organic phosphors into polymer matrices is also an efficient strategy to achieve organic amorphous RTP materials. [25][26][27][28][29][30] For instance, Fraser and co-workers firstly reported a single-component polymer exhibiting fluorescence/phosphorescence dual emissions by covalently linking boron difluoride dibenzoylmethane into the terminal of poly(lactic acid) (PLA). 1a Also, Ma et al proposed a universal strategy to achieve efficient RTP through radical binary copolymerization of acrylamide and various organic phosphors.…”