Cage‐Like Sodalite‐Type Porous Organic Salts Enabling Luminescent Molecule's Incorporation and Room‐temperature Phosphorescence Induction in Air

Abstract

Expression of room‐temperature phosphorescence (RTP) in organic materials requires complicated molecular design and specific intermolecular interactions, and therefore types of RTP materials are restricted. This work presents cage‐like sodalite‐type porous organic salts (s‐POSs) as host materials for luminescent molecules to induce RTP, using tetrasulfonic acid with an adamantane core and triphenylmethylamines that are modified with substituents in the para‐positions of benzene rings (TPMA‐X). By adding a representative luminescent molecule (pyrene) to a reaction solution during construction of s‐POSs, the molecule is incorporated in a facile manner. s‐POSs with a heavy halogen atom (X: Iodine) on the pore surface give heavy atom effects, suppression of thermal vibration, and protection from oxygen, for the incorporated molecule, which induce its RTP even in air. This strategy can be applied to various luminescent molecules, which may lead to the achievement of RTP of various colors.

Crystalline porous organic salts

“…60 Subsequently, utilizing the principles of reticular chemistry, it is possible to assemble tetrahedrally stable supramolecular clusters into CPOSs with dia topology using the rational design of organic acids. 31–33 Furthermore, the introduction of halogen atoms onto TPMA also led to the formation of alternative topological structures in CPOSs, such as sod topology. 33 Hence, reticular chemistry can predict the topology of CPOSs to some extent.…”

“…31–33 Furthermore, the introduction of halogen atoms onto TPMA also led to the formation of alternative topological structures in CPOSs, such as sod topology. 33 Hence, reticular chemistry can predict the topology of CPOSs to some extent. However, due to the flexible and non-directional nature of ionic bonds, accurately predicting their crystal structures, similar to the case of COFs, remains highly challenging.…”

“…13(a)), boasting pores larger than 20 Å and narrow windows with a maximum width of less than 8 Å. 33 The unique cage-like structure allows organic molecules to be confined within the pores, rendering CPOSs highly desirable as host frameworks for luminescent molecules. Notably, AdPS/TPMA-I with permanent porosity, possessing iodine exposed on the pore surface (Fig.…”

“…23–25 In contrast, ionic bonds facilitate the formation of porous organic materials termed CPOSs. 26–38 Depending on their long-range structural order, these materials can further be categorized as amorphous or crystalline porous organic materials.…”

Incorporation of Coronene into Cage‐like Porous Organic Salts and Induction of its Room‐Temperature Phosphorescence in Air

“…We previously reported that various sulfonic acids and bulky triphenylmethylamine ( TPMA ) constructed porous organic salts ( POS s), [19] one of the crystalline porous materials, via charge‐assisted hydrogen bonding [20] . Furthermore, as Figure 1 shows, tetrasulfonic acid with bulky adamantane core (4,4’,4’’,4’’’‐[adamantane‐1,3,5,7‐tetrayl]tetrabenzenesulfonic acid; AdPS ) and TPMA−X ( X = I, Br, Cl ), where heavy atoms (halogen) that promote intersystem crossing were introduced in the para ‐position of benzene rings of TPMA , constructed cage‐like sodalite‐type porous organic salts ( s ‐POS s) with heavy atoms exposed on the pore surface (Figure 1 right portion) [21] . The s ‐POS s showed no adsorption of oxygen (Figure S1); therefore, incorporating a luminescent molecule (pyrene) induced the RTP in air, by suppressing non‐radiative deactivation, protection from oxygen, and the external heavy‐atom effect.…”