Perylenediimide-Based Hybrid Materials for the Iodoperfluoroalkylation of Alkenes and Oxidative Coupling of Amines: Bay-Substituent-Mediated Photocatalytic Activity

Abstract

Inorganic−organic donor−acceptor hybrid compounds are an emerging class of multifunctional crystalline materials with well-defined structures built from semiconductive inorganic and organic components. Perylenediimides (PDIs) are a prominent class of electron-deficient organic dyes, which can undergo consecutive photoinduced electron transfers to generate doublet excitedstate radical anions for photoredox-inert chemical bonds. Thus, this is an excellent organic component for building hybrid materials to study the structure−property relationships in organic synthesis. In this context, three molecular structure modified PDI-based hybrid materials, (Me 4 -PDI) 2 •SiW 12 O 40 (1), (Me 4 -Cl 4 -PDI) 2 • SiW 12 O 40 (2), and (Me 4 -Br 2 -PDI) 1.5 •HSiW 12 O 40 (3), were studied. By the introduction of different substituent groups at the bay positions, these three hybrid materials were successfully fabricated to investigate the impact of substituent groups on the photocatalytic activity. As expected, all PDI-based hybrid materials easily underwent consecutive photoexcitation to obtain their excited-state radical anions. However, experimental and theoretical analyses showed that these obtained excited-state radical anions displayed unusual bay-substituent-group-dependent photocatalytic conversion activities for the iodoperfluoroalkylation of alkenes and oxidative coupling of amines. Higher conversion yields were obtained for complexes 1 and 3 (bay-unsubstituted and Br-substituted PDI hybrid materials, respectively), and lower conversion was observed for complex 2 (Cl-substituted PDI hybrid material), which is attributed to the excited-state SOMO-1 energies of the PDI radical anions. The structure−property relationship established in this work provides insights for the further exploration of baysubstituted PDI hybrid materials in other small-molecule photocatalytic transformations.

Polyoxometalate‐dependent Photocatalytic Activity of Radical‐doped Perylenediimide‐based Hybrid Materials

“…Polyoxometalates (POMs), a class of anionic metal oxide clusters with oxygen-rich surfaces, are good photoactive electron reservoirs; they can potentially undergo photoinduced electron-or proton-transfer processes, which can be used to fabricate donor-acceptor hybrid materials with electron-deficient PDIs through unusual anion-π interactions. [44][45][46][47][48] Our and other groups have synthesized a series of photoactive hybrids based on POMs and functional organic ligands by taking advantage of noncovalent interactions, [49][50][51][52][53][54] but the application of these systems in promoting organic transformations has not yet been explored. Herein, we prepared a series of extremely rare radical-doped donor-acceptor hybrid materials, namely Cl (4), based on electron-deficient PDI and Keggin-type POM anions; they exhibited fast-responsive reversible photochromism and reactive organic radicals under ambient conditions, which resulted from the interactions of PDI radical anions and POMs (Figure 1).…”

Boosting Lithium Ion Storage of Copper Squarate Via Unsaturated Coordination Frameworks

“…It is essential to continuously develop new electrochemical energy storage systems with high efficiency and cheap cost in order to meet the demands of current equipment, which include better energy density and high-rate charge/discharge performance. − Therefore, rapid charge/discharge rates and high reversible capacity electrode materials are the subject of increasing research on lithium-ion batteries. − The traditional graphite anode (372 mA h g –1 ) based on the intercalation mechanism has difficulty meeting the requirements, − so it is necessary to explore other high-performance lithium-ion battery anode materials.…”