Modular Core‐Substituted Naphthalenediimide‐Based Metal–Organic Frameworks for Red‐Light‐Driven Photocatalysis

Abstract

ABSTRACT Red‐light‐driven photocatalytic reactions present a superior alternative for overcoming inherent limitations of conventional ultraviolet (UV) and blue‐light photocatalysis, including shallow penetration depth, photodamage of light‐sensitive compounds, and limited reaction selectivity. Nevertheless, molecular engineering strategies for achieving efficient red‐light heterogeneous photocatalysts remain scarce and pose significant challenges. Herein, this work designed and synthesized two novel isostructural metal–organic frameworks (MOFs, denoted as NHEt‐cNDI‐Cu 3 and SEt‐cNDI‐Cu 3 ) based on core‐substituted naphthalenediimide (cNDI) derived dyes. The two MOFs exhibited comparative high surface area and decent water/chemical stability. Intriguingly, their broad and intense light absorption, which is intrinsically inherited from their constituent cNDI ligands, bestowed them with great promise in long‐wavelength light photocatalysis. Especially, NHEt‐cNDI‐Cu 3 was found to be quite prominent in photocatalyzed sulfide oxidations and oxidative coupling of benzylamine under red‐light irradiation. In contrast, the performance of its analogue, SEt‐cNDI‐Cu 3, was five times lower, although their photocatalytic activity was very close under blue‐light excitation. The mechanistic study further elucidated that the LUMO of cNDI‐based MOFs governed the photocatalytic reactivity, which furnished a new platform for molecular engineering design of long‐wavelength photocatalysts and subsequently boosted sustainable chemistry.