# A Redox‐Active Tetrathiafulvalene‐Based 3D Covalent Organic Framework with scu Topology for Controllable Charge Transport

## TL;DR

Researchers built a 3D material with a special structure that allows better control of electrical conductivity for potential use in energy storage and electronics.

## Contribution

A new 3D covalent organic framework (TU-48) with scu topology and redox-active TTF units is designed for tunable charge transport.

## Key findings

- TU-48 shows high structural order and porosity with redox-responsive electrochemical behavior.
- Electrical conductivity reaches 4.3 × 10−6 S cm−1 at 298 K and 1.8 × 10−4 S cm−1 at 393 K after iodine oxidation.
- The 3D framework enables multidimensional charge transport through TTF redox centers.

## Abstract

Unlike 2D frameworks where conductivity is largely confined to in‐plane transport, the scu topology offers 3D conduction pathways that enhance bulk charge mobility. When integrated with redox‐active species like tetrathiafulvalene (TTF), the scu architecture promotes electron transfer across the 3D network, enabling tunable conductivity. This article presents the construction of a 3‐periodic (4,8)‐c covalent organic framework (COF), TU‐48, adopting a twofold interpenetrated scu net, achieved through the integration of a tetratopic D
2h‐symmetric rectangular TTF structural motif and an octatopic D
2h‐symmetric quadrangular prism linker. TU‐48 exhibits high structural order, well‐defined porosity, and redox‐responsive electrochemical behavior. The high‐connectivity 3D COF configuration ensures effective access to TTF redox centers, enabling controlled iodine oxidation and resulting in electrical conductivities of 4.3 × 10−6 S cm−1 at 298 K and 1.8 × 10−4 S cm−1 at 393 K. By demonstrating how enhanced structural connectivity in TTF‐bridged 3D covalent lattices enables improved charge‐transport properties, this research fuels innovation in sustainable energy storage solutions and electronics.

This article presents the designed construction of a high‐connectivity, electrochemically tunable 3D covalent organic framework (TU‐48) with a scu‐c topology, incorporating tetrathiafulvalene‐based building blocks to enable multidimensional charge transport and achieve enhanced electrical conductivity through redox modulation and iodine doping.© 2025 WILEY‐VCH GmbH