Framing Function: Metallophthalocyanine-Based Metal–Organic Frameworks as Multifunctional Materials for Electrified Devices

Metallophthalocyanine-based metal-organic frameworks (MPc-based MOFs) have recently emerged as a class of two-dimensional (2D) materials with unique tunability for control over both structural properties and growing applications. MPc-based MOFs possess a unique set of structural characteristics due to the combination of a two-dimensional, sheet-like, porous structure and a modular, bimetallic molecularly precise chemical composition that result in emergent properties, such as electrical conductivity, modular surface chemistry, and tunable stacking properties. This combination of physical, chemical, and structural modularity has led to the promising demonstrations of MPc-based MOFs within a wide range of applications, including chemical sensing, catalysis, energy storage, and magnetoresistivity. While recent research regarding structure-property relationships of these materials has significantly advanced this field, the exploration of this class of 2D conductive MOFs has been limited by factors including the synthetic accessibility of both the functionalized MPc monomer and the crystalline framework materials, as well as the lack of structural clarity due to limitations in producing sufficiently large ordered crystals suitable for single crystal X-ray diffraction. Systematic investigation of structure-property relationships, enabled by careful control over synthetic parameters and device integration techniques, are essential for advancing the fundamental understanding and capitalizing on the applied potential of this class of materials. This Account summarizes the development of MPc-based MOFs as a privileged class within the realm of conductive 2D framework materials. Furthermore, this Account highlights key contributions from our group, with a particular focus on how chemical modulation within MPc building blocks dictates the resulting MOF structures and their functional performance. Capitalizing on the beneficial properties of the MPc building blocks, the structural modularity of these materials provides unique access to systematic investigations of structure-property relationships. Structure-property related insights make it possible to elucidate the role of the metal within the MPc core, the bridging metal, and the heteroatomic linker on the functional performance of these materials in the context of electronically transduced chemical sensing and electrocatalysis. The multifaceted utility of this class of materials is also highlighted in both energy storage applications and magnetoresistive devices. Through a combination of iterative synthetic efforts, characterization studies, and systematic investigations into electrical devices incorporating MPc-based MOFs, this Account demonstrates that these materials are prime candidates for use in electronically transduced devices where molecular-level control can be leveraged to maximize device performance metrics. Taken together, these achievements establish MPc-based MOFs as a promising class of materials with high potential within the field of functional nanoscience.