Molecular Engineering of Multifunctional Metallophthalocyanine-Containing Framework Materials

The recent development of metallophthalocyanine (MPc)-based frameworks has opened the door to a new class of promising multifunctional materials with emergent electrical, magnetic, optical, and electrochemical properties. This perspective article outlines the process of molecular engineering—which uses the strategic selection and combination of molecular components to guide the assembly of materials and achieve target function—to demonstrate how the choice of MPc-based molecular components combined with the toolkit of reticular chemistry leads to the emergence of structure–property relationships in this class of materials. The role of complexity and emergence as core principles of molecular engineering of functional materials is discussed. Subsequent illustration of the molecular design criteria that stem from the unique optical, electrical, magnetic, and electrochemical features of MPc monomers sets the stage for achieving emergent function on the basis of the underlying properties of the constituent molecular building blocks. The review of strategies available for the controlled assembly of MPc monomers employing the principles of self-assembly and reticular chemistry serves as a guide for the attainment of enhanced control over relative position, orientation, and aggregation of MPc building blocks, while creating opportunities to discover new emergent properties. The central focus on the advances in MPc-based framework materials shows how the electronic, photophysical, magnetic, and electrochemical properties in these materials emerge from molecular design principles that build on the initial properties embedded in MPc-based building blocks. Concluding remarks summarize accomplishments and pave the way for future directions.