Cocrystals, Mixed Films, and Heterostructures Based on Metal Phthalocyanines: Structures, Intermolecular Interactions, and Functional Properties (Review)

Abstract

Metal phthalocyanines (MPcs) and their derivatives represent a unique class of organic semiconductors whose functional properties can be efficiently modulated at both molecular and supramolecular levels. In this review, we systematize the current advances in the synthesis of cocrystals, mixed films, and heterostructures based on MPcs, including their fluorinated analogues. We analyze the effects of composition, stoichiometry, and deposition conditions on the crystal structure, morphology, and functional characteristics of the obtained materials. Special attention is paid to the study of the role of noncovalent interactions, such as π–π stacking and hydrogen bonds, in the formation of ordered supramolecular ensembles. It is demonstrated that the effective combination of donor and acceptor components can result in ambipolar conductivity, decreased band gap, appearance of ferromagnetism at room temperature, and significantly enhanced charge carrier mobility. We discuss the strategy to control the molecular orientation and the degree of film order by means of molecular patterns, e.g., polyphenol, polythiophene, perylene derivatives.