Molecular Engineering of Multifunctional Metallophthalocyanine-Containing Framework Materials

Abstract

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.

Self-Assembly of Chiral Cyclohexanohemicucurbit[n]urils with Bis(Zn Porphyrin): Size, Shape, and Time-Dependent Binding

“…2.1. Binding of Bis-ZnOEP with CycHC [6] and CycHC [8] The binding properties of bis-ZnOEP with cycHC[n]s were evaluated by 1 H-NMR and UV-vis titrations using only (R,R)-enantiomers of chiral macrocycles. A stepwise addition of cycHC [6] to the syn form of bis-ZnOEP in CD 2 Cl 2 shows the shielding of the meso-α protons of bis-ZnOEP (Figures 1 and 2A).…”

“…Binding of Bis-ZnOEP with CycHC [6] and CycHC [8] The binding properties of bis-ZnOEP with cycHC[n]s were evaluated by 1 H-NMR and UV-vis titrations using only (R,R)-enantiomers of chiral macrocycles. A stepwise addition of cycHC [6] to the syn form of bis-ZnOEP in CD 2 Cl 2 shows the shielding of the meso-α protons of bis-ZnOEP (Figures 1 and 2A). However, the addition of two equivalents of macrocycle was followed by the deshielding of the same signal in the presence of higher equivalency, which clearly indicates the presence of more than one structural transformation.…”

“…However, the addition of two equivalents of macrocycle was followed by the deshielding of the same signal in the presence of higher equivalency, which clearly indicates the presence of more than one structural transformation. The change in chemical shifts of signals is influenced by cycHC [6] binding and subsequent conformational switching of bis-ZnOEP. The conformational changes of bis-ZnOEP are generally evaluated by 1 H-NMR signals from the meso-β protons (Figures 1 and 2B).…”

“…Porphyrins and their derivatives are one of the cornerstones of life; they are responsible for storing and transporting oxygen [1], photosynthesis [2], and enzyme-catalyzed reactions [3,4]. Synthetic derivatives have a wide range of applications, e.g., catalysis, photodynamic therapy, and sensing [5][6][7][8][9]. The versatility of porphyrin application can be significantly improved by metal insertion and/or covalently linking two porphyrin rings into a bis-porphyrin structure.…”

“…Moreover, the complexation of bis-ZnOEP with relatively large multidentate molecules, such as cycHC[n]s, has not yet been studied. Thus, we present a binding study employing various spectroscopic techniques (UV-vis absorption, fluorescence (FS), CD, NMR), including variable temperature (VT) and time-dependent measurements to characterize the corresponding supramolecular complexes of bis-ZnOEP with enantiomerically pure cycHC [6] and cycHC [8], which have six and eight available urea binding sites, respectively.…”