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A complete series of solketal octasubstituted phthalocyanines have been synthesized, with peripheral (β) or non-peripheral (α) substitution pattern. Their ¹³C NMR and UV-vis properties are compared relatively to this substitution pattern or the nature of the central metal (Ni, Zn or H₂).

The goal of this study was to develop mixtures of peripherally halogenated boron subphthalocyanines (BsubPcs) to explore these macrocycles as mixed alloys for applications within the organic electronic space. These halogenated BsubPc mixtures were synthesized by reacting mixtures of commercially available phthalonitriles, namely 4,5-dichlorophthalonitrile (Cl₂-pn), 4,5-difluorophthalonitrile (F₂-pn), tetrachlorophthalonitrile (Cl₄-pn), and tetrafluorophthalonitrile (F₄-pn), with boron trichloride (BCl${}_3)$ to achieve mixed halogenation upon formation of the BsubPcs. More specifically, as named, Cl₂-pn + F₂-pn and Cl₄-pn + F₄-pn mixtures were used to form Cl-Cl${}_{2\mathrm{\text{n}}}$F${}_{2\mathrm{\text{m}}}$BsubPc and Cl-Cl${}_{4\mathrm{\text{n}}}$F${}_{4\mathrm{\text{m}}}$BsubPc, respectively. To establish a firm synthetic methodology, the reaction kinetics of forming the BsubPc mixtures from their respective phthalonitrile mixtures were compared to the kinetics of the standard procedures forming the individual BsubPcs, for example, Cl-Cl${}_{12}$BsubPc from Cl₄-pn. As we use BCl₃ to form the BsubPcs, the axial bond is in general chloride, but we observed again random fluoride axial exchange, and therefore moved to the second step to have complete axial fluorination. Crude mixed halogenated BsubPcs were sublimed at high purities to enable physical characterization, including a study of UV-Vis absorption spectra differentiation, and cyclic (CV) and differential pulse voltammograms (DPV) electrochemical differentiation. We also did density functional theory (DFT) calculations for points of physical properties comparison. The comparison points are together with fully peripherally chlorinated Cl${}_{\mathrm{\text{n}}}$BsubPcs and fluorinated F${}_{\mathrm{\text{n}}}$BsubPcs. Given the outcomes, we foresee in future studies the ability to tune different ratios of peripherally halogenated BsubPc mixtures via synthetic tools, to enable tuning of the HOMO LUMO energy levels, which could consequently tune their application and performance in organic electronics.

Boron subphthalocyanines (BsubPcs) are versatile molecules with advantageous properties for applications. The BsubPcs are synthesized by the cyclotrimerization of a phthalonitrile and are composed of three isoindole subunits bound by three aza-/imine-bridging nitrogens. There are a variety of BsubPc derivatives shown within the literature due to the differentiation of a phthalonitrile precursor. The differentiation of a phthalonitrile enables the peripheral functional groups. The BsubPcs can be derivatized in two steps: First step is the cyclotrimerization of a phthalonitrile in the presence of a strong Lewis Acid, typically a boron trihalide (BX3) and enables a remaining axial substituent that is a B-X${}_a$ bond; second step is optional, the B-X${}_a$ bond can react with a nucleophile and results in B-X${}_b$. If the starting phthalonitrile is asymmetric, it will result in a combination of isomers. For this study, our approach is to have bromine substituents and to study their physical properties to see if applicable to organic electronic applications; chlorine and fluorine have been in past studies as halogens are unique and variations may present useful tools as they are known for electronegativities. The general phthalonitrile with no substitutions is produced in industry from $o$-xylene. There are a variety of ways to synthesize other phthalonitriles with halogens. However, phthalonitriles can also be made by a method that has the most versatility with its substituents and can start with phthalic acid and go to phthalic anhydride to phthalimide to phthalamide and final to phthalonitrile; it is also possible to synthesize a phthalimide directly from phthalic acid, and this is part of this study as we were focusing on bromination, we also wanted to optimize the synthetic pathways to brominated phthalonitriles, and we took an engineering perspective and for this study, we wish to show you.