Synthesis, Characterization, and Physicochemical Studies Of Orientation‐Controlled Multi‐Arm PEG Zn(II)/Mg(II) (Aza)Phthalocyanines

Abstract

Tuning the amphiphilicity of (aza)phthalocyanine hydrophobic cores by introducing multiple polyethylene glycol (PEG) moieties with controlled orientations of their (non)peripheral positions is an innovative approach to fabricating water-soluble macrocyclic materials. Although many water-soluble PEGylated macrocycles have been produced in this way, the ability to generate substances with PEG tails oriented outward from the macrocyclic plane in order to obtain non-aggregated, water soluble forms remains a challenge. In this study, we resolved this issue by developing a methods for the synthesis of four new dual directional PEG containing Zn(II)/Mg(II) amphiphiles (ZnPcÀ PEG, MgPcÀ PEG, ZnAzaPcÀ PEG and MgAzaPcÀ PEG). In addition, the non-aggregating behaviour, and photophysical and photochemical properties of these PEG-complexes were elucidated.

Covalently linked pyrene antennas for optically dense yet aggregation-resistant light-harvesting systems

“…26,27 Often this approach puts limitations on the types and concentrations of light-absorbers to be used though, as aggregation of these can lead to unwanted non-radiative decay that competes with emission and/or FRET. [28][29][30] For example, small aromatic hydrocarbons such as perylene or pyrene (Py) possess strong absorption bands, making them appealing for use as molecular absorbers. However, their flat and electron-rich structure also makes them highly susceptible to aggregation, with many studies reporting chemical modifications or other strategies designed to prevent this.…”