Efficient Synthesis of ABAB Functionalized Phthalocyanines

Abstract

ABAB-type Zn(II) phthalocyanines, crosswise-functionalized with two and four iodine atoms, respectively, have been efficiently prepared using statistical condensation procedures. Key to the selective preparation of the opposite ABAB isomers versus the adjacent AABB ones is the use of bulky 3,6-(3',5'-bis(trifluoromethyl)phenyl)phthalonitrile with hampered self-condensation capabilities.

Crosswise Phthalocyanines with Collinear Functionalization: New Paradigmatic Derivatives for Efficient Singlet Oxygen Photosensitization

“…On the other hand, appropriate functionalization of the Pcs with collinear lipophilic/hydrophilic substituents may lead to nanovesicles in water media, which can be envisioned as delivery systems for photodynamic and photothermal therapies (PDT) . In this regard, we have recently described the preparation of trans ‐A 2 B 2 Pcs containing: i) two crosswise isoindoles functionalized with bulky bis(trifluoromethyl)phenyl groups at the non‐peripheral positions, which provide solubility and hinder the aggregation between macrocycles; and ii) two crosswise isoindoles endowed with iodine atoms . Importantly, the presence of opposite iodine atoms has allowed us to prepare amino‐containing, ditopic Pc ligands able to self‐assemble into supramolecular cages by metal‐ligand coordination with iron(II) salts .…”

ABAB Phthalocyanines: Scaffolds for Building Unprecedented Donor-π-Acceptor Chromophores

“…3,6‐Bis‐(3,5‐bistrifluoromethylphenyl)phthalonitrile 2 a has proved very effective as a precursor for the preparation of ABAB Pcs (Scheme ) . Considering that octakis[α‐aryl]Pcs have been prepared under certain conditions, it seems that functionalization with bare phenyl rings at the α ‐positions of the phthalonitrile precursor is not enough to avoid the formation of Pcs with adjacent phenyl‐substituted isoindoles.…”

“…We have recently described the preparation of ABAB Pcs through the statistical condensation of bulky 3,6‐bis‐(3,5‐bistrifluoromethylphenyl)phthalonitrile, which is reluctant to give self‐condensation, owing to the presence of rigid/bulky groups at the o ‐positions of the CN moieties, and iodo‐containing phthalonitriles . In particular, ABAB Pc 1 a (Figure ) was successfully prepared in 16 % yield.…”

“…[a] E. Fazio We have recently described the preparation of ABAB Pcs through the statistical condensation of bulky 3,6-bis-(3,5-bistrifluoromethylphenyl)phthalonitrile, which is reluctant to give self-condensation, owing to the presence of rigid/bulkyg roups at the o-positions of the CN moieties, and iodo-containing phthalonitriles. [13] In particular, ABAB Pc 1a ( Figure 1) was successfully prepared in 16 %y ield. Importantly,t he presence of two iodine atoms in crosswisei soindoleso ffersaunique opportunity to synthesize face-to-face, push-pull ABAC Pcs by metal-catalyzed coupling reactions,a sw ell as to incorporate the Pc as ac entral block in multicomponent ensembles.…”

A Novel Covalently Linked Zn Phthalocyanine‐Zn Porphyrin Dyad for Dye‐sensitized Solar Cells

“…Torres et al. succeeded in preparing the unsymmetrically substituted ABAB‐type phthalocyanines, functionalized with two or four iodine atoms, using the same synthetic method 18. In this study, the ABAB‐type Pc, having two bromides at the opposite sites of the Pc ring, was synthesized by the statistical condensation reaction of 3,6‐diphenylphthalonitrile with 4‐bromophthalonitrile (Scheme ).…”