17.9.24 Phthalocyanines and Related Compounds (Update 2017)

Abstract

This review updates the original Science of Synthesis chapter (Section 17.9) on phthalocyanines and various ring-fused, ring-contracted, and ring-expanded analogues. It adds some recently published methods, examples, and variations on the synthesis of unsubstituted phthalocyanines and metal phthalocyanines, as well as identically and nonidentically substituted phthalocyanine derivatives. Besides peripheral substitution, axial functionalization is also discussed, but attention is focused only on those methods that represent appreciable progress for a particular type of metal coordination and axial functionalization, provide phthalocyanines with specific features such as chirality, or allow the functionalization of phthalocyanines with entities that are difficult to introduce at the peripheral sites. This account also includes sections on new types of phthalocyanine derivatives and analogues that were not covered in the original chapter, as well as the progress made in the synthesis of some of these families in the decade since 2003.

Synthesis and reactivity of the apically functionalized (pseudo)macrobicyclic iron(ii) tris-dioximates and their hybrid phthalocyaninatoclathrochelate derivatives comprising reactive and vector terminal groups

“…6 During recent decades, the chemistry of phthalocyanines has shown uninterrupted growth. 7 In addition to the aforementioned traditional practical applications, Pcs and their polymeric and hybrid derivatives, as well as their macroheterocyclic analogs, have been intensively and successfully used as homo- and heterogeneous catalysts, 8 photosensitisers for photodynamic tumor therapy in the red and NIR spectral ranges, and antibacterial composites, 9 fluorescent probes for bioimaging, 10 semiconductors, 11 functional polymers and liquid crystals, 12 light-harvesting modules for dye-sensitized solar cells and organic photovoltaics, 13 molecular switches, 14 single-ion molecular magnets, 15 sensors, 16 and prospective organo-inorganic materials for non-linear optics 16,17 as well. So, the molecular design of their hybrid derivatives, binuclear phthalocyaninatoclathrochelates, 18 the molecules of which can be functionalized with terminal reactive group(s), allows a wide range of polytopic cage complexes to be obtained for further bioscreening and/or optical testing.…”

A Green-to-Near-Infrared Photoswitch Based on a Blended Subporphyrazine–Dithienylethene System

“…SubPz–DTE 1 consists of a A 2 B type SubPz, in which the B unit is endowed with two 2,5-dimethylthiophene rings that are directly connected to the macrocycle (Scheme ). A units and the axial position are substituted with alkyl substituents and a tert -butylphenoxy group, respectively, both providing solubility and stability to the system, without altering the absorption profile. ,, Hybrid 1 was assembled in 88% yield by a Liebeskind–Srogl coupling of bis-thioether-substituted SubPz 4 , with 2,5-dimethyl-3-boronic acid ( 5 ), following the previously reported methodology for peripheral functionalization of SubPzs (Scheme ).…”

“…Consequently, we anticipated a closed state in 1 with a deeply perturbed SubPz π-system, which would lead to red-shifted absorption and altered luminescent properties. SubPz−DTE 1 consists of a A 2 B type SubPz, 14 in which the B unit is endowed with two 2,5-dimethylthiophene rings that are directly connected to the macrocycle (Scheme 1). A units and the axial position are substituted with alkyl substituents and a tert-butylphenoxy group, respectively, both providing solubility and stability to the system, without altering the absorption profile.…”

“…7,8 SubPz intermediate 4 was prepared by crossover cyclotrimerization of dipropylmaleonitrile (2) and bis-p-nitrobenzylsulfanyl maleonitrile (3) (Scheme 2). This type of mixed cyclization is by far the most common procedure for preparing unsymmetric azaporphyrin derivatives, 14 although this work constitutes the first example within SubPzs. The reaction gave rise to a mixture of two SubPzs, namely, the symmetric hexapropyl-SubPz (A 3 ) and the unsymmetric (A 2 B) SubPz 4, which were separated by chromatography.…”