Between porphyrins and phthalocyanines: 10,20-diaryl-5,15-tetrabenzodiazaporphyrins

Abstract

meso-Diaryltetrabenzo(opp)diazaporphyrins are made readily available via Curtius rearrangement of azidocarbonyl derivatives of meso-aryldibenzodipyrromethenes, readily generated with or without isolation from tert-butoxycarbonyl derivatives of the same system. The new tetrapyrrolic dyes are isostructural with 5,15-diaryltetrabenzoporphyrins and resemble both phthalocyanines and tetrabenzoporphyrins to afford an interesting new system for optical applications and material research.

Metal complexes of diaryltetrabenzodiazaporphyrins

“…The structure of Ar 2 TBDAP free ligand, is very close to that of 5,15‐diaryltetrabenzoporphyrin, in spite of markedly shorter C−N bond lengths at meso ‐nitrogen atoms, which is compensated by an adjustment of C−N‐C angles at meso ‐atoms, thus giving the structure of core with almost the same size of the internal N 4 rectangle in both types of ligands. Both structures share the same in‐plane distortion mode accounted for by steric repulsion between meso ‐aryl ring and two benzo‐rings, which results in a substantial widening of the fragment including the meso ‐aryl compensated by narrowing the fragments lacking meso ‐aryls .…”

“…In all four cases under discussion the arrangement of molecules in crystals minimizes their overlap, and stacking is limited to small fragments of molecules or altogether suppressed. Thus, the crystal packing of both zinc and copper complexes is quite close to the packing of the respective free ligand described elsewhere, with the main packing motif being 1D flat belts, arranged as a 2D‐ladder, with rather large interplanar distances (7.6 Å in free ligand 1 a; 7.1 Å in zinc complex; 6.9 Å in copper complex) with increasing degree of misalignment of the adjacent belts. Packing of Ni complex 2 e (see SI) superficially resembles a typical columnar herringbone pattern common for the phthalocyanine β‐phase, however, in this case the packing units are not single molecules, but the loose dimers (cf.…”

“…The only approach to diaryl‐derivatives known until recently was the template fusion reaction (the Kopranenkov‐Luk'yanetz method, for review see), a very simple and straightforward but often unselective and low‐yielding method, giving complex mixtures, from which both ( adj ) and ( opp ) isomers of Ar 2 TBDAP were isolated, but only the ( adj ) isomer was properly characterized, thus any data on the ( opp )‐Ar 2 TBDAP series has been missing until 2014, when an effective and selective synthesis of these hybrids by in situ dimerization of the products of Curtius rearrangement of bis ‐azidocarbonyl derivatives of meso ‐aryldibenzodipyrromethenes was discovered . The approach is based upon a general dihydroisoindole approach, which earlier opened access to major types of linearly annelated extended porphyrins and dipyrromethenes…”

Comparison of electronic effects of β-aryl substituents on optical and electrochemical properties of 5,15-diazaporphyrin π-systems

“…Because of these intrinsic properties, diazaporphyrins show intense and red-shifted Q-bands [3][4][5][6], and some derivatives have been investigated as potential sensitizers for use in photodynamic therapy [7], dye-sensitized solar cells [8], optical oxygen-sensing [9], and artificial photosynthesis [10]. However, guidelines for the molecular design of diazaporphyrin-based functional dyes that absorb both visible and near-infrared (NIR) light have not been yet established, because chemical functionalizations of the peripheral carbons with p-conjugative groups have…”

First examples of functionalisation of meso -aryl tetrabenzotriazaporphyrins (TBTAPs) through cross-coupling reactions

“…Our group has recently reported a new procedure for the controlled synthesis of TBTAP hybrids, 5 and a complementary approach to the transtetrabenzodiazaporphyrins (trans-TBDAPs) has separately been developed by Ceprakov and coworkers. 6 Alongside the new syntheses we have refined and improved the Grignard reagent initiated macrocyclisation approach, delivering the full range of hybrids in specific cases, 7 and most recently reporting the series of isomeric meso-(bromophenyl)TBTAPs. 8 The latter series were targeted as particularly useful intermediates for further functionalisation, and this paper describes the first successful extensions of this chemistry through cross-coupling reactions.…”