Synthesis, Structures, and Near‐IR Absorption of Heterole‐Fused Earring Porphyrins

Abstract

Ar eaction sequence of regioselective peripheral bromination, Suzuki-Miyaura coupling with 2-borylated thiophene or pyrrole,and oxidative ring-closure with FeCl 3 allowed the synthesis of heterole-fused earring porphyrins 4Pd and 9Pd from the parent earring porphyrin 1.Differently pyrrole-fused porphyrins 5H and 6H and their Pd II complexes 5Pd and 6Pd were also synthesized.T he structures of 4Pd, 5H, 6Pd,a nd 8Pd have been revealed by X-rayanalysis to be slightly twisted owingtoconstraints imposed by heterole-fused structures. 5Pd exhibits an intensified band at 1505 nm, while 4Pd and 9Pd displays mall but remarkably red-shifted absorption bands reaching around 2200 nm.

Organoboron Complexes in Edge‐Sharing Macrocycles: The Triphyrin(2.1.1)–Tetraphyrin(1.1.1.1) Hybrid

“…The designed hybrids of triphyrin(2.1.1) and tetraphyrin(1.1.1.1) were obtained by catalytic reactions (Scheme ), taking 2 , a derivative predefined for Suzuki–Miyaura couplings that has also been applied for the formation of structures with multiple cavities, as a starting material. As we expected more complications for pyrrolic derivatives, we decided to start with furan analogues—the similar atomic radii of nitrogen and oxygen do not introduce extra steric hindrance, causing a repulsion as documented for tetraphyrins but also for triphyrins(2.1.1) …”

Multi‐Cation Coordination in Porphyrinoids

“…[2] Different structures of diboron porphyrinate and corrolatew ere synthesized using boron trihalides as reagents.T he reactions of BF 3 ·Et 2 Ow ith H 3 (Cor) and H 2 (Por) both produce complexes containing an F-B-O-B-F moiety,[ B 2 OF 2 (Cor)] À and [B 2 OF 2 (Por)] although with different stereochemistry.T he F-B-O-B-F group occupies one face of the corrolei nacisoid arrangement (51), in contrastt ot he corresponding porphyrin complexes B 2 OF 2 (Por), which adopt an asymmetric transoid geometry (50) where one boron sits out of plane of the N4 core and one boron sits within the plane.T he NMR spectra and X-ray crystal structureso f[ B 2 OF 2 (Cor)] À confirm that the two boron atoms prefer the dipyrromethene sites and DFT calculations proved that the cisoid dipyrromethene isomer is the most stable. [2,29] Interesting chemical properties were noticed for BF 2 - [22]and [20]smaragdyrins 54 and 55 respectively.B oth complexes are interchangeable via ar edox process (Scheme 13) switching their character from the Hückel aromatic to antiaromatic character according to the magnetic criterion. [18] At reatment of aromatic 54 and antiaromatic 55 with CuCl 2 in the presence of NaOAc gave hetero bimetal BF 2 - [20]smaragdyrin Cu II complex 56 in high yields, suggesting the facile oxidation of [22]smaragdyrin under these conditions.…”

“…[21] Furthere xploration of 'earring porphyrin" concept by the same research group resulted in obtaining molecules where tetraphyrina nd triphyrin motifs are additionally fused by heterole (thiphene, pyrrole) units (Figure 4). [22] The fusion caused significant changes in av alue of chemical shifts.Ac arbatriphyrynic b-pyrrolic protons in 40 a resonate at incredibly low-frequency region (d:3 .51, 3.36 ppm vs. 6.76-5.37 ppm in 38). Changesi nt etraphyrinic unit in comparison to the starting material 38 are smaller( d:7 .54, 7.38 ppm vs. 8.40, 8.34 ppm) and moderate in at hiophenem oiety (5.69, 4.22 ppm).…”

“…[2,29] Interesting chemical properties were noticed for BF 2 - [22]and [20]smaragdyrins 54 and 55 respectively.B oth complexes are interchangeable via ar edox process (Scheme 13) switching their character from the Hückel aromatic to antiaromatic character according to the magnetic criterion. [18] At reatment of aromatic 54 and antiaromatic 55 with CuCl 2 in the presence of NaOAc gave hetero bimetal BF 2 - [20]smaragdyrin Cu II complex 56 in high yields, suggesting the facile oxidation of [22]smaragdyrin under these conditions. The structure of 56 was confirmedb ys ingle-crystal X-ray analysis.…”

A Supramolecular Radical Dimer: High‐Efficiency NIR‐II Photothermal Conversion and Therapy

“…[19][20][21] However,organic PTT agent with NIR-II absorption is not easy to be achieved because of the narrow band gap. [22][23][24][25][26] Thecommon strategy is to construct alarge pconjugate with electron-donor and electron-acceptor groups, which need great skills and efforts to design and synthesize. Moreover,l imited solubility and strong aggregation in aqueous solution could be aproblem that limits their further applications.Through supramolecular approaches such as the formation of J-aggregates,t he absorption of organic molecules can be extended to longer wavelength.…”