A flexible expanded heterocorrole: Tellura[22]porphyrin(6.1.1.0)

Abstract

An expanded heterocorrole, meso-tetraaryl-tellura[22]porphyrin(6.1.1.0), containing a bipyrrole moiety and a six-carbon long link, has been synthesized. The reaction path proceeds through a controlled acid-promoted extrusion of one tellurium atom from meso-aryl-26,28-ditellurasapphyrin, leading to a structure where one tellurophene ring of the substrate is replaced by a bridging acyclic four-carbon unit. This aromatic porphyrin-annulene hybrid is conformationally flexible in solution, on account of the C4 unit adopting two different configurations: trans–cis–trans or all-trans. Studies of the dynamic behavior of tellura[22]porphyrin(6.1.1.0) in solution were performed by means of 1H and 125Te NMR spectroscopy. The X-ray structure of the all-trans form with trapezoid macrocyclic skeleton is also presented.

The p-Metal Porphyrins: from Specificity of Properties to Application in Medicine, Catalysis, and Optoelectronics

“…Most notably, they combine interesting spectroscopic and chemical properties as the luminescent properties and particular oxophilicity with the 14 group porphyrin complexes [26] or the coordination with two and three porphyrin N atoms only with the boron and tellurium complexes, respectively. [47] Many works [48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65] can be cited, in which using the maingroup porphyrin/phthalocyanine complexes as aluminumsubstituted heme, anticancer/phototeranoctic agents, prophotosensitizers/singlet oxygen sensitizers, template agents in the tetrapyrrole macrocycle synthesis, electron acceptor materials for organic electronics, and chemosensors were studied. Generalizations in the area under consideration have been undertaken in three reviews [27,48,66] where the earlier ones was mentioned and, in part, in two more reviews.…”