Tetratellura[36]octaphyrin(1.1.1.1.1.1.1.1) Metalation: From Dynamic Behavior to Rigid Chiral Figure-of-Eight Molecule; Activation of the C-Te Bond by Ruthenium.

The large expanded telluraporphyrin, tetratellura[36]octaphyrin(1.1.1.

Heterobimetallic 21,23-dimetallaporphyrin: activation of metal-metal interactions within the porphyrinoid macrocycle.

Two core-modified porphyrins containing metal atoms, namely platinum(II) or platinum(IV) and rhodium(III), in place of two NH units, have been obtained by a post-synthetic modification of the 21,23-ditelluraporphyrin. The products of the tellurium-to-metal exchange, 21-platina-23-rhodaporphyrins, incorporate rhodacyclopentadiene and platinacyclopentadiene units with the metal atoms facing each other. The two molecules exhibit different degrees of metal-metal interaction depending on the oxidation state of platinum, with the NBO bond order being 0.

Metalation of Tellurophene: Reactivity of 21,23-Ditelluraporphodimethene toward Palladium(II), Platinum(II), and Rhodium(I).

Ditelluraporphodimethene, a nonaromatic porphyrinoid containing two tellurophene rings, reacted with palladium(II), platinum(II), and rhodium(I) following two different paths. Palladium(II) formed bonds to two tellurium donors of the macrocycle, yielding a side-on coordination compound, with a square planar (TeCl) metal ion environment. An alternative reaction path has been observed for ditelluraporphodimethene with platinum(II) or rhodium(I) in high boiling solvents.

Two Rhodium(III) Ions Confined in a [18]Porphyrin Frame: 5,10,15,20-Tetraaryl-21,23-dirhodaporphyrin.

Invited for the cover of this issue is the group of Ewa Pacholska-Dudziak at the University of Wroclaw. The image depicts two rhodium atoms being fixed into the skeleton of 21,23-dirhodaporphyrin in place of two core nitrogen donors. Read the full text of the article at 10.

Two Rhodium(III) Ions Confined in a [18]Porphyrin Frame: 5,10,15,20-Tetraaryl-21,23-Dirhodaporphyrin.

Tetraaryl-21,23-dirhodaporphyrin and a series of related monorhodaporphyrins have been obtained by tellurium-to-rhodium exchange in a reaction of tetraaryl-21,23-ditelluraporphyrin with [RhCl(CO) ] . These organometallic metallaporphyrins contain rhodium(III) centers embedded in rhodacyclopentadiene rings, incorporated within the porphyrin frames. The skeletons of 21,23-dirhodaporphyrin and 21-rhoda-23-telluraporphyrin are strongly deformed in-plane from the rectangular shape typical for porphyrins, due to rhodium(III) coordination preferences, the large size of the two core atoms, and the porphyrin skeleton constrains.

Chemistry inside a Porphyrin Skeleton: Platinacyclopentadiene from Tellurophene.

Platinum(II) binds to 21,23-ditelluraporphyrin forming a side-on complex, which can be easily transformed into an aromatic metallaporphyrin, that is, 21-platina-23-telluraporphyrin, with a platinacyclopentadiene unit built in the porphyrin skeleton in place of one pyrrole ring. The central platinum(II) ion with a CCNTe square-planar coordination sphere can be oxidized to platinum(IV) by chlorine, bromine, methyl iodide or allyl chloride to yield octahedral complexes. All platinatelluraporphyrins show dynamic behavior involving the platinum ion coordination sphere fluxionality and the porphyrin skeleton deformation, both in-plane and out-of-plane, as demonstrated by H NMR spectroscopy.

28-Hetero-2,7-Naphthiporphyrins: Horizontal Expansion of the -Benziporphyrin Macrocycle.

Replacement of the -phenylene moiety of -benziporphyrins with the 2,7-naphthalenyl subunit yielded 28-hetero-2,7-naphthiporphyrins-macrocycles that can be considered as expanded carbaporphyrinoids. This group retains some features of parent -benziporphyrins, but due to larger size and different shape of the macrocyclic cavity, their coordination properties are different. Upon reduction and conformational rearrangement the 28-thia- and 28-selena-2,7-naphthiporphyrin form organophosphorus(V) complexes.

Expanded Porphyrin Contraction: From [22]Triphyrin(6.6.0) to [22]Triphyrin(6.5.0).

An expanded triphyrin containing a bipyrrole moiety and annulene links, namely tetraphenyl-[22]triphyrin(6.5.0), 2, has been synthesized.

Shaping a Porphyrinoid Frame by Heteroatoms Extrusion: Formation of an Expanded [22]Triphyrin(6.6.0).

An aromatic expanded triphyrin, [22]triphyrin(6.6.0) 2, containing a pyrrole unit, a bipyrrole moiety, and annulene links, was obtained from a tellurium-containing precursor meso-tetraaryl-26,28-ditellurasapphyrin 1.

Flexible Porphyrinoids.

This review underscores the conformational flexibility of porphyrinoids, a unique class of functional molecules, starting from the smallest triphyrins(1.1.1) via [18]porphyrins(1.

Incorporation of a Phenanthrene Subunit into a Sapphyrin Framework: Synthesis of Expanded Aceneporphyrinoids.

32-Hetero-5,6-dimethoxyphenanthrisapphyrins-macrocycles that link structural features of polycylic aromatic hydrocarbons and expanded porphyrins-were obtained in a straightforward [3+1] condensation reaction of dimethoxyphenanthritripyrrane and 2,5-bis(arylhydroxymethyl)heterocyclopentadienes. The highly folded conformation of formally 4 n π-electron macrocycles causes them to manifest only limited macrocyclic π conjugation as explored by means of NMR spectroscopic and X-ray structural analyses, and supported by DFT calculations. Although protonation does not change their π-conjugation characteristics, the cleavage of ether groups at the phenanthrenylene moiety yields nonaromatic 32-hetero-5,6-dioxophenanthrisapphyrins.

Incorporation of the 1,5-naphthalene subunit into heteroporphyrin structure: toward helical aceneporphyrinoids.

5,10,15,20-Tetraaryl-22-hetero-1,5-naphthiporphyrins, which contain a 1,5-naphthylene moiety instead of one pyrrole embedded in the macrocyclic framework of heteroporphyrins, were obtained by the [3 + 1] approach using the 1,5-naphthylene analogue of tripyrrane (1,5-bis(phenyl(2-pyrolyl)methyl)naphthalene) and 2,5-bis(arylhydroxymethyl)heterocyclopentadiene (heterocyclopentadiene: thiophene, selenophene, tellurophene). The steric constraints, imposed by the substitution mode of the 1,5-naphthylene building block, resulted in the specific helical conformation of 22-hetero-1,5-naphthiporphyrins. The spectroscopic and structural properties of these aceneporphyrinoids indicate a lack of macrocycle aromaticity.

The role of nitrogen bridges perturbing the photophysical properties in the porphyrin framework.

We have investigated the photophysical properties of vacataporphyrins possessing systematically controlled butadiene linkers on their π-electron pathways.

Vacata- and divacataporphyrin: new photosensitizers for application in photodynamic therapy-an in vitro study.

Background And Objective: The photodynamic therapy is a well-known method of treatment of both malignant tumors and non-tumor lesions in human patients. In the present study, we aimed at evaluating the in vitro efficacy of the new photosensitizing agents, vacataporphyrin (VP), and divacataporphyrin (DVP).

Materials And Methods: The effectiveness of VP and DVP was compared to well-known photosensitizers, that is, hematoporphyrin derivative (HPD) and chlorin e6 (Ce6) in identical in vitro conditions.

Iron(II) vacataporphyrins: a variable annulene conformation inside a regular porphyrin frame.

5,10,15,20-Tetraaryl-21-vacataporphyrin (1), an annulene-porphyrin hybrid containing a butadiene fragment in the macrocycle perimeter, gives paramagnetic iron(II) complexes 2. The porphyrin 1 is devoid of one donor atom of the coordination core; hence, metal ion is bound in the macrocyclic cavity by only three pyrrolic nitrogen atoms. The coordination sphere in 2-X (where X = Cl, Br, I) is completed by a halide anion.

A flexible porphyrin-annulene hybrid: a nonporphyrin conformation for meso-tetraaryldivacataporphyrin.

An annulene-porphyrin hybrid, the diaaza-deficient porphyrin 5,10,15,20-tetraaryl-21,23-divacataporphyrin, has been synthesized by an extrusion of tellurium atom(s) from 5,10,15,20-tetraaryl-21,23-ditelluraporphyrin under treatment with HCl. In addition, a monoaza-deficient 5,10,15,20-tetraaryl-21-tellura-23-vacataporphyrin was formed in the same reaction. The two new members of the vacataporphyrin family were characterized by X-ray crystallography, as well as UV/Vis and NMR spectroscopy.

N-fusion approach in construction of contracted carbaporphyrinoids: formation of N-fused telluraporphyrin.

Insertion of PCl(3) into 5,10,15,20-tetraaryl-21-telluraporphyrin leads to a phosphorus complex of N-fused dihydrotelluraporphyrin with an inverted tellurophene ring. Its CNN coordination core places the macrocycle in the family of contracted carbaporphyrinoids. A cycle of direct transformations affords an elegant triangle of three mutually convertible N-fused porphyrinoids, with distinct spectroscopic features: antiaromatic, nonaromatic and aromatic.

Palladium vacataporphyrin reveals conformational rearrangements involving Hückel and Möbius macrocyclic topologies.

5,10,15,20-Tetraaryl-21-vacataporphyrin (butadieneporphyrin, an annulene-porphyrin hybrid) which contains a vacant space instead of heteroatomic bridge acts as a ligand toward palladium(II). The metal ion of square-planar coordination geometry is firmly held via three pyrrolic nitrogen atoms where the fourth coordination place is occupied by a monodentate ligand or by an annulene part of vacataporphyrin. The macrocycle reveals the unique structural flexibility triggered by coordination of palladium.

Cadmium(II), nickel(II), and zinc(II) complexes of vacataporphyrin: a variable annulene conformation inside a standard porphyrin frame.

5,10,15,20-Tetraaryl-21-vacataporphyrin, 1 (butadieneporphyrin, annulene-porphyrin hybrid), which contains a vacant space instead of heteroatomic bridge, gives diamagnetic zinc(II) 1-ZnCl and cadmium(II) 1-CdCl and paramagnetic nickel(II) 1-NiCl complexes. A metal ion is bound in the macrocyclic cavity by three pyrrolic nitrogens. Coordination imposes a steric constraint on the geometry of the ligand and leads to two stereoisomers with a butadiene fragment oriented toward 1-MCl-i or outward 1-MCl-o of the macrocyclic center.