Synthesis and Structure of Phosphorus(V) Octaethylporphyrins That Contain a .sigma.-Bonded Element-Carbon Bond: Characterization of a Porphyrin Bearing an R-P:O Bond and Relation of the Ruffling of the Porphyrin Core with the Electronegativity of the Axial Ligands

Synthesis and properties of group 15 element porphyrin peroxides

“…The experiment between antimony porphyrin hydroperoxide (16-ClO 4 ) and the corresponding phosphorus porphyrin hydroperoxide (26-OTf) under similar conditions clearly indicated that 26-OTf was much more reactive to triphenylphosphine than Recently, we reported that (OEP)MR(‫ס‬O) (M‫ס‬P, As, R‫ס‬Me, Et, Ph) were found to be almost planar and very stable in the case of the phosphorus [40] and arsenic porphyrins [41,42], but the corresponding antimony compound could not be isolated [33,34]. Therefore, we concluded that the higher reactivity of phosphorus and arsenic hydroperoxides could be due to the stability of the M‫ס‬O bonding system itself and also due to the stability that might be gained by the change of the shape of the molecules from ruffled [(OEP)P(R)(OH)]…”

Lead structures for applications in photodynamic therapy. 5. Synthesis and biological evaluation of water soluble phosphorus(V) 5,10,15,20-tetraalkylporphyrins for PDT

“…Here, we present the use of P(V) porphyrin complexes which offer such a possibility, as they allow not only the preparation of new drug candidates but simple improvements of existing drugs through P(V) complexation, i.e., water solubility [18], better uptake and potentially less side effects. P(V) porphyrin complexes are known but their exploitation in terms of PDT has been limited thus far [18,19,20,21,22,23,24,25]. We found that through P(V) complexation of simple meso tetrasubstituted porphyrins both the water solubility and the in vitro cytotoxicity of the photosensitizer can be drastically improved with respect to the non-complexed form.…”

“…Meso aryl and β-octaethyl P(V) porphyrins have been prepared before, mostly for coordination studies, redox chemistry investigations, and structural analyses [19,20,21,22,23,24]. The procedure we adopted followed that developed for P(V) insertion of 2,3,7,8,12,13,17,18-octaethylporphyrin derivatives, whereby PCl 3 acts as a more effective reagent for insertion over POCl 3 due to a lower phosphorus oxidation state [23,24].…”

“…The procedure we adopted followed that developed for P(V) insertion of 2,3,7,8,12,13,17,18-octaethylporphyrin derivatives, whereby PCl 3 acts as a more effective reagent for insertion over POCl 3 due to a lower phosphorus oxidation state [23,24]. Our initial studies to prepare P(V) alkylporphyrins gave mixtures of the chloro and hydroxide complexes.…”

Electrochemistry of hexacoordinate silicon(IV) porphyrin complexes

“…The degree of ruffling is inversely related to the metal-nitrogen bond distance, which in turn is directly related to the electronegativity of the axial ligand. A more electronegative axial ligand will result in a stronger (shorter) metal-ligand bond and therefore longer metal-nitrogen bonds and a less ruffled porphyrin ring [46] which is easier to reduce. Silicon(iv) porphyrin complexes readily conform to this trend.…”