87377-51-3Relevant academic research and scientific papers
A simple synthesis of pyridine-tethered porphyrins
Cammidge,Lifsey
, p. 6655 - 6656 (2000)
Zinc porphyrin 4, in which a pyridine ligand is tethered to the 3-position of a meso-phenyl substituent via a nine-atom spacer, has been synthesised and is found to exist as the intramolecularly bound complex in solution. (C) 2000 Elsevier Science Ltd.
Synthesis of long-wavelength absorbing porphyrin m-benzoic acids as molecular tectons for surface studies
Meindl, Alina,Ryan, Aoife A.,Flanagan, Keith J.,Senge, Mathias O.
, p. 1518 - 1541 (2017/08/02)
Porphyrins are becoming increasingly important building blocks in material science. This is due in part to several favorable characteristics; such as strong absorption into the infrared region, tunable electronic properties and the possibility to modify and define the porphyrin core in multiple ways. Herein we report synthetic methodologies for porphyrin-based molecular tectons for surface studies. The study aims to generate porphyrins with directional anchoring groups of different length and we report a library of long-wavelength absorbing porphyrins with a special focus on organometallic coupling reactions for the introduction of benzoic acid moieties as anchor groups.
Comparison between 5,10,15,20-tetraaryl- and 5,15-diarylporphyrins as photosensitizers: Synthesis, photodynamic activity, and quantitative structure-activity relationship modeling
Banfi, Stefano,Caruso, Enrico,Buccafurni, Loredana,Murano, Roberto,Monti, Elena,Gariboldi, Marzia,Papa, Ester,Gramatica, Paola
, p. 3293 - 3304 (2007/10/03)
The synthesis of a panel of seven nonsymmetric 5,10,15,20- tetraarylporphyrins, 13 symmetric and nonsymmetric 5,15-diarylporphyrins, and one 5,15-diarylchlorin is described. In vitro photodynamic activities on HCT116 human colon adenocarcinoma cells were evaluated by standard cytotoxicity assays. A predictive quantitative structure-activity relationship (QSAR) regression model, based on theoretical holistic molecular descriptors, of a series of 34 tetrapyrrolic photosensitizers (PSs), including the 24 compounds synthesized in this work, was developed to describe the relationship between structural features and photodynamic activity. The present study demonstrates that structural features significantly influence the photodynamic activity of tetrapyrrolic derivatives: diaryl compounds were more active with respect to the tetraarylporphyrins, and among the diaryl derivatives, hydroxy-substituted compounds were more effective than the corresponding methoxy-substituted ones. Furthermore, three monoarylporphyrins, isolated as byproducts during diarylporphyrin synthesis, were considered for both photodynamic and QSAR studies; surprisingly they were found to be particularly active photosensitizers.
Supramolecular complex composed of a covalently linked zinc porphyrin dimer and fulleropyrrolidine bearing two axially coordinating pyridine entities
D'Souza, Francis,Gadde, Suresh,Zandler, Melvin E.,Itou, Mitsunari,Araki, Yasuyuki,Ito, Osamu
, p. 2276 - 2277 (2007/10/03)
A zinc porphyrin dimer-fullerene supramolecular complex with a large association constant is assembled; efficient intramolecular photoinduced electron transfer from the singlet excited state of zinc porphyrin to the fullerene is observed.
Probing the donor-acceptor proximity on the physicochemical properties of porphyrin-fullerene dyads: "Tail-on" and "tail-off" binding approach
D'Souza,Deviprasad,El-Khouly,Fujitsuka,Ito
, p. 5277 - 5284 (2007/10/03)
A new approach of probing proximity effects in porphyrin-fullerene dyads by using an axial ligand coordination controlled "tail-on" and "tail-off" binding mechanism is reported. In the newly synthesized porphyrin-fullerene dyads for this purpose, the donor-acceptor proximity is controlled either by temperature variation or by an axial ligand replacement method. In o-dichlorobenzene, 0.1 M (TBA)ClO4, the synthesized zincporphyrin-fullerene dyads exhibit seven one-electron reversible redox reactions within the accessible potential window of the solvent and the measured electrochemical redox potentials and UV-visible absorption spectra reveal little or no ground-state interactions between the C60 spheroid and porphyrin π-system. The proximity effects on the photoinduced charge separation and charge recombination are probed by both steady-state and time-resolved fluorescence techniques. It is observed that in the "tail-off" form charge-separation efficiency changes to some extent in comparison with the results obtained for the "tail-on" form, suggesting the presence of some through-space interactions between the singlet excited zinc porphyrin and the C60 moiety in-the "tail-off" form. The charge separation rates and efficiencies are evaluated from the fluorescence lifetime studies. The charge separation via the singlet excited states of zinc-porphyrin in the studied dyads is also confirmed by the quick rise-decay of the anion radical of the C60 moiety within 20 ns. Furthermore, a long-lived ion pair with lifetime of about 1000 ns is also observed in the investigated zinc porphyrin-C60 dyads.
Intramolecular Electron Transfer in Donor-Acceptor Systems. Porphyrins Bearing Trinitroaryl Acceptor Group
Maiya, G. Bhaskar,Krishnan. V.
, p. 5225 - 5235 (2007/10/02)
Porphyrins bearing picryl group in ortho, meta, and para positions of one of the mesoaryl groups of tetraphenylporphyrin (TPP) have been synthesized in the free-base form.The metal derivatives of the free-base picrylporphyrins (PPc) have been prepared.The broadened Soret absorption, the decreased optical absorbance values of Q bands, and the reduced singlet emission quantun yields of PPc indicate the existence of intramolecular interaction.The extent of this interaction is found to be greater than those observed for the intermolecular systems and varies with the position at which the picryl moiety is attached to the porphyrin as ortho > meta > para.The energies of the redox states, E(CT) of P+Pc-, calculated from the electrochemical redox potentials depend on the nature of the metal ion as free-base PPc > CuPPc > ZnPPc.The nature of intramolecular interaction between the picryl moiety and porphyrin unit is essentially ?-? (CT).Conclusive evidence for light-induced electron transfer in ZnPPc is presented from EPR studies.The decay profiles of the EPR signals vary with the position of the picryl moiety as ortho para meta.Computer simulation of structures substantiated by the 1H NMR results point out the restricted conformational freedom of the picryl moiety in ZnPPc.Arguments based on symmetry considerations of HOMO of the excited singlet state PPc and LUMO of picryl group indicate plane-to-plane orientation of the donor and acceptor in the picrylporphyrins.
