Search results for "PORP"

Improved routes for the synthesis of face-to-face bismacrocycles in porphyrin and corrole series

2005

Face-to-face bismacrocycles involving porphyrinoid species are still of great interest owing to their versatile properties. Despite the fact that their syntheses generally involve several steps, numerous modifications have been made in their synthetic pathways thus allowing their preparation in gram quantities. Here we report on recent improvements we could propose especially for the synthesis of bisporphyrin, biscorrole and porphyrin-corrole derivatives.

Theoretical Studies of the Electronic Spectra of Organic Molecules

1995

The complete active space (CAS) SCF method in conjunction with multiconfigurational second-order perturbation theory (CASPT2) has been used to study the electronic spectra of a large number of molecules. The wave functions and the transition properties are computed at the CASSCF level, while dynamic correlation contributions to the excitation energies are obtained through the perturbation treatment. The methods yield energies, which are accurate to at least 0.2 eV, except in a few cases, where the CASSCF reference function does not characterize the electronic state with sufficient accuracy. The applications comprise: the polyenes from ethene to octatetraene (cis- and trans-forms); a number …

Novel Porphyrin-cholic Acid Conjugates as Receptors for Biologically Important Anions

2007

ChemInform Abstract: Synthesis and Electrode Reactions of Difluorogermanium(IV) Porphyrins. Molecular Stereochemistry and Crystal Structure of Difluo…

1988

The difluorogermanium(IV) porphyrins [GeF2(P)][P = 2,3,7,8,12,13,17,18-octaethylporphyrinate(2–)(oep), 5,10,15,20-tetraphenylporphyrinate(2–)(tpp), or 5,10,15,20-tetra-p-tolylporphyrinate(2–)(tptp)] have been prepared by reacting hydrogen fluoride with the appropriate dichloro derivative [GeCl2(P)]. The complexes were characterized by elemental analysis, 1H n.m.r., i.r., and u.v.–visible spectroscopy. The electrochemical behaviour was investigated in non-aqueous media while spectroelectrochemistry and e.s.r. were used to characterize the oxidized and reduced complexes. Each complex could be reversibly oxidized or reduced by one electron. In each case these electron additions or abstractions…

[5,10,15,20-Tetrakis(4-tert-butylphenyl)-porphyrinato-κ4N] zinc(II) toluene solvate

2007

The structure of the title compound, [Zn(C60H60N4)]·C7H8, represents a typical clathrate containing a host mol­ecule of [5,10,15,20-tetra­kis(4-tert-butyl­phen­yl)­porphyrin­ato]­zinc(II) and a toluene guest mol­ecule. The Zn atom occupies an inversion center and exhibits ideal square-planar coordination, while the porphyrin group remains perfectly flat. The toluene mol­ecule lies on an inversion center and is disordered.

Bis- and trisporphyrin bio-inspired models for bacterial antennas and photosystems

2011

This review presents the synthetic aspects and photophysical properties of trimeric systems constructed with a first unit consisting of a cofacial porphyrin and then of another porphyrin attached as a side arm. Two scenarios are dealt with. The first one is the case where the three chromophores are different, called donor 1–donor 2–acceptor, specifically where the cofacial fragment is composed of donor 1 and donor 2, and the side arm is the acceptor. They are considered as models for the apo-proteins used in the LH II (light harvesting device) in the purple photosynthetic bacteria. The second one is the case where the chromophores of the cofacial bisporphyrin residue are identical and are …

Photoinduced electron transfer in supramolecular complexes of a π-extended viologen with porphyrin monomer and dimer

2012

A π-extended viologen has been synthesized, forming supramolecular complexes with a freebase tetraphenylporphyrin (H2TPP) and the cofacial porphyrin dimer with an anthracene spacer [H4(DPA)] through π–π interaction in benzonitrile (PhCN). Formation of the H2TPP-BHV2+ supramolecular complex was probed by UV-vis and fluorescence spectra. The fluorescence of H2TPP was strongly quenched by electron transfer from the singlet excited state (1H2TPP*) to BHV2+ in the supramolecular complex. The transient absorption spectrum of the charge-separated (CS) state (H2TPP•+ and BHV•+) was successfully detected by the laser flash photolysis measurements of the H2TPP-BHV2+ supramolecular complex in PhCN. Th…

Origin of the temperature dependence of the rate of singlet energy transfer in a three-component truxene-bridged dyads

2014

We report a truxene-based dyad built upon one donor (tri-meso-phenylzinc(II)porphyrin) and two acceptors (octa-β-alkylporphyrin free base) in which the donor exhibits free rotation around a Ctruxene-Cmeso single bond at 298 K in fluid solution but not at 77 K in a glass matrix, whereas the acceptors have very limited motion as they are blocked by β-methyl groups. This case is interesting because all the structural and spectroscopic parameters affecting the rate for singlet energy transfer according to a Förster Resonance Energy Transfer are only weakly temperature dependent, leaving only the Dexter mechanism explaining the larger variation in rate of energy transfers with the temperature h…

New Porphyrin/Fe-Loaded TiO2 Composites as Heterogeneous Photo-Fenton Catalysts for the Efficient Degradation of 4-Nitrophenol

2013

A new class of porphyrin(Pp)/Fe co-loaded TiO2 composites opportunely prepared by impregnation of [5,10,15,20-tetra(4-tert-butylphenyl)] porphyrin (H2Pp) or Cu(II)[5,10,15,20-tetra(4-tert-butylphenyl)] porphyrin (CuPp) onto Fe-loaded TiO2 particles showed high activities by carrying out the degradation of 4-nitrophenol (4-NP) as probe reaction in aqueous suspension under heterogeneous photo-Fenton-like reactions by using UV-visible light. The combination of porphyrin-Fe-TiO2 in the presence of H2O2 showed to be more efficient than the simple bare TiO2 or Fe-TiO2.

Synthesis of porphyrin-bis(polyazamacrocycle) triads via Suzuki coupling reaction

2014

Suzuki–Miyaura cross-coupling reaction has been used for the synthesis of tricyclic architectures based on trans-A2B2-porphyrins and bisaminal-protected polyazamacrocycles which are linked directly or by a p-phenylene spacer. This modular approach allowed the synthesis of ligands with various substituted porphyrin macrocycles and bisaminal-protected tetraazamacrocycles possessing different cavity sizes. These molecules can be assembled into dimers using a DABCO linker. Deprotection of these compounds afforded porphyrin-bis(polyazamacrocycle) triads.