117256-47-0Relevant academic research and scientific papers
Nonisotropic excitation energy transport in organized molecular systems: Monte Carlo simulation-based analysis of fluorescence and fluorescence anisotropy decay
Yatskou, Mikalai M.,Donker, Harry,Novikov, Eugene G.,Koehorst, Rob B. M.,Van Hoek, Arie,Apanasovich, Vladimir V.,Schaafsma, Tjeerd J.
, p. 9498 - 9508 (2001)
An improved application is presented of the Monte Carlo method including simultaneous parameter fitting to analyze the experimental time-resolved fluorescence and fluorescence anisotropy decay of two organized molecular systems exhibiting a number of different, nonisotropic energy transfer processes. Using physical models and parameter fitting for these systems, the Monte Carlo simulations yield a final set of parameters, which characterize the energy transfer processes in the investigated systems. The advantages of such a simulation-based analysis for global parametric fitting are discussed. Using this approach energy transfer processes have been analyzed for two porphyrin model systems, i.e., spin-coated films of zinc tetra-(octylphenyl)-porphyrins (ZnTOPP) and the tetramer of zinc mono(4-pyridyl)triphenylporphyrin (ZnM(4-Py)TrPP). For the ZnTOPP film energy transfer rate constants of ～1 × 1012 s-1 and ～80 × 109 s-1 have been found, and are assigned to intra- and interstack transfer, respectively. For the tetramers, the transfer rate constants of 38 × 109 and 5 × 109 s-1 correspond to energy transfer to nearest and next nearest neighbor molecules, respectively. The results are in agreement with a Foerster type energy transfer mechanism.
Characterization of a 5-Pyridyl-10,15,20-triphenylporphyrinatozinc(II) Polymer
Shachter, Amy M.,Fleischer, Everly B.,Haltiwanger, R. Curt
, p. 960 - 961 (1988)
The long chain structure of a polymer of 5-pyridyl-10,15,20-triphenylporphyrinatozinc(II) was determined by u.v.-visible spectroscopy, proton n.m.r., and X-ray crystallography.
Synthesis, electrochemistry, and spectroelectrochemistry of a metalloporphyrin-viologen donor-acceptor diad
Barton, Matthew T.,Rowley, Natalie M.,Ashton, Peter R.,Jones, Christopher J.,Spencer, Nell,Tolley, Malcolm S.,Yellowlees, Lesley J.
, p. 3170 - 3175 (2007/10/03)
A new donor-acceptor (D-A) molecule, zinc 5-{N-[4-(l '-benzyl-4, 4'-bipyridinium-l-ylmethyl)benzyl]-4-pyridinio}-10, 15, 20-triphenylporphyrinate tris(hexafluorophosphate) has been synthesized. The diad and its precursors have fully been characterised by 'H and C NMR spectroscopy, mass spectrometry, UV/Visible spectroscopy and cyclic voltammetry. /;; situ UV/Visible and EPR measurements show that the site of the first and second electrochemical reductions is the benzyl viologen component of the molecule, whilst the third electron reduction process is associated with the porphyrin moiety. The first reduction process gave rise to an EPR signal due to the benzyl viologen radical, whilst the second caused the molecule to become diamagnetic. The third of these processes gave rise to a new EPR signal, which was found to correspond to the metalloporphyrin radical. The Royal Society of Chemistry 2000.
Perpendicularly Arranged Ruthenium Porphyrin Dimers and Trimers
Funatsu, Kenji,Kimura, Akira,Imamura, Taira,Ichimura, Akio,Sasaki, Yoichi
, p. 1625 - 1635 (2008/10/09)
A series of ruthenium(II) porphyrin dimers and trimers (carbonyl dimers, 1-4; carbonyl trimers, 5-7, bis(pyridyl) trimers, 8-10), having axial or bridging porphyrin ligands, were synthesized and characterized by 1H NMR and IR spectroscopy and mass spectrometry. An X-ray structural determination of RuII(OEP)(CO)(H2PyP3P) (1) (OEP = octaethylporphyrinato dianion, H2PyP3P = 5-pyridyl-10,15,20-triphenylporphyrinato dianion) was carried out. The axial porphyrin ligand is coordinated to the ruthenium porphyrin subunit obliquely. The Ru-N(Py) bond length is 2.237(4) ?, and the angle between the ruthenium porphyrin macrocycle and the pyridyl ring is 63.23(35)°. Crystallographic data for 1 are as follows: chemical formula C80H73N9ORu·CH2Cl 2, triclinic, P1, a = 14.954(5) ?, b = 25.792(5) ?, c = 10.124(3) ?, α = 90.21(2)°, β = 108.43(2)°, γ = 73.39(2)°, Z = 2, R(F) = 0.0674. 1H NMR signals of 2,6- and 3,5-pyridyl protons of the axial ligand porphyrins of the oligomers 1-10 showed significant upfield shifts, indicating that the axial porphyrin subunits are coordinated to the ruthenium porphyrin subunits through the pyridyl group in solution. UV-vis spectra revealed the presence of excitonic interaction between two axial ligand porphyrin subunits in the trimers 8-10. The MLCT bands from the central ruthenium(II) ions to the octaethylporphyrin rings were observed around 450 nm in 8 and 9. Cyclic voltammograms of the carbonyl dimers and trimers showed no redox waves of the ruthenium(II) ions, because the ruthenium(II) oxidation state of these complexes was significantly stabilized by the coordination of the axial CO ligands. On the other hand, bis(pyridyl) trimers exhibit the Ru(III/II) waves in the region of -0.12 to +0.15 V vs Ag/Ag+ reference electrode.
Coordination oligomers and a coordination polymer of zinc tetraarylporphyrins
Fleischer, Everly B.,Shachter, Amy M.
, p. 3763 - 3769 (2008/10/08)
The structure of (5-pyridyl-10,15,20-triphenylporphyrinato)zinc(II) (C43H27N5Zn) was determined by visible spectroscopy, proton NMR spectroscopy, fluorescence spectrophotometry, and X-ray crystallography. Spectroscopic results indicated that the pyridine on the porphyrin periphery was bound to the metal center of an adjacent porphyrin, thereby creating a polymer. The crystal structure of the ZnMPyTPP polymer revealed that the polymer was in a long chain, zigzag conformation with an unusual 25° tilt of the pyridine ring. The polymer crystallized in the monoclinic space group P21/c with a = 10.839 (3) A?, b = 19.124 (9) A?, c = 16.158 (6) A?, β = 90.32 (3)°, and Z = 4. For 2130 observed reflections, the refinement yielded R = 0.0626. The structure of the polymer in solution was shown to be similar to that in the solid state by NMR porphyrin ring current theory. Coordinated dimers and trimers were formed by the coordination of 5-pyridyl-10,15,20-triphenylporphyrin, 5,10-dipyridyl-15,20-diphenylporphyrin, or 5,15-dipyridyl-10,20-diphenylporphyrin with (5,10,15,20-tetraphenylporphyrinato)zinc(II) and were characterized by spectroscopic methods.
