910135-20-5Relevant academic research and scientific papers
Effects of carbon-metal-carbon linkages on the optical, photophysical, and electrochemical properties of phosphametallacycle-linked coplanar porphyrin dimers
Matano, Yoshihiro,Matsumoto, Kazuaki,Hayashi, Hironobu,Nakao, Yoshihide,Kumpulainen, Tatu,Chukharev, Vladimir,Tkachenko, Nikolai V.,Lemmetyinen, Helge,Shimizu, Soji,Kobayashi, Nagao,Sakamaki, Daisuke,Ito, Akihiro,Tanaka, Kazuyoshi,Imahori, Hiroshi
experimental part, p. 1825 - 1839 (2012/03/10)
5-(Diphenylphosphanyl)-10,15,20-triarylporphyrins (meso- phosphanylporphyrins) underwent complexations with palladium(II) and platinum(II) salts to afford phosphapalladacycle- and phosphaplatinacycle-fused coplanar porphyrin dimers, respectively, via regioselective peripheral β-C-H activation of the meso-phosphanylporphyrin ligands. The optical and electrochemical properties of these metal-linked porphyrin dimers as well as their porphyrin monomer/dimer references were investigated by means of steady-state UV-vis absorption/fluorescence spectroscopy, cyclic and differential pulse voltammetry, time-resolved spectroscopy (fluorescence and transient absorption lifetimes and spectra), and magnetic circular dichroism spectroscopy. All the observed data clearly show that the palladium(II) and platinum(II) linkers play crucial roles in the electronic communication between two porphyrin chromophores at the one-electron oxidized state and in the singlet-triplet intersystem-crossing process at the excited state. It has also been revealed that the C-Pt-C linkage makes more significant impacts on these fundamental properties than the C-Pd-C linkage. Furthermore, density functional theory calculations on the metal-linked porphyrin dimers have suggested that the antibonding dπ-pπ orbital interaction between the peripherally attached metal and adjacent pyrrolic β-carbon atoms destabilizes the highest occupied molecular orbitals of the porphyrin π-systems and accounts for the observed unique absorption properties. On the basis of these experimental and theoretical results, it can be concluded that the linear carbon-metal-carbon linkages weakly but definitely perturb the optical, photophysical, and electrochemical properties of the phosphametallacycle-linked coplanar porphyrin dimers.
Regioselective β-metalation of meso-phosphanylporphyrins. Structure and optical properties of porphyrin dimers linked by peripherally fused phosphametallacycles
Matano, Yoshihiro,Matsumoto, Kazuaki,Nakao, Yoshihide,Uno, Hidemitsu,Sakaki, Shigeyoshi,Imahori, Hiroshi
, p. 4588 - 4589 (2008/09/20)
meso-Diphenylphosphanylporphyrins were successfully prepared via Pd-catalyzed C-P cross-coupling reaction of the corresponding meso-iodoporphyrins with diphenylphosphane. The meso-phosphanylporphyrins underwent regioselective metalation at the β carbon to produce novel classes of porphyrin dimers linked by peripherally fused phosphametallacycles. A Pd-mononucler complex was structurally characterized by X-ray crystallography, which revealed a flat structure of the Pd-linked porphyrin π systems. Both experimental and theoretical results demonstrate that the orbital interaction between the pyrrolic pπ orbitals and the metal dπ orbital affects optical and electrochemical properties of the metal-linked coplanar porphyrin dimers. Copyright
