225376-39-6Relevant articles and documents
Synthesis and characterization of mono- and dinuclear phenanthroline- extended tetramesitylporphyrin complexes as well as UV-Vis and EPR studies on their one-electron reduced species
Matlachowski, Corinna,Schwalbe, Matthias
, p. 3490 - 3503 (2013/04/10)
The syntheses of mononuclear compounds based on the fused porphyrin phenanthroline ligand (H2-1) and their corresponding dinuclear porphyrin bis-bipyridine ruthenium complexes are reported. The extended π-system of the ligand is able to store electron equivalents as could be proven by the single electron reduction with KC8 (and/or Na(Hg)) followed by subsequent UV-Vis and EPR analysis. Electron reduction could also be achieved under light illumination in a dichloromethane-triethylamine mixture. The two coordination spheres of the ligand are different so that mononuclear or (hetero)dinuclear complexes can be isolated depending on the reaction conditions. We could successfully introduce Zn, Cu and Pd into the porphyrinic unit leading to a series of mononuclear (M-1) compounds. Further, we could attach the bis-(4,4′-di-tert-butyl-2,2′-bipyridine) ruthenium fragment (Ru(tbbpy)22+) to obtain dinuclear (M-1-Ru) metal complexes. In the case of Zn-1 an X-ray crystal structure could be obtained confirming the selective metallation in the porphyrinic unit. All metal complexes were isolated and characterized with standard analytical tools (elemental analysis, mass spectrometry and NMR (or EPR) spectroscopy).
Neocuproine-extended porphyrin coordination complexes. 2. Spectroscopic properties of the metalloporphyrin derivatives and investigations into the HOMO ordering
Vannelli, Tommaso A.,Karpishin, Timothy B.
, p. 340 - 347 (2008/10/08)
The synthesis of a porphyrin compound, 1, containing a 2,9-dimethyl-1,10-phenanthroline moiety that is fused at the β-pyrrole positions is reported. The absorption spectra of the free-base, copper(II), and zinc(II) derivatives have been studied. On the basis of absorption band intensities, the HOMO of the free base (H21) and its copper and zinc complexes (Cu1 and Zn1) was determined to be of a(1u) symmetry. Relative to H21, compounds Cu1 and Zn1 show enhanced spectral changes upon external metal ion binding. Although the HOMO is the same in all three compounds, the energy gap between the two highest occupied orbitals is greater for Cu1 and Zn1 than it is for the free-base compound. Several metal ions (Ni2+, Cu+, Cu2+, Zn2+, Li+) were examined in their binding to the phenanthrolinic group by measuring the resulting changes in the absorption spectra. It is shown that the observed changes in the absorption spectra are insensitive to the nature of the metal ion coordinated by the phenanthroline moiety. Significant differences in the absorption and emission spectra between Zn1 and [Zn(Zn1)2]2+ clearly demonstrate that the porphyrin π-system is strongly affected by the binding of metal ions at the fused phenanthrolinic moiety.
