Ruthenium(II) Octaphenylporphyrazine Complexes with Mixed Axial Ligands: Peculiarities of Their Formation and Spectral Properties

Abstract

A series of new axially bis‐coordinated (octaphenylporphyrazinato)ruthenium(II) complexes {[(Ph8Pz)RuL2], L = cyclohexyl isocyanide, CyNC, (1b); 4,4′‐bipyridine, bpy, (2c); N‐methylimidazole, CH3Im, (3a)} was prepared and characterized. The reaction of the bis‐isocyanide adducts [(Ph8Pz)Ru(tBuNC)2] (1a) or [(Ph8Pz)Ru(CyNC)2] (1b) with monodentate N‐heterocycles gave, under certain conditions, the mixed‐ligand complexes [(Ph8Pz)Ru(Py)(tBuNC)] (4a), [(Ph8Pz)Ru(Py)(CyNC)] (4b) and [(Ph8Pz)Ru(CH3Im)(CyNC)] (3b). The reaction of 1a or 1b with an excess of bidentate 4,4′‐bipyridine under the same conditions resulted in the formation of the corresponding dimeric species [(Ph8Pz)Ru(tBuNC)]2(μ‐bpy) (2a) and [(Ph8Pz)Ru(CyNC)]2(μ‐bpy) (2b) in high yield. The structures of all the complexes were unambiguously proved by 1H NMR spectroscopy, and the possibility of their self‐assembly is discussed. All mixed‐ligand compounds were also characterized by UV/Vis and IR spectroscopy, as well as elemental analysis. The 1H NMR spectra of these compounds are discussed in detail. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Phosphorus(v) tetrapyrazinocorrolazines bearing axial aryloxy groups as pH-sensitive fluorophores and photosensitizers

“…Such upfield shift of the protons in the axial groups is due to the strong shielding effect of the ring current in the aromatic macrocycles. 49,50 The signals of ortho -protons are shifted upfield by ∼4.2 ppm and are additionally split due to spin–spin interactions with phosphorus ion. Similar shifts and splitting were observed in the case of aryloxy-substituted P V porphyrins.…”