Rutheniurn(II) meso-tetra-(benzo-15-crown-5)-porphyrinates:: Synthesis and spectroscopic investigation

The synthesis of novel ruthenium(II) meso-tetra-(benzo-15-crown-5)-porphyrinates, meso-[(B15C5)(4)Por]Ru(CO)(MeOH) (1) and meso-[(B15C5)(4)Por]Ru(L)(2) (2)-(4) (meso-[(B15C5)(4)Por](2)= 5, 10, 15,20-tetrakis-(benzo-15-crown-5)-porphyrinato-dianion; L = pyridine (py), pyrazine (pyz), 4,4'-bipyridyl (4,4'-bpy)), where CO and MeOH, or two N-donor ligands are axially coordinated to the central metal, are reported. The metalation of the free ligand performed by the reaction of Ru-3(CO)(12) with meso-[(B15C5)(4)Por]H-2 in 1,2,4-trichlorobenzene (TCB, bp = 215 degrees C), gives (1) in a high yield. The synthesis of (2)-(4) involves the decarborylation of (1) with trimethylamine N-oxide ((CH,),NO) in the presence of an excess of the N-donor ligand. The coordination of the axially bonded ligands is evidenced by different spectroscopic data. Copyright (c) 2007 Society of Porphyrins & Phthalocyanines.