Inorganic Chemistry, Vol.45, No.17, 6875-6883, 2006
Structural, redox, and photophysical studies of the tetra(pyridyl)porphyrin complex containing four (2,2'-bipyridine)(2,2': 6',2''-terpyridine)ruthenium(II) groups
New hybrid complexes of polypyridyl ruthenium and pyridylporphyrins have been prepared by the coordination of pyridyl nitrogens to the ruthenium centers. A 1:4 hybrid complex, [{Ru(bpy)(trpy)}(4)(mu(4)-H2Py4P)](8+) ([1](8+)) (bpy) 2,2 >-bipyridine; trpy) 2,2 >: 6 >, 2 >>- terpyridine; H2Py4P) 5,10,15,20-tetra(4-pyridyl) porphyrin), has been characterized by the single-crystal X-ray diffraction method. A 1:1 complex, [{Ru(bpy)(trpy)}( H2PyT3P)](2+) ([2](2+)) (H2PyT3P= 5-(4-pyridyl) tritolylporphyrin) has also been prepared. The Soret band of the porphyrin ring shifts to longer wavelength with some broadening, the extent of the shift being larger for [1](8+). Cyclic voltammograms of the two complexes show simple overlap of the component redox waves. The complexes are weakly emissive at room temperature, which becomes stronger at lower temperatures. While [1](8+) at > 140 K and [ 2] 2+ at 77 - 280 K show only porphyrin fluorescence, [1](8+) at < 140 K shows ruthenium and porphyrin phosphorescence, in addition to the porphyrin fluorescence.