COORDINATION OLIGOMERS AND A COORDINATION POLYMER OF ZINC TETRAARYLPORPHYRINS

The structure of (5-pyridyl-10,15,20-triphenylporphyrinato)zinc(II) (C43H27N5Zn) was determined by visible spectroscopy, proton NMR spectroscopy, fluorescence spectrophotometry, and X-ray crystallography. Spectroscopic results indicated that the pyridine on the porphyrin periphery was bound to the metal center of an adjacent porphyrin, thereby creating a polymer. The crystal structure of the ZnMPyTPP polymer revealed that the polymer was in a long chain, zigzag conformation with an unusual 25-degrees tilt of the pyridine ring. The polymer crystallized in the monoclinic space group P2(1)/c with a = 10.839 (3) angstrom, b = 19.124 (9) angstrom, c = 16.158 (6) angstrom, beta = 90.32 (3)-degrees, and Z = 4. For 2130 observed reflections, the refinement yielded R = 0.0626. The structure of the polymer in solution was shown to be similar to that in the solid state by NMR porphyrin ring current theory. Coordinated dimers and trimers were formed by the coordination of 5-pyridyl-10,15,20-triphenylporphyrin, 5,10-dipyridyl-15,20-diphenylporphyrin, or 5,15-dipyridyl-10,20-diphenylporphyrin with (5,10,15,20-tetraphenylporphyrinato)zinc(II) and were characterized by spectroscopic methods.