Zinc-coordination oligomers of phenanthrolinylporphyrins

We report the synthesis of mono- and bisphenanthrolinylporphyrins 5-(9-carboxy-1,10-phenanthroline-2),15-(p-tolyl)-2,8,12,18-tetraethyl-3,7,13,17-tetramethylporphyrin (MPPc) and 5,15-bis(9-carboxy-1,10-phenanthroline-2)-2,8,12,18-tetraethyl-3,7,13,17-tetramethylporphyrin (BPPc), respectively. The formation of dimers and oligomers, with MPPc and BPPc, respectively, upon exposure to zinc acetate is described. Oligomerization of the porphyrins was monitored spectrophotometrically, and a kinetic study was performed to estimate the average oligomer chain length.