Unprecedented Pendant Group Exchange of a Porphyrinato Platinum(II) in Benzonitrile

5-(4-cyanophenyl)-10,15,20-triphenylporphyrinato platinum(II) (3) and 5-(4-methoxycarbonylphenyl)-10,15,20triphenylporphyrinato platinum(II) (2) were isolated from a reaction of 5-(4-methoxycarbonylphenyl)-10,15,20-triphenyl porphyrin (1) with K2[PtCl4] in benzonitrile. Seemingly, 3 was generated through the functional group substitution reaction of the phenyl group of tetraphenylporphyrin during platinum ion insertion into 1 and was characterized by 1H NMR, mass spectroscopy, elemental analysis, and X-ray crystallography.