Synthesis and Isomerization of N‑Fused Tetraphenylporphyrin Ruthenium(II) Complexes

Three possible isomers of N-fused tetraphenylporphyrin ruthenium complexes, Ru­(NFTPp)­Cl­(CO)2 (2a–c), were isolated and fully characterized by NMR, IR, CV, UV–vis-NIR absorption, and X-ray crystallographic analyses. Each isomer was stable at ambient conditions and isomerization among 2a–c occurred at elevated temperature both in solution and in a solid state, through the intramolecular rotational pathways. Electronic structures of 2a–c were analyzed in detail by DFT study to reveal appreciable differences in the interaction between the NFTPp ligand and the Ru–Cl moiety.