Journal of the American Chemical Society, Vol.118, No.43, 10487-10493, 1996
Gemini-Porphyrazines - The Synthesis and Characterization of Metal-Capped Cis-Porphyrazine and Trans-Porphyrazine Tetrathiolates
Peripherally-functionalized porphyrazines of the form M[pz(A(n):BS4-n)] (inset 1), where A and B symbolize functional moieties (e.g., a-d in Table 1) fused directly to the beta-positions of the pyrroles, have the potential to serve in a wide range of applications. Previously, we reported the synthesis of porphyrazinedi- and octathiolate ligands, M[pz(b(3):c(1))] and M[pz(c(4))], respectively, where b is a fused benzo ring and c represents two thiolates fused at the beta-pyrrole positions to form a dithiolene capable of the peripheral chelation of a metal ion. We describe here a general strategy that solves the more difficult problem of preparing and isolating the porphyrazinetetra- and hexathioethers and the porphyrazinetetra- and hexathiolates, with the focus being the trinuclear metal complexes of the trans- and cis-porphyrazinetetrathiolate isomers (trans- and cis-M[pz(b(2):d(2))]), denoted as gemini porphyrazines. Spectroscopic and electrochemical studies reveal that the physical properties of the cis- and trans-tetrathioether porphyrazines exhibit intriguing differences associated with their distinct molecular symmetries. These functionalized macrocycles have been used to prepare the trans- and cis-gemini porphyrazines 14 and 16, the two isomeric porphyrazinetetrathiolate macrocycles that are peripherally-metalated with two bis(triethylphosphine)platinum(II) moieties. The X-ray structure of the trans isomer, 14, is presented; it is the first structure of a porphyrazine or phthalocyanine having a trans-type substitution pattern.
Keywords:X-RAY STRUCTURE;SUBSTITUTED PHTHALOCYANINES;PLATINUM(II) COMPLEXES;STAR-PORPHYRAZINES;CRYSTAL-STRUCTURE;D(2H) SYMMETRY;SPECTROSCOPY;LIGAND;DITHIOLATE;CHARGE