Covalently Linked meso-BODIPYnyl Dithiahomoporphyrins: Synthesis and Properties

A series of novel covalently linked meso-BODIPYnyl dithiahomoporphyrins was synthesized by treating readily available tetrapyrrane and appropriate formyl BODIPY derivatives in the presence of catalytic amount of BF3OEt2 in CH2Cl2 followed by oxidation using DDQ. The meso-BODIPYnyl dithiahomoporphyrins were characterized by HR-MS, 1D, 2D NMR and absorption spectroscopy, cyclic voltammetry and DFT studies. The spectral and electrochemical studies suggest that the BODIPY and homoporphyrin units in meso-BODIPYnyl dithiahomoporphyrins retain their original identities. The compounds were non-fluorescent due to intramolecular charge transfer from dithiahomoporphyrin moiety to a respective BODIPY unit in meso-BODIPYnyl dithiahomoporphyrins. The DFT studies supported the intramolecular charge transfer between the two chromophores in meso-BODIPYnyl dithiahomoporphyrins