Synthesis of functionalized porphyrins for application as soft materials

Abstract

The series of functionalized porphyrins was designed and synthesized by varying para-substituents on meso-position of porphyrin ring as ether, ester, and urea with three different long alkyl chains (3-5, 7-9, 11). Afterwards, metalation of porphyrin derivatives by some 3d metals to serve as soft materials, liquid crystal, and axial ligands were introduced to provide spin-crossover property.

Each series of functionalized porphyrin derivatives with three different chain lengths (3-5, 7-9, 11) and their Co(II) (3-5a,7-9a), Ni(II) (3-5b,7-9b), and Fe (III) (3-5c,7-9c) complexes were characterized by spectroscopic techniques consisting of NMR, IR, UV-visible and MS. The desired compounds were studied their mesomorphic and magnetic behaviors by DSC and SQUID, respectively.

Most metalloporphyrins such as Ni(II), Co(II) and Fe(III) complexes (4-5c, 7-9a,b,c) exhibited liquid crystalline property whereas some axial-ligand complexes (7-9a-imidazole, 5c-imidazole) behaved as paramagnetic soft materials.