Syntheses, electrochemical and spectroelectrochemical properties of novel ball-type and mononuclear Co(II) phthalocyanines substituted at the peripheral and non-peripheral positions with binaphthol groups

Abstract

Mononuclear cobalt phthalocyanine (CoPc) substituted at the non-peripheral 8 and peripheral positions 9 with 1,1′-binaphthyl-8,8′-diol and ball-type dinuclear Co 2Pc 2 substituted at the non-peripheral 10 and peripheral 11 positions with the same substituent are reported. The complexes with 1,1′-binaphthol-bridges were prepared from the corresponding phthalonitriles 4– 7. The effects of the position of substituent on spectral, electrochemical and spectroelectrochemical properties of these complexes were also explored. The mononuclear complexes 8 and 9 exhibited one metal reduction, one ring reduction and one ring oxidation. The redox properties of the ball-type complexes 10 and 11 exhibited two reduction processes assigned to [(Co IPc −2) 2] 2−/[(Co IPc −3) 2] 4− ( I), (Co IIPc −2) 2/[(Co IPc −2) 2] 2− ( II) and one oxidation process assigned to [(Co IIIPc −2) 2] 2+/Co IIPc −2) 2 ( III). The ball-type complexes are much easier to oxidize and more difficult to reduce than the corresponding monomers 8 and 9.