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

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 Co2Pc2 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 [(CoIPc−2)2]2−/[(CoIPc−3)2]4− (I), (CoIIPc−2)2/[(CoIPc−2)2]2− (II) and one oxidation process assigned to [(CoIIIPc−2)2]2+/CoIIPc−2)2 (III). The ball-type complexes are much easier to oxidize and more difficult to reduce than the corresponding monomers 8 and 9.

Graphical abstractBall-type dinuclear Co2Pc2 substituted at the non-peripheral (10) and peripheral (11) positions with 1,1′-binaphtol exhibited two (two electron) reduction processes and one (two electron) oxidation processes.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► Mononuclear and ball-type cobalt phthalocyanine (CoPc) substituted at the non-peripheral and peripheral positions with 1,1′-binaphthyl-8,8′-diol. ► The ball-type complexes showed no significant intermolecular interaction between the Pc rings. ► The ball-type complexes exhibited one step two-electron processes electrochemically. ► The ball-type complexes are much easier to oxidize and more difficult to reduce than the corresponding monomers.