New bis-o-semiquinonato cobalt complexes with 1,10-phenanthroline ligands

Complex (1,10-phen)Co(4-OMe-3,6-DBSQ)2 undergo reversible thermally driven redox-isomeric transformation which is accompanied by phase transition. Methoxy substituent in quinonato ligand does not affect the equilibrium position comparing to (1,10-phen)Co(3,6-DBSQ)2 described earlier. At the same time methyl groups in (2,9-Me2-1,10-phen)Co(3,6-DBSQ)2 prevent bonds shortening necessary for redox-isomeric transformation.