Two pseudohalide-bridged Cu(II) complexes bearing the anthracene moiety: Synthesis, crystal structures and catecholase-like activity

Abstract In two binuclear complexes of formula [Cu 2 (AnthenMe 2 ) 2 (μ 1,3 -SCN) 2 (NCS) 2 ] ( 1 ) and [Cu 2 (AnthenMe 2 ) 2 (μ 1,1 -N 3 ) 2 (N 3 ) 2 ] ( 2 ), where AnthenMe 2 is the bidentate N , N -donor Schiff base formed by anthracene-9-aldehyde and N , N -dimethylethylenediamine, each Cu(II) center adopts a square pyramidal geometry with N 4 S and N 5 coordination environments for 1 and 2 , respectively. In spite of the very different Cu⋯Cu separations in these two complexes (5.141 A in 1 and 3.4744 A in 2 ), the molecules show very similar catalytic efficiency for the aerial oxidation of 3,5-ditertiarybutyl catechol (DTBCH 2 ) to the corresponding quinone (DTBQ), probably because similar mononuclear complexes are involved in the catalytic reaction in both the cases. The k cat and k cat / K M values of 1.53(0.20) × 10 4  h −1 and 5.71(0.15) × 10 7  M −1  h −1 for 1 and 1.56(0.12) × 10 4  h −1 and 5.61(0.12) × 10 7  M −1  h −1 for 2 are comparable to the best values reported in the literature for Cu(II) model complexes of catecholase.