Tripodal Bis(imidazole) Thioether Copper(I) Complexes:  Mimics of the Cu(B) Site of Hydroxylase Enzymes

Tripodal bis(imidazole) thioether ligands and the corresponding copper(I) complexes [(BIMT-OR)Cu(L)]PF6 [L = CH3CN (2), CO (3); R = H (a), CH3 (b)] have been prepared as models for the Cu(B) site of copper hydroxylase enzymes. The IR (CO) values of 3a and 3b (L = CO) are comparable to those of the carbonylated enzymes. The reaction of 2a with O2 gives dinuclear complex 4 with bridging BIMT-O ligands and oxidized -SMe groups, whereas oxygenation of 2b affords [(BIMT-OMe)2Cu2O(H)2](CF3SO3)2 (5) and Cu(BIMT-OMe)(DMF)2](PF6)2 (6).