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 nu(CO) values of 3a and 3b (L = CO) are comparable to those of the carbonylated enzymes. The reaction of 2a with O-2 gives dinuclear complex 4 with bridging BIMT-O ligands and oxidized-SMe groups, whereas oxygenation of 2b affords [(BIMT-OMe)(2)Cu2O(H)(2)](CF3SO3)(2) (5) and Cu(BIMT-OMe)(DMF)(2)](PF6)(2) (6).