(a) The structures of the Mo(IV) and Mo(VI)=O sites of DMSO reductase (left and right, respectively), (b) the Mo(IV) and Mo(VI)=O bis-dithiolene complexes in this study (left and right, respectively), and (c) the Mo tris-dithiolene complexes in this study. Note that z-axis lies along the Mo-O and Mo=O bonds for the Mo(IV) and Mo(VI)=O bis-dithiolenes, respectively, while for the Mo tris-dithiolene complexes, the z-axis lies along the C3 rotation axis.