Novel mixed-ligand rhodium(II) paddle-wheel complexes incorporating tethered axial thioether ligands have been synthesized and characterized. The thioether moiety is essential for high yields and the suppression of byproducts in cyclopropanation reactions using an electron-deficient diazoacetate. Crystal structures, UV-vis analysis, and cyclic voltammetry experiments shed light on the catalytic performance of the complexes.