A single carbon atom controls the geometry and reactivity of Co II (N 2 S 2 ) complexes.

Three- vs . two-carbon N-to-N connectors give rise to monomeric, tetrahedral N 2 S 2 Co(II) ( μ eff = 4.24 BM) or dimeric [(N 2 S 2 )Co(II)] 2 (diamagnetic) complexes, respectively. Differences in the derivative products of the Lewis acid receivers, W 0 (CO) 3 and W 0 (CO) 4 , illustrate nucleophilicity of the thiolate sulfur lone pairs in each case, as well as their structural control.