Electrochemical interactions in binuclear molybdenum and tungsten nitrosyl complexes incorporating saturated n-alkanediolate bridging ligands. Crystal structures of [Mo(NO)(TpMe2)I{O(CH2)2OCOCH3}] and [W(NO)(TpMe2)I2] · 0.5I2 · 0.5C6H5CH3

The electrochemical interactions, ΔE1/2, in bimetallic Mo and W complexes with saturated bridges being large for the complex with a C2 bridge (310 mV, Mo⋯Mo distance > 6 Å) decrease by ca. 100 mV per CH2 group with increased length for C2 to C4 bridges and become undetectable for complexes with bridges longer than C4. The substitution of fluorine into the C5 bridge causes the effect to become measurable due to easier polarisation of the σ-bond framework.