Sterically induced reduction

Sterically induced reductions commonly involve metals found in the lanthanoid and actinoid series.

In these cases, adjusting the size of the metal (which is commonly and easily done for the trivalent lanthanide compounds) may fine tune the nature of a specific reaction, which should produce desired and clean products.

One drawback to this notion is that Sm(II) is uniquely stable compared to other divalent lanthanides, where the other metals in the series tend to exist freely in the trivalent state.

However, steric factors must also be considered on the reactivity of the Sm(III) complex as less crowded structures do not have any reductive activity.

[1] Sm is a typical and well studied metal due to its unusual stability in a divalent and trivalent state.