The importance of questioning scientific assumptions: some lessons from f element chemistry.

As scientists, we know that we should constantly question the assumptions upon which our research is based. We also know that we do not do this often enough. The recent results in f element chemistry described here should serve to remind us not to take the traditional boundaries of any area of chemistry for granted including topics as fundamental as redox chemistry and bond-length generalizations. New ways of doing reductive chemistry in the f element area as well as the synthesis of "long bond organometallics" that have unconventional bond distances and reactivity demonstrate how the "rules" in this area, thought to be true for decades, have been recently overturned. The synthetic chemistry that made these advances possible has generated additional unexpected opportunities in f element chemistry that are also described here. Overall, these results should stimulate researchers in all areas to challenge their assumptions.