A high-five for praseodymium

The lanthanides comprise a series of 15 elements that have applications in many modern technologies, including magnetic materials and optics. Their chemistry has been traditionally dominated by the +II and +III oxidation states; higher oxidation states, except in the case of cerium, have long been deemed unreachable. Now, an example of a stable praseodymium complex in the formal oxidation state +V has been observed.