Conversely, most arylnitrenium ions are ground state singlets. Certain substituted arylnitrenium ions can be ground state triplets, however. Nitrenium ions can have microsecond or longer lifetimes in water.
Most arylnitrenium ions are found in the ground state as singlets, while some substituted arylnitrenium ions can exist in the ground state as triplets. Nitrenium ions typically have lifetimes of microseconds or even longer when they are dissolved in water.