Metastable Linkage Isomerism in Ni(Et4dien)(NO2)2: A Combined Thermal and Photocrystallographic Structural Investigation of a Nitro/Nitrito Interconversion

One way or another: The N‐bound NO2 group in Ni(Et4dien)(η2‐O,ON)(η1‐NO2) (see structure Ni turquoise, N blue, O red) has been shown to undergo reversible conversion into the O‐bound nitrito linkage isomer under both thermal and photoactivation of a single crystal. Et4dien=N,N,N′,N′‐tetraethyldiethylenetriamine.