An important reaction is the acid/base equilibrium, yielding transition metal nitrite complexes:
:[LMNO] + 2OH  LMNO + HO
This equilibrium serves to confirm that the linear nitrosyl ligand is, formally, NO, with nitrogen in the oxidation state +3
:NO + 2 OH  NO + HO
Since nitrogen is more electronegative than carbon, metal-nitrosyl complexes tend to be more electrophilic than related metal carbonyl complexes. Nucleophiles often add to the nitrogen. The nitrogen atom in bent metal nitrosyls is basic, thus can be oxidized, alkylated, and protonated, e.g.:
:(PhP)(CO)ClOsNO + HCl → (PhP)(CO)ClOsN(H)O
In rare cases, NO is cleaved by metal centers:
: CpNbMe + NO → Cp(Me)Nb(O)NMe
: 2 Cp(Me)Nb(O)NMe → 2 CpNb(O)Me + ½MeN=NMe