Non-innocent ligand

In chemistry, a (redox) non-innocent ligand is a ligand in a metal complex where the oxidation state is not clear. Typically, complexes containing non-innocent ligands are redox active at mild potentials. The concept assumes that redox reactions in metal complexes are either metal or ligand localized, which is a simplification, albeit a useful one.[1]

C.K. Jørgensen first described ligands as "innocent" and "suspect": "Ligands are innocent when they allow oxidation states of the central atoms to be defined. The simplest case of a suspect ligand is NO..."[2]

  1. ^ Ganguly, Sumit; Ghosh, Abhik (2019-07-16). "Seven Clues to Ligand Noninnocence: The Metallocorrole Paradigm". Accounts of Chemical Research. 52 (7): 2003–2014. doi:10.1021/acs.accounts.9b00115. ISSN 0001-4842. PMID 31243969. S2CID 195695184.
  2. ^ Jørgensen CK (1966). "Differences between the four halide ligands, and discussion remarks on trigonal-bipyramidal complexes, on oxidation states, and on diagonal elements of one-electron energy". Coordination Chemistry Reviews. 1 (1–2): 164–178. doi:10.1016/S0010-8545(00)80170-8.