Synthesis of μ‐Cyano(2,3‐naphthalocyaninato)iron(III) and Comparison to μ‐Cyano(phthalocyaninato)iron(III)

Potassium dicyano(2,3‐naphthalocyaninato)ferrate(III), K[2,3‐NcFe(CN) 2 ] ( 2 ), reacts in water with elimination of KCN to form μ‐cyano(2,3‐naphthalocyaninato)iron(III), [2,3‐NcFe(CN)] n ( 4a ). Dichloro(2,3‐naphthalocyaninato)iron(III), 2,3‐NcFeCl 2 ( 3 ), reacts with KCN to yield also [2,3‐NcFe(CN)] n ( 4b ). Both compounds 4a and 4b show similar IR spectra with a typical blue‐shifted CN valence frequency caused by a bridging function of CN ‐ . Compounds 4a and 4b also show almost identical 57 Fe‐Mössbauer spectra which, however, might be interpreted with a Fe(+II) oxidation state of the iron. The measured magnetic moment of 4 however clearly proves the expected oxidation state +III of the iron in [2,3‐NcFe(CN)] n ( 4 ). Compounds 4a and 4b both exhibit good semiconducting properties (σ RT ∼ 10 –3 S/cm) without additional external oxidative doping. The property is quite similar to that of the known μ‐cyano(phthalocyaninato)iron [PcFe(CN)] n (σ RT ∼ 10 ‐2 S/cm).