Controlled Access to Mixed-Metal Pyridazine-Linked Cryptates

• Published in: European journal of inorganic chemistry 2004-06, Vol.2004 (12), p.2570-2584
• Main Authors: Ronson, Tanya K., Nelson, Jane, Jameson, Geoffrey B., Jeffery, John C., Brooker, Sally
• Format: Article
• Language: English
• Subjects: Cryptates; Cyclic voltammetry; Heterometallic complexes; N ligands; Structure elucidation
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.200400068

The pyridazine‐linked cryptand L [formed by the 3+2 condensation of 3,6‐diformylpyridazine with tris(2‐aminoethyl)amine (tren)] has been used to generate a series of heterodinuclear cryptates by a one‐pot two‐step method. The cryptates [MnIICuIL](ClO4)2(BF4), [FeIICuIL](BF4)3·CH3CN and [NiIICuIL](BF4)3·H2O have been structurally characterized, with elemental analyses and mass spectroscopic data providing further evidence of their heterodinuclear nature. The synthesis, structures and characterisation of the corresponding mononuclear cryptates [MIIL](X)2 (M = Mn, Fe, Ni, X = BF4− or ClO4−) are also reported, along with the synthesis and characterisation of the homodinuclear dizinc(II) and disodium(I) cryptates, [Zn2L](ClO4)4 and [Na2L](CF3SO3)2. Electrochemical studies on the heterodinuclear cryptates in CH3CN indicate that the presence of the divalent cation influences the electrochemical potential and reversibility of the CuI → CuII oxidation with the redox potential of the CuI/CuII couple being inversely correlated with the distance between the two metal ions in the solid state as determined by X‐ray crystallography. The previously synthesised [CoIICuIL](BF4)3 is an exception to this trend, probably due to oxidation of the CoII ion prior to that of the CuI ion. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)