Self-ordering of metallogrid complexes via directed hydrogen-bonding.
Fiche publication
Date publication
décembre 2012
Auteurs
Membres identifiés du Cancéropôle Est :
Pr LEHN Jean-Marie
Tous les auteurs :
Stefankiewicz AR, Rogez G, Harrowfield J, Sobolev AN, Madalan A, Huuskonen J, Rissanen K, Lehn JM
Lien Pubmed
Résumé
Reaction of imidazole aldehydes with dihydrazino derivatives of 2-phenylpyrimidine provides a family of bis(acylhydrazone) ligands which form [2 x 2] metallogrid complexes with transition metal ions including Fe(II), Co(II), Cu(II) and Zn(II). The free ligands show H-bonding interactions, both donor and acceptor, largely involving the imidazole units, while binding of the metal ions occupies all the acceptor sites and leaves only the pyrrolic-NH site as an H-bond donor, although its deprotonation by a strong base can regenerate an acceptor. These H-bonding interactions have been studied by (1)H NMR spectroscopy in solution and in the solid state by means of several crystal structure determinations. The Fe(II) grids appear to be exclusively high-spin species over a wide temperature range in solution. In the solid state various forms of spin-crossover behaviour can be observed between 1.8 and 300 K, which has been rationalised in terms of the varied forms of hydrogen-bonding possible in the crystalline state.
Référence
Dalton Trans. 2012 Dec 7;41(45):13848-55