Structural and metallo selectivity in the assembly of [2 x 2] grid-type metallosupramolecular species: mechanisms and kinetic control.

Fiche publication


Date publication

décembre 2011

Auteurs

Membres identifiés du Cancéropôle Est :
Pr LEHN Jean-Marie


Tous les auteurs :
Stefankiewicz AR, Harrowfield J, Madalan A, Rissanen K, Sobolev AN, Lehn JM

Résumé

An unsymmetrical bis(tridentate) ligand LH in which one binding site can be readily deprotonated forms a kinetically inert [Co(III)L(2)](+) complex which can be used as a "corner" species for the "Coupe du Roi" assembly of trans,trans-[Co(2)M(2)L(4)](6+) metallogrids (M = Fe(II), Co(II), Cu(II), Zn(II)). In the mixed Co(III)/Co(II) species, the oxidation states appear to be localised. In solution, the ligand LH forms octacationic, homometallic [2 x 2] grids with the individual labile metal ions Fe(II), Co(II), Cu(II), Zn(II), seemingly as mixtures of all possible isomers arising from the unsymmetrical nature of the ligand. In the solid state, however, [Zn(4)L(4)](CF(3)SO(3))(8).4CH(3)CN crystallises as a single species where the cation has S(4) symmetry. This stereoselectivity in the crystalline lattice is associated with interactions between the cation and triflate anions which can again be analysed in terms of the Coupe du Roi concept.

Référence

Dalton Trans. 2011 Dec 7;40(45):12320-32