N. Bréfuel, C. Lepetit, S. Shova
Oct 25, 2005
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0
Influential Citations
33
Citations
Journal
Inorganic Chemistry
Abstract
The condensation reaction between 2-pyridinecarboxaldehyde and diethylenetriamine, 3-[(2-aminoethyl)amino]propylamine, and 3,3‘-iminobis(propylamine) in a 2:1 molar ratio yields ligands that may be isolated exclusively in the dissymmetric (cyclic) isomeric forms LA, LB/LB*, and LC. The template effect of a metal center (FeII, NiII,and ZnII) results in the ring opening of LC including one hexahydropyrimidine ring and one (long) propylene bridge. The resulting symmetric bis-Schiff base isomeric form LC‘ is stabilized through pentacoordination, yielding [FeIILC‘(NCS)](NCS) (3), [NiIILC‘(NCS)](NCS) (6), and [ZnIILC‘(NCS)](NCS) (9). The same metal centers are too bulky to exert a template effect on LA including one imidazolidine ring and one (short) ethylene bridge. LA acts as a tetradentate ligand yielding [FeIILA(NCS)2] (1), [NiIILA(NCS)2] (4), and [ZnIILA(NCS)2] (7). The template effect of the metal center is selective toward the ligand LB/LB* including a hexahydropyrimidine (imidazolidine) ring and the sho...