On the role played by the chirality of ligands on the aggregation of heterometallic CuII -HgII complexes.

Copper(II) complexes constructed from enantiopure Schiff-base ligands derived from o-vanillin and methionine or from their racemic mixture have been employed as metalloligands towards mercury(II) ions. The nature of the heterometallic CuII -HgII complexes (coordination polymers or oligonucler species), resulted from the reactions of the copper(II) complexes with HgCl2 or HgI2 , is different. The enantiopure metalloligands lead to chiral coordination polymers, 1∞ [{Cu(R-/S-valmet)(H2 O)}2 HgCl2 ]·5H2 O·CH3 OH and 2∞ [{Cu2 (R-/S-valmet)2 (µ-H2 O)(H2 O)2 }HgI2 ]·4H2 O. The reaction of the racemic mixture of the metalloligands with HgX2 affords discrete complexes: [{Cu(R,S-valmet)(H2 O)2 }2 HgCl2 ]·2H2 O and [{Cu(R,S-valmet)(H2 O)(CH3 OH)}2 Hg2 I4 ].