Mononickel(II), dimercury(II), and 1-D polymeric silver(I) complexes with a ditopic 18-membered N2O2S2-macrocycle.

A ditopic 18-membered N 2 O 2 S 2 -macrocycle ( L ) incorporating hard (NO 2 ) and soft (NS 2 ) binding sites in each side was employed and its three complexes ( 1 – 3 ) exhibiting different stoichiometries, geometries, and topologies have been prepared and structurally characterized. First, nickel(II) nitrate hexahydrate reacts with L to give a mononuclear complex [Ni( L )](NO 3 ) 2 ·2H 2 O ( 1 ) in which the metal center locates inside the macrocyclic cavity adopting a hexa-coordinated octahedral geometry shielded by the strongly bound macrocycle from the anion and solvent. While, silver(I) tetrafluoroborate afforded a one-dimensional coordination polymer {[Ag( L )]BF 4 } n ( 2 ) with an L -Ag- L -Ag pattern. In 2 , the silver(I) center is penta-coordinate with NO donors from one L and NS 2 donors from an adjacent L to form a sandwich-type adopting a distorted trigonal bipyramidal geometry. Mercury(II) chloride yielded a dinuclear complex [Hg 2 ( L )Cl 4 ] ( 3 ) in which two mercury(II) ions locate opposite side of L in a chair form. Each mercury(II) center in 3 is penta-coordinate, being bound to one pyridine N atom, two O(S) donors in the compositional disorder, and two chloride ions adopting a distorted square-pyramidal geometry. The comparative NMR studies show the preferential binding affinity of silver(I) over potassium(I) toward L . [ABSTRACT FROM AUTHOR]