Jump to main content
Jump to site search

Issue 40, 2010
Previous Article Next Article

Preparation and characterisation of divalent hard and soft metal (M = Ca, Co, Cu, Zn, Cd, Hg and Pb) complexes of 1,10-dithia-18-crown-6: structural versatility

Author affiliations

Abstract

A range of divalent metal complexes (1–10) of 1,10-dithia-18-crown-6 (L) were synthesised in benzonitrile and structurally characterised. In particular cases (Cd, Hg and Pb), the anion effect on the resulting structures was investigated. The calcium(II) complex [Ca(L)(ClO4)2] (1) for L, adopting an ‘egg-in-nest’ conformation was isolated. The calcium centre is six-coordinate with a distorted trigonal prismatic geometry, being bound to four oxygens of L and two perchlorato ligands. When Co(ClO4)2·6H2O was employed, the purple complex [Co(L)(H2O)3]2(ClO4)4 (2a) with a distorted octahedral geometry was obtained as a kinetic product, which then transformed to the solvato-complex [Co(C6H5CN)4(H2O)2](ClO4)2 (2b, yellow) as a thermodynamic product. In contrast to 2a, the reaction with Cu(ClO4)2·6H2O afforded an anion-coordinated complex [Cu(L)(ClO4)2]·2C6H5CN (3). In 3, the copper centre is also six-coordinate, being bound to two oxygens and two sulfurs from L, in which the distorted octahedral geometry is completed by two perchlorato ligands. Reaction of L with Zn(ClO4)2·6H2O yielded the mononuclear species [Zn(L)(H2O)3]2(ClO4)4 (4), in which the octahedral geometry of the zinc(II) is almost same as that of 2a. L reacts with CdX2 (X = ClO4 and NO3) to yield [Cd(L)(ClO4)2] (5) and [Cd(L)(NO3)]2[Cd(NO3)4] (6), respectively. In perchlorato-complex 5, all six donors in L participate in the coordination sphere, in which the eight-coordinated ‘tight and bent’ conformation is completed by two perchlorate ions, adopting a dicapped trigonal prismatic geometry. Interestingly, the nitrato-complex 6 features three separated units of formula [Cd(L)(NO3)]2[Cd(NO3)4]: two macrocyclic complex cation units and one cadmium quadru-nitrato complex anion unit. In the reaction with HgX2 (X = ClO4 and NO3), L afforded an unusual triple-decker type dinuclear complex [Hg2(L)3](ClO4)4 (7) with 3 : 2 (L : M) stoichiometry and a 1 : 1 complex [Hg(L)(NO3)2]·2H2O (8) with an eight-coordinate mercury centre, adopting a distorted hexagonal bipyramidal geometry. L reacts with PbX2 (X = ClO4 and NO3) to yield [Pb(L)(ClO4)2] (9) and [Pb(L)(NO3)2] (10). In 9, the lead(II) is six-coordinate, being bound to four oxygens, in which the distorted octahedral geometry is completed by two perchlorato ligands. In 10, the lead(II) coordinates to four oxygens together with two bidentate nitrato-ligands to yield an overall metal coordination geometry of eight, adopting the ‘egg-in-nest’ conformation again.

Graphical abstract: Preparation and characterisation of divalent hard and soft metal (M = Ca, Co, Cu, Zn, Cd, Hg and Pb) complexes of 1,10-dithia-18-crown-6: structural versatility

Back to tab navigation

Supplementary files

Publication details

The article was received on 22 Jun 2010, accepted on 02 Jul 2010 and first published on 07 Sep 2010


Article type: Paper
DOI: 10.1039/C0DT00696C
Dalton Trans., 2010,39, 9696-9704

  •   Request permissions

    Preparation and characterisation of divalent hard and soft metal (M = Ca, Co, Cu, Zn, Cd, Hg and Pb) complexes of 1,10-dithia-18-crown-6: structural versatility

    I. Park, K. Park and S. S. Lee, Dalton Trans., 2010, 39, 9696
    DOI: 10.1039/C0DT00696C

Search articles by author

Spotlight

Advertisements