Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 4, 1983
Previous Article Next Article

Crown ethers as second-sphere ligands. The interactions of transition-metal ammines with 18-crown-6 and dibenzo-18-crown-6

Abstract

Neutral and cationic transition-metal ammines interact with crown ethers in aqueous and non-aqueous solution via(N–H ⋯ O) hydrogen-bond formation to give discrete or polymeric adducts which are readily isolated by crystallisation. Dibenzo-18-crown-6 generally yields discrete 1 : 1 (metal complex : crown) adducts in which only one face of the macrocycle interacts with an ammine ligand, whereas 18-crown-6 often binds two such ligands, one to each face of the crown ether. The resulting adducts are then either polymeric or of 2 : 1 (metal complex : crown) stoicheiometry. Ammines which yield isolable adducts include [W(CO)5(NH3)], trans-[PtCl2(PMe3)(NH3)], trans-[PtCl2(NH3)2], [Co(NH3)6][PF6]3, [Cu(NH3)4(H2O)][PF6]2, and [Pt(H2NCH2CH2NH2)2][PF6]2. Such adduct formation provides the basis for a novel method of separating different transition metals; for example, 18-crown-6 selectively precipitates the copper(II) complex (as a polymeric 1:1 adduct) in the presence of an equimolar amount of the cobalt(III) ammine.

Back to tab navigation

Article information


J. Chem. Soc., Dalton Trans., 1983, 607-613
Article type
Paper

Crown ethers as second-sphere ligands. The interactions of transition-metal ammines with 18-crown-6 and dibenzo-18-crown-6

H. M. Colquhoun, D. F. Lewis, J. F. Stoddart and D. J. Williams, J. Chem. Soc., Dalton Trans., 1983, 607
DOI: 10.1039/DT9830000607

Search articles by author

Spotlight

Advertisements