The use of imidazolium-2-dithiocarboxylates in the formation of gold(I) complexes and gold nanoparticles

Saira Naeem; Lionel Delaude; Andrew J P White; James D E T Wilton-Ely

doi:10.1021/ic9021504

The use of imidazolium-2-dithiocarboxylates in the formation of gold(I) complexes and gold nanoparticles

Inorg Chem. 2010 Feb 15;49(4):1784-93. doi: 10.1021/ic9021504.

Authors

Saira Naeem¹, Lionel Delaude, Andrew J P White, James D E T Wilton-Ely

Affiliation

¹ Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.

PMID: 20088565
DOI: 10.1021/ic9021504

Abstract

The imidazolium-2-dithiocarboxylate ligands IPr.CS(2), IMes.CS(2), and IDip.CS(2) react with [AuCl(PPh(3))] to yield [(Ph(3)P)Au(S(2)C.IPr)](+), [(Ph(3)P)Au(S(2)C.IMes)](+), and [(Ph(3)P)Au(S(2)C.IDip)](+), respectively. The compounds [(L)Au(S(2)C.IMes)](+) are prepared from the reaction of IMes.CS(2) with [AuCl(L)] (L = PMe(3), PCy(3), CN(t)Bu). The carbene-containing precursor [(IDip)AuCl] reacts with IPr.CS(2) and IMes.CS(2) to afford the complexes [(IDip)Au(S(2)C.IPr)](+) and [(IDip)Au(S(2)C.IMes)](+) with two carbene units, one bound to the metal center and the other to the dithiocarboxylate unit. Treatment of the diphosphine-gold complex [(dppm)(AuCl)(2)] with 1 equiv of IMes.CS(2) yields [(dppm)Au(2)(S(2)C.IMes)](2+), while the reaction of [L(2)(AuCl)(2)] (L(2) = dppb, dppf) with 2 equiv of IMes.CS(2) results in [(L(2)){Au(S(2)C.IMes)}(2)](2+). The homoleptic complexes [Au(S(2)C.IPr)(2)](2+), [Au(S(2)C.IMes)(2)](2+), and [Au(S(2)C.IDip)(2)](2+) are obtained from the reaction of [AuCl(tht)] with 2 equiv of the appropriate imidazolium-2-dithiocarboxylate ligand. The compounds [(Ph(3)P)Au(S(2)C.NHC)](+) (NHC = IMes, IDip) and [(IDip)Au(S(2)C.NHC)](+) (NHC = IPr, IMes) are characterized crystallographically. The IMes.CS(2) ligand is also used to prepare functionalized gold nanoparticles with diameters of 11.5 (+/-1.2) and 2.6 (+/-0.3) nm.