Gold(I) complexes bearing mixed-donor ligands derived from N-heterocyclic carbenes

in Dalton Transactions (2011), 40(25), 6645-6658

The new 2-phenylthiocarbamoyl-1,3-dimesitylimidazolium inner salt (IMes•CSNPh) reacts with [AuCl(L)] in the presence of NH4PF6 to yield [(L)Au(SCNPh•IMes)]+ (L = PMe3, PPh3, PCy3, CNBut). The carbene ... [more ▼]

The new 2-phenylthiocarbamoyl-1,3-dimesitylimidazolium inner salt (IMes•CSNPh) reacts with [AuCl(L)] in the presence of NH4PF6 to yield [(L)Au(SCNPh•IMes)]+ (L = PMe3, PPh3, PCy3, CNBut). The carbene-containing precursor [(IDip)AuCl] reacts with IMes•CSNPh under the same conditions to afford the complex [(IDip)Au(SCNPh•IMes)] + (IDip = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene). Treatment of the diphosphine complex [(dppm)(AuCl)2] with one equivalent of IMes•CSNPh yields the digold metallacycle, [(dppm)Au 2(SCNPh•IMes)]2+, while reaction of [L 2(AuCl)2] with two equivalents of IMes•CSNPh results in [(L2){Au(SCNPh•IMes)}2]2+ (L2 = dppb, dppf, or dppa; dppb = 1,4-bis(diphenylphosphino)butane, dppf = 1,1'-bis(diphenylphosphino)ferrocene, dppa = 1,4- bis(diphenylphosphino)acetylene). The homoleptic complex [Au(SCNPh•IMes) 2]+ is formed on reaction of [AuCl(tht)] (tht = tetrahydrothiophene) with two equivalents of the imidazolium-2- phenylthiocarbamoyl ligand. This product reacts with AgOTf to yield the mixed metal compound [AuAg(SCNPh•IMes)2]2+. Over time, the unusual trimetallic complex [Au(AgOTf)2(SCNPh•IMes) 2]+ is formed. The sulfur-oxygen mixed-donor ligands IMes•COS and SIMes•COS (SIMes = 1,3-bis(2,4,6-trimethylphenyl) imidazolin-2-ylidene) were used to prepare [(L)Au(SOC•IMes)]+ and [(L)Au(SOC•SIMes)]+ from [(L)AuCl] (L = PPh3, CNtBu). The bimetallic examples [(dppf){Au(SOC•IMes)} 2]2+ and [(dppf){Au(SOC•SIMes)}2] 2+ were synthesized from the reaction of [(dppf)(AuCl)2] with the appropriate ligand. Reaction of [(tht)AuCl] with one equivalent of IMes•COS or SIMes•COS yields [Au(SOC•IMes) 2]+ and [Au(SOC•SIMes)2]+, respectively. The compounds [(Ph3P)Au(SCNPh•IMes)]PF 6, [(Cy3P)Au(SCNPh•IMes)]PF6 and [Au(AgOTf)2(SCNPh•IMes)2]OTf were characterized crystallographically. [less ▲]

The Use of Imidazolium-2-dithiocarboxylates in the Formation of Gold(l) Complexes and Gold Nanoparticles

in Inorganic Chemistry (2010), 49(4), 1784-1793

The imidazolium-2-dithiocarboxylate ligands IPr.CS2, Mes.CS2, and IDip.CS2 react with [AuCl(PPh3)] to yield [(Ph3P)Au(S2C.IPr))(+), [(Ph3P)Au(S2C.IMes)](+), and [(Ph3P)Au(S2C-IDip)](+), respectively. The ... [more ▼]

The imidazolium-2-dithiocarboxylate ligands IPr.CS2, Mes.CS2, and IDip.CS2 react with [AuCl(PPh3)] to yield [(Ph3P)Au(S2C.IPr))(+), [(Ph3P)Au(S2C.IMes)](+), and [(Ph3P)Au(S2C-IDip)](+), respectively. The compounds [(L)Au(S2C-IMes)](+) are prepared from the reaction of IMes.CS2 with [AuCl(L) (L = PMe3, PCy3, (CNBu)-Bu-t). The carbene-containing precursor [(IDip)AuCl] reacts with IPr.CS2 and IMes.CS2 to afford the complexes [(IDip)Au(S2C.IPr)](+) and [(IDip)Au(S2C.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.CS2 yields [(dppm)Au-2(S2C.IMeS)](2+), while the reaction of [L-2(AuCl)(2)] (L-2 = dppb, dppf) with 2 equiv of IMes.CS2 results in [(L-2){Au(S2C.IMes)}(2)](2+). The homoleptic complexes [Au(S2C.IPr)(2)](2+), [Au(S2C.IMes)(2)](2+), and [Au(S2C.IDiP)(2)](2+) are obtained from the reaction of [AuCl(tht)] with 2 equiv of the appropriate imidazolium-2-dithiocarboxylate ligand. The compounds [(Ph3P)Au(S2C.NHC)](+) (NHC = IMes, IDip) and [(IDip)Au(S2C.NHC)](+) (NHC = IPr, IMes) are characterized crystallographically. The IMes.CS2 ligand is also used to prepare functionalized gold nanoparticles with diameters of 11.5 (+/-1.2) and 2.6 (+/-0.3) nm. [less ▲]