Homo- and heteronuclear complexes derived from N-picoline-functionalized benzimidazolin-2-ylidene ligands.

Jahnke, Mareike C.; Hahn, F. Ekkehardt

The transformation of gold(I) complexes of the type [AuCl(NHC)] (NHC = N-picoline-N′-R-functionalized benzimidazolin-2-ylidene ligand; R = Et, 1; R = n-Pr, 2; R = n-Bu, 3) into polynuclear complexes was studied. Chloride abstraction from [AuCl(NHC)] by treatment with silver tetrafluoroborate yielded the digold complexes [Au2(1)2](BF4)2–[Au2(3)2](BF4)2, featuring two gold atoms coordinated by an NHC carbon atom from one NHC ligand and a picoline nitrogen atom from the second NHC ligand each. Treatment of the gold complexes [AuCl(NHC)] (NHC = 1−3) with dicarbene silver complexes of type [Ag(NHC)2][AgBr2] (NHC = 1−3) in the presence of AgBF4 proceeded under transmetalation of the NHC ligand to gold and formation of discrete heterodinuclear di-NHC complexes [AgAu(1)2](BF4)2−[AgAu(3)2](BF4)2, where the two NHC donors bind to the gold atoms, while the two pyridine donors bind to the silver atom. Reaction of the gold(I) complex [AuCl(4)] (4 = N,N′-dipicoline-functionalized benzimidazolin-2-ylidene) with silver(I) complex [Ag(4)2][AgBr2] in the presence of AgBF4 yielded the trinuclear heterobimetallic complex [Ag2Au(4)2](BF4)3 featuring the gold atom coordinated by two carbene donors and the two silver atoms coordinated by the two pyridine donors from one ligand 4. The molecular structures were determined for the homonuclear digold as well as for the heteronuclear AgI/AuI and AgI2/AuI complexes.

MOLECULAR structure; HETEROBIMETALLIC complexes; LIGANDS (Chemistry); GOLD compounds; ATOMS

Zeitschrift für Naturforschung B: A Journal of Chemical Sciences, 2024, Vol 79, Issue 12, p695

0932-0776

Academic Journal

10.1515/znb-2024-0090