A Series of Homoleptic Linear Trimethylsilylchalcogenido Cuprates, Argentates and Aurates Cat[Me₃SiE–M–ESiMe₃] (M = Cu, Ag, Au; E = S, Se)

Abstract

The syntheses and XRD molecular structures of a complete series of silylsulfido metalates Cat[M(SSiMe 3 ) 2 ] (M = Cu, Ag, Au) and corresponding silylselenido metalates Cat[M(SeSiMe 3 ) 2 ] (M = Cu, Ag, Au) comprising lattice stabilizing organic cations (Cat = Ph 4 P + or PPN + ) are reported. Much to our surprise these homoleptic cuprates, argentates, and aurates are stable enough to be isolated even in the absence of any strongly binding phosphines or N-heterocyclic carbenes as coligands. Their metal atoms are coordinated by two silylchalcogenido ligands in a linear fashion. The silyl moieties of all anions show an unexpected gauche conformation of the silyl substituents with respect to the central axis Si− [E−M−E]−Si in the solid state. The energetic preference for the gauche conformation is confirmed by quantum chemical calculations and amounts to about 2−6 kJ/mol, thus revealing a rather shallow potential mainly depending on electronic effects of the metal. Furthermore, 2D HMQC methods were applied to detect the otherwise nonobservable NMR shifts of the 29 Si and 77 Se nuclei of the silylselenido compounds. Preliminary investigations reveal that these thermally and protolytically labile chalcogenido metalates are valuable precursors for the precipitation of binary coinage metal chalcogenide nanoparticles from organic solution and for coinage metal cluster syntheses.

Heavy Chalcogenide‐Based Ionic Liquids in Syntheses of Metal Chalcogenide Materials near Room Temperature

“…In the latest report with respect to the title story we describe the syntheses and crystallographically determined molecular structures of unprecedented homoleptic trimethylsilylsulfido and trimethylsilylselenido cuprates, argentates and aurates Cat + [M(SSiMe 3 ) 2 ] À and Cat + [M(SeSiMe 3 ) 2 ] À (M = Cu, Ag, Au) comprising stabilizing Ph 4 P + or PPN + cations. [30] Much to our surprise these homoleptic coinage metalate anions are stable enough to be isolated even in the absence of any other strongly metal binding and stabilising ligands such as phosphines or Nheterocyclic carbenes. The complete series of metalates with all six element combinations has been characterized by XRD analysis.…”

“…Preliminary investigations reveal, that these thermally and protolytically labile chalcogenido metalates are valuable precursors for the precipitation of binary coinage metal chalcogenide nanoparticles from organic solution or ILs and for coinage metal cluster syntheses. [30]…”