N -Heterocyclic Carbene Coinage Metal Complexes of the Germanium-Rich Metalloid Clusters [Ge 9 R 3 ] ? and [Ge 9 R I 2 ] 2 ? with R = Si( i Pr) 3 and R I = Si(TMS) 3

摘要

We report on the synthesis of novel coinage metal NHC ( N -heterocyclic carbene) compounds of the germanium-rich metalloid clusters [Ge 9 R 3 ] ? and [Ge 9 R I 2 ] 2 ? with R = Si( i Pr) 3 and R I = Si(TMS) 3 . NHC Dipp Cu{η 3 Ge 9 R 3 } with R = Si( i Pr) 3 ( 1 ) represents a less bulky silyl group-substituted derivative of the known analogous compounds with R = Si( i Bu) 3 or Si(TMS) 3 . The coordination of the [NHC Dipp Cu] + moiety to the cluster unit occurs via one triangular face of the tri-capped trigonal prismatic [Ge 9 ] cluster. Furthermore, a series of novel Zintl cluster coinage metal NHC compounds of the type (NHC M ) 2 {η 3 Ge 9 R I 2 } (R I = Si(TMS) 3 M = Cu, Ag and Au; NHC = NHC Dipp or NHC Mes ) is presented. These novel compounds represent a new class of neutral dinuclear Zintl cluster coinage metal NHC compounds, which are obtained either by the stepwise reaction of a suspension of K 12 Ge 17 with Si(TMS) 3 Cl and the coinage metal carbene complexes NHC M Cl ( M = Cu, Ag, Au), or via a homogenous reaction using the preformed bis-silylated cluster K 2 [Ge 9 (Si(TMS) 3 ) 2 ] and the corresponding NHC M Cl ( M = Cu, Ag, Au) complex. The molecular structures of NHC Dipp Cu{η 3 Ge 9 (Si( i Pr) 3 ) 3 } ( 1 ) and (NHC Dipp Cu) 2 {η 3 -Ge 9 (Si(TMS) 3 ) 2 } ( 2 ) were determined by single crystal X-ray diffraction methods. In 2 , the coordination of the [NHC Dipp Cu] + moieties to the cluster unit takes place via both open triangular faces of the [Ge 9 ] entity. Furthermore, all compounds were characterized by means of NMR spectroscopy ( 1 H, 13 C, 29 Si) and ESI-MS.