The Trichlorogermanite(II) Anion and its Gold(I) Complexes

Abstract

Tetraphenylphosphonium trichlorogermanite(II) (1) has been prepared (as a reference compound) from Ph4P+ Cl- and GeCl2 (dioxane) in tetrahydronaphthalene. Its structure has been determined by single crystal X-ray methods. The lattice contains independent monomeric GeCl3- anions (Ge-Cl distances between 2.290 and 2.320 Å, Cl-Ge-Cl angles between 95.33 and 98.27°). Treatment of (Ph3As)AuCl with GeCl2 (dioxane) affords (Ph3As)AuGeCl3 in high yields as a germylene insertion product (2). The complex is a dimer in the crystal with a short Au--Au contact of 2.9415(4) Å and bent As-Au-Ge axes [169.353(13)°]. The GeCl3 ligand has shorter Ge-Cl bonds [2.175 to 2.183 Å] and wider Cl-Ge-Cl angles than in the free anion [100.9 to 101.9°]. The analogous reaction with CH2 (AsPh2AuCl)2 leads only to a mono-insertion product in the form of a salt with {[CH2 (AsPh2)2Au]}22+ dications and two [ClAuGeCl3]- anions (3). In the lattice these three ions form a centrosymmetrical tetranuclear unit through short Au--Au contacts. The resulting z-shaped Au--Au--Au--Au chain has distances of 3.0499(6) (twice) and 3.1613(8) Å and angles of 118.833(8)° (twice). The geometry of the GeCl3 units is similar to that in 2. {(Et3N)Au[P(o-Tol)3]}+ PF6- (4) was obtained as a by-product in several reactions with the bulky phosphine and where NEt3 was used as a base. The crystals contain two crystallographically independent cations with a similar core structure, but different conformations of the substituents. Both the P-Au and the N-Au bonds are elongated owing to steric effects.

Coordination Chemistry of Cyclic Disilylated Germylenes and Stannylenes with Group 11 Metals

“…A search in the Cambridge Crystallographic Database (CCDC) 31 reveals Ge–Au distances for complexes with dicoordinate gold between 2.324 and 2.423 Å. 9 , 10 , 32 − 37 For Ge–Ag the distance range is 2.412–2.467 Å, 8 , 34 , 38 − 42 for Ge–Cu a range of 2.287–2.376 Å 42 − 47 was found for tetracoordinate Ge (i.e., germyl groups or base-stabilized germylenes), and two values of 2.214 and 2.249 Å were reported for bonds between non-base-stabilized germylene ligands and copper. 12 For the distance Sn–Au with dicoordinate gold again only a few examples are known with a reported Sn–Au range of 2.565–2.614 Å.…”

“…If cluster compounds are excluded, a rather small number emerges. A search in the Cambridge Crystallographic Database (CCDC) reveals Ge–Au distances for complexes with dicoordinate gold between 2.324 and 2.423 Å. ,,− For Ge–Ag the distance range is 2.412–2.467 Å, ,,− for Ge–Cu a range of 2.287–2.376 Å − was found for tetracoordinate Ge (i.e., germyl groups or base-stabilized germylenes), and two values of 2.214 and 2.249 Å were reported for bonds between non-base-stabilized germylene ligands and copper . For the distance Sn–Au with dicoordinate gold again only a few examples are known with a reported Sn–Au range of 2.565–2.614 Å. , Compounds 3 (Figure ) and 4 (Figure S2), which crystallize in the monoclinic space group P 2­(1)/ c , are isotypic and feature two independent molecules in the asymmetric unit.…”

Unique Digoldgermanes: Structural Characteristics, Dynamic Behaviour and Distinctive Reactions

“…1,16 Although a variety of compounds with gold-germanium bonds have been studied, since the rst report of Glockling and Hooton in 1962, 23 knowledge of the chemistry including the bonding characteristics and reactivities is still limited in gold-monosubstituted germanes [24][25][26][27][28][29][30][31] and germylenes gold complexes. [32][33][34][35][36][37][38][39][40][41] To the best of our knowledge, the isolable digoldgermane is still unknown to date, where two gold atoms are ascribed as halogen-like atom with an oxidation state of -1.…”

A germanium–silver complex containing aGe—Ag bond, Ag[Ge(OC6HPh4-2,3,5,6)3(AgOSO2CF3)]·4C6H6

“…Other Ge II /M I compounds (where M I is a group 11 metal) have been structurally characterized. These contain Ge II bound to Cu I (Orlov et al, 1997;Orlov et al, 1998) and Au I metal centers (Bauer et al, 1995Bauer & Schmidbaur, 1996, 1997Contel et al, 1996;Tripathi et al, 1998). The Ag I cation of compound (I) is encapsulated by the O atoms of the three tetraphenylphenoxide ligands.…”