Die Pyridinaddukte der Goldhalogenide. 3. Darstellung, Eigenschaften und Kristallstruktur zweier Modifikationen von AuBr · NC₅H₅

Abstract

Bei der Umsetzung von AuBr · S(CH2C6H5)2 mit Pyridin in absolutem Ethanol kristallisiert AuBr · Pyridin in Form trikliner Kristalle mit der Raumgruppe P1 und den Gitterkonstanten a = 791,5(2) pm, b = 935,6(2) pm, c = 1005,1(3) pm, α = 85,78(2)°, β = 102,07(2)°, γ = 109,31(2)°. Wird die Reaktion dagegen in absolutem Toluol durchgeführt, so erhält man eine monokline Modifikation mit der Raumgruppe C2/c und a = 1225,9(2) pm, b = 1522,2(3) pm, c = 1459,7(3) pm, ß = 97,82(2)°. Die Strukturen beider Modifikationen bestehen aus linearen Au(py)2‐ und AuBr2‐Gruppen, die durch schwache Gold‐Gold‐Wechselwirkungen zu kettenförmigen Komplexen verbunden sind. Die trikline Modifikation bildet diskrete Au4‐Zickzack‐Ketten AuBr2—Au(py)2—Au(py)2—AuBr2. In der monoklinen Phase sind die Baugruppen in der Abfolge AuBr2—Au(py)2 zu unendlichen Ketten verknüpft.

A structural survey of metal⋯π heteroaromatic supramolecular synthons for metal = tellurium, tin, and gold

“…4. Similar contacts leading to dimeric units are seen in the closely related gold(I) structures of 13, 45 14, 46 16, 48 and 18. 50 Analogous contacts but extending in two-dimensions are found in the structure of 11, 43 Fig.…”

“…There is also a broader representation of p-systems with 18 structures having Au/p pyridine contacts, four with Au/p pyrimidine, one with Au/p pyrazine, a sole example of a structure with a Au/p 1,4-dithiine contact and one with a Au/p thiopyran contact. Chemical structures for the species participating in Au/p pyridine contacts, 7-24, [39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55] are shown in Scheme 3 and geometric parameters characterising these contacts are collated in Table 2. Seven of the 18 structures feature gold(I) centres and the remaining have gold(III).…”

Gold–Gold Interactions

“…Association of [Au(py) 2 ] þ and [AuX 2 ] À (X ¼ Cl, Br, I) [56,57] ions following the pattern À þ þ À (Figure 2.11a) is another example of aurophilic attraction versus coulombic repulsions. The luminescent complex [Au(Tab) 2 ][Au(CN) 2 ] crystallizes as a tetranuclear species (Figure 2.11b) [53] in which the ions are ordered in the sequence þ À À þ, whereas the corresponding [Au(Tab) 2 ]X 2 (X ¼ PF 6 or I) crystallize as dimers, as commented above.…”

catena-Poly[bromo(ω-thiocaprolactam-κS)gold(I)](Au—Au)

“…Hitherto, three such complexes have been structurally characterized, all with L 1 = Br. With L 2 = pyridine (Conzelmann et al, 1984), the AuÁ Á ÁAu separations are 3.302 and 3.562 A Ê ; with L 2 = o-xylylisocyano, one AuÁ Á ÁAu distance is observed, of 3.348 A Ê (Ecken et al, 1998); ®nally, with L 2 = tetrahydrothiophene (Ahrland et al, 1993), this separation is 3.353 A Ê . Shorter AuÐAu distances are obtained by using bridging ligands, such as thiocarbamates (Bishop et al, 1998), which constrain the geometry of the Au chain (AuÐAu = 2.790 and 3.157 A Ê for the covalent bond and the aurophilic interaction, respectively).…”