Ionic Complexes [Ph3PBu-n][Au(CN)2Cl2] and [Ph3PCH2OMe][Au(CN)2Cl2]: Synthesis and Structure
Abstract
Interaction of triphenyl-n-butylphosphonium bromide and triphenylmethoxymethylphosphonium chloride with potassium dichlorodicyanoaurate in water followed by recrystallization from ethanol has been used to synthesize the novel gold(III) ionic complexes [Ph3PBu-n][Au(CN)2Cl2] (1) and [Ph3PCH2OMe][Au(CN)2Cl2] (2), respectively. They have been structurally characterized. The X-ray diffraction pattern has been obtained at 293 K on an automatic diffractometer D8 Quest Bruker (MoKα-radiation, λ = 0.71073 Å, graphite monochromator) of crystals 1 [C24H24N2PCl2Au, M 639.29; the monoclinic syngony, the symmetry group P2/c; cell parameters: a = 17.790(10), b = 8.750(7), c = 16.295(9) Å; α = 90.00°, β = 95.984(16)°,
γ = 90.00°; V = 2523(3) Å3; the crystal size is 0.51×0.34×0.26 mm; intervals of reflection indexes are –24 ≤ h ≤ 23, –12 ≤ k ≤ 11, –22 ≤ l ≤ 22; total reflections 90802; independent reflections 6806; Rint 0.0538; GOOF 1.029; R1 = 0.0722, wR2 = 0.2385; residual electron density –1.54/7.70 e/Å3] and 2 [C22H20N2PCl2OAu, M 627.24; the triclinic syngony, the symmetry group P–1; cell parameters: a = 8.251(7), b = 9.170(6), c = 16.479(13) Å; α = 77.85(3)°, β = 87.40(4)°, γ = 77.53(4)°;
V = 1190.1(16) Å3; the crystal size is 0.73×0.46×0.43 mm; intervals of reflection indexes are
–12 ≤ h ≤ 12, –14 ≤ k ≤ 14, –25 ≤ l ≤ 25; total reflections 64367; independent reflections 9150; Rint 0.0495; GOOF 1.031; R1 = 0.0735, wR2 = 0.2304; residual electron density –3.87/4.52 e/Å3], the phosphorus atoms have a slightly distorted tetrahedral coordination (the CPC bond angles are 108.2(4)-110.6(5)° (1), 107.5(4)-112.1(4)° (2); the P–C bond lengths are 1.794(9)-1.814(9) Å (1), 1.786(8)-1.798(7) Å (2)). The gold atoms in centrosymmetric crystallographically independent [Au(CN)2Cl2]- anions have a slightly distorted square-planar coordination (the HalAuCl and CAuCtrans-angles are quite close to 180°; the CAuCl cis-angles vary from 86.2(5)° to 93.8(5)°), the Au–Cl bond lengths are 2.418(4) Å and 2.396(2) Å (1), 2.360(2) Å and 2.405(3) Å (2); the Au–C bond lengths are 2.002(14) Å and 2.264(18) Å (1), 1.992(11) Å and 2.102(18) Å (2). The structural organization in crystals 1 and 2 is caused by the weak van-der-Waals interactions: С–HBu∙∙∙N≡C 2.62 Å (1) and C–HPh∙∙∙N≡C 2.66–2.67 Å (2).
