- Gold(I) phosphine complexes: Mercaptooxopurine base interactions. Molecular and crystal structure of (8-mercaptotheophyllinato-S)(triphenylphosphine)gold(I)
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The interaction of chloro(triphenylphosphine)gold(I) and [μ-1,2-bis(diphenylphosphino)ethane]bis[bromogold(I)] with mercaptooxopurine derivatives (8-mercaptotheophylline, 8-mercapto-2-thiotheophylline, and 8-(methylthio)theophylline) under basic conditions yields complexes of the type [Au(PPh3)L], [{Au(PPh3)}2(μ-L)], [Au(μ-dppe)(μ-L)Au], and [LAu(μ-dppe)AuL] [L = mercaptooxopurine anion, dppe = 1,2-bis(diphenylphosphino)ethane], which contain either one S8-bonded or two N7,S8-bonded gold(I) phosphine groups. These complexes were characterized by means of 1H, 13C, and 31P NMR and IR spectroscopy. Besides this, the crystal structure of the complex (8-mercaptotheophyllinato)(triphenylphosphine)gold(I) was determined from X-ray diffraction data. The compound crystallizes in triclinic space group P1 with a = 8.035 (1) A?, b = 12.749 (5) A?, c = 13.172 (4) A?, α = 102.89 (5)°, β = 103.03 (2)°, γ = 103.77 (5)°, V = 1221.0 (8) A?3, Z = 2, R = 0.037, and Rw = 0.039. The structure consists of neutral [Au(PPh3)(HL1)] (HL1 = 8-mercaptotheophyllinato anion) held together in pairs by two N7-H - O6 hydrogen bonds and related by a crystallographic center of inversion. The coordination of the gold atom is almost linear, P-Au-S8 = 178.6 (2)°, with Au-S and Au-P bond distances of 2.308 (2) and 2.256 (2) A°, respectively. The substitution reaction between [Au(PPh3)(HL1)] and [(AuBr)2(μ-dppe)] to give the complex [Au(μ-dppe)(μ-L1)Au] was studied. It seems that the reaction takes place through the intermediate complexes K[(L1)Au(μ-dppe)AuBr]·4H2O and [{Au(PPh3)}2(μ-L1)].
- Colacio, Enrique,Romerosa, Antonio,Ruiz, José,Román, Pascual,Gutiérrez-Zorrilla, Juan M.,Vegas, Angel,Martínez-Ripoll, Martín
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p. 3743 - 3749
(2008/10/08)
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