화학공학소재연구정보센터
Inorganic Chemistry, Vol.56, No.9, 5316-5327, 2017
Tin(IV) Compounds with 2-C6F4PPh2 Substituents and Their Reactivity toward Palladium(0): Formation of Tin Palladium Complexes via Oxidative Addition
The tin(IV) compounds MexSn(2-C6F4PPh2)(4-x), (1, x = 1; 2, x = 2) and ClSn(2-C6F4PPh2)(3) (3) were obtained from the reactions of 2-LiC6F4PPh2 with MeSnCl3 (3:1), Me2SnCl2 (2:1), or SnCl4 (3:1), respectively. The reactions of 2-LiC6F4PPh2 with SnCl4 in different stoichiometric ratios (4:1-1:1) gave 3 as the main product. Compound Cl2Sn(2-C6F4PPh2)(2) (4) was formed in the transmetalation reaction of 3 and [AuCl(tht)] but could not be isolated. 1 and 2 react with palladium(0) sources {[Pd(PPh3)(4)] and [Pd(allyl)Cp]} by the oxidative addition of one of their Sn-C-Aryl bonds to palladium(0) with formation of the heterobimetallic complexes [MeSn(mu-2-C6F4PPh2)Pd(kappa C-2C(6)F(4)PPh(2))] (5) and [Me2Sn(mu-2-C6F4PPh2)Pd(kappa(2)-2-C6F4PPh2)] (6) featuring Sn-Pd bonds. The reaction of 3 with palladium(0) proceeds via the oxidative addition of the Sn-Cl bond to palladium(0), thus furnishing the complex [Sn(mu-2-C6F4PPh2)(3)PdCl] (7) featuring a Sn Pd bond and a pentacoordinate Pd atom. Transmetalation of Me Sn(2-C6F4PPh2)(4-)x, (x = 1-3) with [Pd(allyl)Cl](2) gave MexClSn(2-C6F4PPh2)(3-x), and [Pd(allyl)(mu-2-C6F4PPh2)](2). For x = 1, the compound MeClSn(2-C6F4PPh2)(2) (generated in situ) reacted with another 1 equiv of [Pd(allyl)Cl](2) by the oxidative addition of the Sn-Cl bond to palladium(0) and the reductive elimination of allyl chloride, thus leading to [MeSn(mu-2C(6)F(4)PPh(2))(2)PdCl] (8). The reductive elimination of allyl chloride was also observed in the reaction of 3 with [Pd(allyl)Cl]2, giving [Sn(mu-2-C6F4PPh2)(3)PdCl] (7). All compounds have been characterized by-means of multinudear NMR spectroscopy, elemental analysis, single-crystal X-ray diffraction, and selected compounds by Sn-119 Mossbauer spectroscopy. Computational analyses (natural localized molecular orbital calculations) have provided insight into the Sn-Pd bonding of 5-8.