220931-40-8Relevant academic research and scientific papers
Synthesis, structure and reactivity of sulfur-rich [Fe(L1)(L2)('tpS4')] complexes with rigid [Fe('tpS4'] cores and σ-π co-ligands ('tpS4'2- = 1,2-bis(2-mercaptophenylthio)phenylene(2-); L1 L2 = CO, PR3, NO)
Sellmann, Dieter,Blum, David C. F.,Heinemann, Frank W.,Sutterial, Joerg
, p. 418 - 426 (2003)
Optimisation of synthesis and purification steps has made the new ligand 'tpS42- available in preparative amounts. Treatment of FeC12.4H2O with 'tpS4-Li2 or 'tpS4'-Na2 yielded [Fe('tpS4')] (1), which in the solid state and in the absence of co-ligands probably trimerises to give paramagnetic [Fe('tpS4')]3. The [Fe('tpS4')] fragment displays helical coordination of the 'tpS4'2 -ligand and binds σ-π ligands such as CO, NO and phosphanes to give diamagnetic 18-valence-electron complexes of general formula [Fe(L1)(L2) ('tpS4')]. The cis-dicarbonyl complex [Fe(CO)2('tpS4')] (2) is labile and readily dissociates CO to give dinuclear [Fe(CO)('tpS4')]2 (3). Simultaneous coordination of CO and phosphanes yielded [Fe(CO)(PR3)('tpS4')] with R = Me (4), Et (5), Pr (6) and Bu (7), but it proved impossible to obtain analogous complexes with bulky PPh3 or PCy3 ligands. Bis(phosphane) complexes could be obtained only with PMe3 and the bidentate dppe, which yielded [Fe(PMe3)2('tpS4')] (8) and [Fe(dppe)('tpS4')] (11). Alkylphosphanes with longer alkyl substituents, such as PnPr3 and PnBu3, gave the labile derivatives [Fe(PR3)2-('tpS4')] with R = nPr (9) and nBu (10). Complexes 9 and 10 reversibly dissociate one PR3 ligand, yielding diamagnetic [Fe(PR3)('tpS4')] fragments. These findings explain the decisive and hitherto inexplicable influence of PPr3 and PBu3 ligands upon the stabilisation of N2H2 in the diazene complexes [μ-N2H2{Fe(PR3) ('tpS4')}2] with R = Pr, Bu. Treatment of [Fe('tpS4')] (1) or [Fe(CO)('tpS4')]2 (3) with NO or NO+ yielded [Fe(NO)2('tpS4')] (12). The molecular structures of 3, 4, 7 and 8 were determined by X-ray structure analysis. Spectroscopic and structural results indicate that the differences in reactivity between [Fe(L1)(L2)('tpS4')] and homologous [Fe(L1)(L2) ('S4')] complexes can be traced back to subtle electronic and structural effects. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
Transition metal complexes with sulfur ligands, 134 [(+)] - Synthesis of the tetradentate thioether amine and thioether thiolate ligands 1,2 bis(2 aminophenylthio)phenylene and 1,2 bis(2 mercaptophenylthio)phenylene and some representative six-coordinate ruthenium and osmium complexes
Sellmann, Dieter,Engl, Klaus,Gottschalk-Gaudig, Torsten,Heinemann, Frank W.
, p. 333 - 339 (2007/10/03)
In search of a tetradentate thioether thiolate ligand that is more stable toward reductive C-S bond cleavage than the parent ligand 'S4'-H2 ['S4'-H2 = 1,2-bis(2-mercaptophenylthio)ethane], the novel tris-phenylene ligand 'tpS4'H2 (3) ['tpS4'-H2 = 1,2-bis(2-mercaptophenylthio)phenylene] was synthesized via the nitro and amine compounds 'tpS2(NO2)2' (1) and 'tpS2(NH2)2' (2). The coordination of 'tpS4'2- to ruthenium centers resulted in the formation of six-coordinate [Ru(L)(PR3)('tpS4')] complexes (R = Et, L = PEt3 4; R = Ph, L = PPh3 5, CO 6, DMSO 7). The X-ray structure analyses of 4 and 6 revealed that the thiolate donors occupy trans positions; consequently the 'tpS4'2- ligand coordinates in the same way as the 'S4'2- ligand. The stability of the 'tpS4'2- ligand toward reductive C- S cleavage reactions was shown by the synthesis of [Os(PEt3)2('tpS4')] (8). In contrast to [Os(PEt3)2('S4')], 8 is stable for unlimited periods of time. The X-ray structure analysis of [Ru(Cl)2(PPh3)('tpS2(NH2)2')] (9) demonstrates that the potentially tetradentate ligand 'tpS2(NH2)2' coordinates in 9 through three donors leaving one NH2 donor dangling.
