146816-58-2Relevant academic research and scientific papers
Use of the new ligand P(CH2CH2PCy2)3 in the synthesis of dihydrogen complexes of iron(II) and ruthenium(II)
Jia, Guochen,Drouin, Samantha D.,Jessop, Philip G.,Lough, Alan J.,Morris, Robert H.
, p. 906 - 916 (2008/10/08)
The novel bulky and basic tetradentate ligand P(CH2CH2PCy2)3 (PP3Cy) is synthesized by the LiN(i-Pr)2-catalyzed addition reaction of dicyclohexylphosphine (HPCy2) to P(CH=CH2)3. Treatment of RuCl2(PPH3)3 with PP3Cy produces the five-coordinate square-pyramidal complex [RuCl(PP3Cy)]Cl, which is converted into [RuCl(PP3Cy)]BPh4 when treated with NaBPh4. Similarly, FeCl2 reacts with PP3Cy to give [FeCl(PP3Cy)]Cl. The structure of the tetraphenylborate salt [FeCl(PP3Cy)]BPh4 is trigonal bipyramidal around Fe(II); crystals are monoclinic, space group P21/c, with a = 12.699(4) ?, b = 29.046(16) ?, c = 17.026(7) ?, β = 103.14(3)°, and V = 6116(5) ?3 for Z = 4; R = 0.065. Reaction of [RuCl(PP3Cy)]Cl with excess NaBH4 in THF yields mer-RuH(η2-BH4)(η3-PP 3Cy·BH3), where the tetraphosphine is bound via three P atoms to ruthenium and the BH3 is bound to a dangling terminal PCy2 group of the tetraphosphine. The monohydride complex RuHCl(PP3Cy) is obtained from the reaction of [RuCl(PP3Cy)]Cl with excess NaOMe in refluxing THF. The η2-dihydrogen complex [RuH(η2-H2)(PP3Cy)]BPh4 is synthesized by treating [RuCl(PP3Cy)]BPh4 with 1 equiv of NaBH4 under an atmosphere of dihydrogen. The analogous iron complex is also described. The nonclassical structures of [MH(η2-H2)(PP3Cy)]BPh4 (M = Fe, Ru) are established by 1H, 31P, and T1 NMR measurements and the observation of a 1J(HD) coupling constant of 28 Hz in the isotopomer [RuD(HD)(PP3-Cy)]+. Despite the steric bulk of the ligand, the complexes adopt an octahedral geometry, [MH(H2)(PP3Cy)]+, instead of a trigonal-bipyramidal ligand geometry with an H3 ligand.
