The secondary phosphines R(Ar*)PH(R = Me, iPr, Ph, Mes, Ar*) (2a-2h) with bulky aromatic substituents Ar* (Ar* = 2,3,6-R′ 3C6H2, R′ = iPr, tBu) are obtained in good yields by reaction of RPCl2, PCl3, PBr3 or Ar*P(Cl, Br)2 with 2,4,6-tBu3C6H2Li or 2,4,6- iPr3C6H2MgBr and subsequent reduction of the intermediate halophosphines R(Ar*)PX(X = Cl, Br) with LiAlH4. The X-ray structural analysis of Ph(2,4,6-iPr3C6H2)PH (2g), space group P1, shows P-C-distances of 1.824(1) and 1.838(1)Å. The lithium derivatives of 2a-2c are monomeric in solution as indicated by the 1 :1 :1 : 1-quartet 7L i - 31P fine structure of the 31P 1H} NMR signals at low temperatures. 2a-2c and 2f-2h form Ni(0) and Fe(0) complexes (CO)3NiL (6a-6f) and Fe(CO)4L (7a-7d), respectively. The Tolman electronic parameters of the bulky ligands are almost identical. Within the series 2a-2h the spatial shielding of the P atoms has been estimated using advanced molecular modeling techniques. The bulky ligand 2c forms coinage metal complexes [C u(CH3CN)2(2c)2] [PF6] (8), Cu2Cl2(2c)2 (9) and Cl-Au(2c) (10). While 10 is monomeric in solution, in the solid state it forms pairs of head to tail oriented monomers with almost linear Cl - Au - P skeletons (Cl - Au - P 175.47(9)°) as shown by an X-ray structural analysis.
次磷膦R(Ar*)PH(R = Me, iPr, Ph, Mes, Ar*)(2a-2h),其中Ar*为大体积芳香基团(Ar* = 2,3,6-R′3C6H2,R′ = iPr,tBu),通过RPCl2、PCl3、PBr3或Ar*P(Cl,Br)2与2,4,6-tBu3C6H2Li或2,4,6-iPr3C6H2MgBr的反应,并通过还原中间卤代磷膦R(Ar*)PX(X = Cl,Br)与LiAlH4得到高产率。苯基(2,4,6-iPr3C6H2)PH(2g)的X射线结构分析,空间群P1,显示P-C距离为1.824(1)和1.838(1)Å。2a-2c的锂衍生物在溶液中是单体的,如低温下1:1:1:1四重态7Li-31P精细结构的31P 1H} NMR信号所示。2a-2c和2f-2h形成Ni(0)和Fe(0)配合物(CO)3NiL(6a-6f)和Fe(CO)4L(7a-7d),差不多具有相同的Tolman电子参数。在系列2a-2h中,利用先进的分子建模技术估计了P原子的空间屏蔽效应。大体积配体2c形成了铜配合物[Cu(CH3CN)2(2c)2][PF6](8)、Cu2Cl2(2c)2(9)和Cl-Au(2c)(10)。虽然10在溶液中是单体的,但在固态中形成了头对尾定向单体的成对结构,具有几乎线性的Cl - Au - P骨架(Cl - Au - P 175.47(9)°),如X射线结构分析所示。