A study of M–X–BR3 (M = Pt, Pd or Rh; X = Cl or I) interactions in square planar ambiphilic ligand complexes: structural, spectroscopic, electrochemical and computational comparisons with borane-free analogues
作者:David J. H. Emslie、Bradley E. Cowie、Simon R. Oakley、Natalie L. Huk、Hilary A. Jenkins、Laura E. Harrington、James F. Britten
DOI:10.1039/c2dt11991a
日期:——
Reaction of [PtCl2(COD)] and [PtI2(COD)] with 2,7-di-tert-butyl-5-diphenylboryl-4-diphenylphosphino-9,9-dimethylthioxanthene (TXPB) afforded square planar [PtCl2(TXPB)] (1B) and [PtI2(TXPB)] (4B), both of which were crystallographically characterized. Single-crystal X-ray quality crystals were also obtained for [PdCl2(TXPB)] (2B; Emslie et al., Organometallics, 2008, 27, 5317) as 2B·2CH2Cl2 and solvent-free 2B. Both the chloro and iodo TXPB complexes exhibit metalâhalideâborane bridging interactions similar to those in previously reported [RhCl(CO)(TXPB)] (3B) and [RhI(CO)(TXPB)] (5B) (Emslie et al., Organometallics, 2006, 25, 583 and Inorg. Chem., 2010, 49, 4060). To facilitate a more detailed analysis of MâXâBR3 (X = Cl and I) interactions, a borane-free analogue of the TXPB ligand, 2,7-di-tert-butyl-4-diphenylphosphino-9,9-dimethylthioxanthene (TXPH), was prepared. Reaction with [PtX2(COD)] (X = Cl or I), [PdCl2(COD)] and 0.5 [RhCl(CO)2}2] provided square planar [PtCl2(TXPH)] (1H), [PdCl2(TXPH)] (2H), [RhCl(CO)(TXPH)] (3H) and [PtI2(TXPH)] (4H). MâClâBR3 and MâIâBR3 bonding in 1Bâ5B was then probed through the use of structural comparisons, IR and NMR spectroscopy, cyclic voltammetry, and DFT calculations (Slater-type orbitals, Mayer bond orders, Hirshfeld charges, fragment analysis, SCF deformation density isosurfaces, and energy decomposition analysis).
PtCl2(COD)] 和 [PtI2(COD)]与 2,7-二叔丁基-5-二苯基-4-二苯基膦-9,9-二甲基二氧杂蒽 (TXPB) 反应,可得到方形平面的 [PtCl2(TXPB)] (1B) 和 [PtI2(TXPB)](4B),这两种物质都具有晶体学特征。此外,还获得了[PdCl2(TXPB)](2B;Emslie 等人,Organometallics, 2008, 27, 5317)2BÂ-2CH2Cl2 和无溶剂 2B 的单晶 X 射线质量晶体。氯代和碘代 TXPB 复合物都表现出与之前报道的 [RhCl(CO)(TXPB)] (3B) 和 [RhI(CO)(TXPB)] (5B) (Emslie 等,Organometallics,2006,25,583 和 Inorg.Chem.,2010,49,4060)。为了便于更详细地分析 MâXâBR3 (X = Cl 和 I)之间的相互作用,我们制备了 TXPB 配体的无硼烷类似物--2,7-二叔丁基-4-二苯基膦-9,9-二甲基氧杂蒽 (TXPH)。与[PtX2(COD)](X = Cl 或 I)、[PdCl2(COD)]和 0.5 [RhCl(CO)2}2] 反应可得到方形平面的[PtCl2(TXPH)](1H)、[PdCl2(TXPH)](2H)、[RhCl(CO)(TXPH)](3H)和[PtI2(TXPH)](4H)。然后,通过结构比较、红外光谱和核磁共振光谱、循环伏安法以及 DFT 计算(斯莱特型轨道、迈尔键阶、希尔施菲尔德电荷、片段分析、SCF 变形密度等值面和能量分解分析),对 1Bâ5B 中的 MâClâBR3 和 MâIâBR3 键合进行了探究。