Synthesis, reactivity, spectroscopic characterization, X-ray structures, PGSE, and NOE NMR studies of (eta5-C5Me5)-rhodium and -iridium derivatives containing bis(pyrazolyl)alkane ligands.
Synthesis, reactivity, spectroscopic characterization, X-ray structures, PGSE, and NOE NMR studies of (eta5-C5Me5)-rhodium and -iridium derivatives containing bis(pyrazolyl)alkane ligands.
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DOI：
10.1021/ic061928g
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发表时间：
2007-01
影响因子：
4.6
通讯作者：
C. Pettinari;R. Pettinari;F. Marchetti;A. Macchioni;D. Zuccaccia;B. Skelton;Allan H. White
中科院分区：
文献类型：
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作者：
C. Pettinari;R. Pettinari;F. Marchetti;A. Macchioni;D. Zuccaccia;B. Skelton;Allan H. White
含双的铑（III）和铱（III）配合物吡唑甲烷配体（pz =吡唑，一般为L';具体地，L1 = H2 C（pz）2，L2 = H2 C（pzMe 2）2，L3 = H2 C（pz 4 Me）2，L4 = Me 2C（pz）2），已经在探索这些配体对[Cp*MCl（mu-Cl）]2二聚体的反应性的研究中制备（M = Rh，Ir; Cp* =五甲基溴）。当反应在丙酮溶液中进行时，得到了[Cp*M（L '）Cl]Cl型配合物。然而，当L1和L2配体与过量的[Cp*MCl（μ-Cl）]2一起使用时，已经观察到[Cp*M（L '）Cl][Cp* MCl 3]物质的形成。PGSE NMR测量已经进行了这些配合物，其中的counterparts是一个金属络合物，在CD 2Cl 2作为浓度的函数。的流体动力学半径（RH），因此，所有的物种的流体动力学体积（VH）已被确定从测量的平移自扩散系数（Dt），表明在溶液中的离子对的优势。NOE测量和X-射线单晶研究表明，[Cp* MCl 3]-接近阳离子，定向的三个Cl-腿的“钢琴凳”对CH 2部分的双（吡唑基）甲烷配体。1当量的[Cp*M（L '）Cl]Cl或[Cp*M（L'）Cl][Cp* MCl 3]与1当量的AgX的反应（X = ClO_4或CF_3SO_3）在CH_2Cl_2中反应生成[Cp*M（L ′）Cl]X，而1当量[Cp*M（L ′）Cl]与2当量AgX反应生成双阳离子配合物[Cp*M（L ′）（H_2 O）][X]_2，其中单个水分子直接与金属原子键合。通过X射线晶体学研究证实了一些配合物的固态结构。[Cp*Ir（L '）（H2O）][X]2与甲酸铵在水或丙酮溶液中的反应允许生成氢化物物种[Cp*Ir（L'）H][X]。
Rhodium(III) and iridium(III) complexes containing bis(pyrazolyl)methane ligands (pz = pyrazole, L' in general; specifically, L1 = H2C(pz)2, L2 = H2C(pzMe2)2, L3 = H2C(pz4Me)2, L4 = Me2C(pz)2), have been prepared in a study exploring the reactivity of these ligands toward [Cp*MCl(mu-Cl)]2 dimers (M = Rh, Ir; Cp* = pentamethylcyclopentadienyl). When the reaction was carried out in acetone solution, complexes of the type [Cp*M(L')Cl]Cl were obtained. However, when L1 and L2 ligands have been employed with excess [Cp*MCl(mu-Cl)]2, the formation of [Cp*M(L')Cl][Cp*MCl3] species has been observed. PGSE NMR measurements have been carried out for these complexes, in which the counterion is a cyclopentadienyl metal complex, in CD2Cl2 as a function of the concentration. The hydrodynamic radius (rH) and, consequently, the hydrodynamic volume (VH) of all the species have been determined from the measured translational self-diffusion coefficients (Dt), indicating the predominance of ion pairs in solution. NOE measurements and X-ray single-crystal studies suggest that the [Cp*MCl3]- approaches the cation, orienting the three Cl-legs of the "piano-stool" toward the CH2 moieties of the bis(pyrazolyl)methane ligands. The reaction of 1 equiv of [Cp*M(L')Cl]Cl or [Cp*M(L')Cl][Cp*MCl3] with 1 equiv of AgX (X = ClO4 or CF3SO3) in CH2Cl2 allows the generation of [Cp*M(L')Cl]X, whereas the reaction of 1 equiv of [Cp*M(L')Cl] with 2 equiv of AgX yields the dicationic complexes [Cp*M(L')(H2O)][X]2, where single water molecules are directly bonded to the metal atoms. The solid-state structures of a number of complexes were confirmed by X-ray crystallographic studies. The reaction of [Cp*Ir(L')(H2O)][X]2 with ammonium formate in water or acetone solution allows the generation of the hydride species [Cp*Ir(L')H][X].