The Electronic Structure of (Diiminopyridine)cobalt(
<scp>I</scp>
) Complexes
作者:Quinten Knijnenburg、Dennis Hetterscheid、T. Martijn Kooistra、Peter H. M. Budzelaar
DOI:10.1002/ejic.200300569
日期:2004.3
square-planar (LCoR)-R-I complexes of a diiminopyridine ligand are best regarded as containing low-spin Co-II antiferromagnetically coupled to a ligand radical anion. The lowest triplet state, corresponding to a 3d(z)(2)-->pi* excitation, is calculated to be only a few kcal/mol above the ground state, and is thermally accessible. The anomalous H-1 NMR chemical shifts of the LCoR complexes are suggested to
Stable, Cationic Alkyl−Olefin Complexes of Ruthenium(II) and Rhodium(III): Effects of Ligand Geometry upon Olefin Insertion/Alkyl Migration
作者:Eric L. Dias、Maurice Brookhart、Peter S. White
DOI:10.1021/om000674i
日期:2000.11.1
The syntheses of ruthenium(II) and rhodium(III) model complexes of the putative active species in the iron(II)/MMAO polymerization system are reported. The cationic ruthenium methyl ethylene complex 3 is a stable, isolable compound, which does not produce polyethylene under a variety of conditions. Likewise, the analogous rhodiumcomplex 12 shows no appreciable polymerization activity, despite its
Synthesis and properties of a stable, cationic, rhodium Lewis-acid catalyst for hydrosilation, Mukaiyama aldol and cyclopropanation reactions
作者:Eric L. Dias、Maurice Brookhart、Peter S. White
DOI:10.1039/b007815h
日期:——
The remarkably stable cationic, three-coordinate, 14-electron rhodium complex 1 has been synthesized, isolated and used as a catalyst for hydrosilation, Mukaiyamaaldol and cyclopropanation reactions.
Transition Metal Complexes with Sterically Demanding Ligands, 3.<sup>1</sup> Synthetic Access to Square-Planar Terdentate Pyridine−Diimine Rhodium(I) and Iridium(I) Methyl Complexes: Successful Detour via Reactive Triflate and Methoxide Complexes
作者:Stefan Nückel、Peter Burger
DOI:10.1021/om010185y
日期:2001.10.1
The synthesis of novel square-planar, terdentate, aryl-substituted pyridine−diimine Rh(I) and Ir(I) chloro complexes from the free ligands and the bis(μ-chloro) ethylene-bridged dimers [(C2H4)RhIrCl]2 is reported. Since attempts to achieve direct conversion to the corresponding hydride and methyl complexes through metathesis of the chloro ligand in these compounds were unsuccessful, synthetic access
X-ray crystallographic characterization of a related dinuclear N 2 -bridged (pyridinediimine)dirhodium complex. DFT calculations revealed that the formation of dinitrogen complexes is thermodynamically strongly favourable and evidenced that the previous isolation of a terminal iridium-nitrido complex was possible due to a high barrier for the dimerization process and a sizeable barrier for the intramolecular
结合热分析方法(DTG/MS 和 DSC)和 DFT 计算,研究了(吡啶二亚胺)铑-和-铱-叠氮化物配合物的稳定性。在制备规模上,热解产物的分离和 X 射线晶体学表征证实了分子内 CH 活化过程,伴随着 CC、CN、NH 和 Ir-N 键的重组,以产生具有不同配体框架结构的折叠复合物用于 Rh 和 Ir 产品。暂时形成的 (Rh) 或最初存在的 (Ir) 硝基单元被转化为胺 (Rh) 或酰氨基 (Ir) 部分。此外,研究了氮化物复合物二聚化为相应的二氮化合物,即2 L n M≡N → L n MN 2 -ML n 。该步骤相关性的实验证据由相关双核 N 2 -桥连(吡啶二亚胺)二铑配合物的分离和 X 射线晶体学表征提供。DFT 计算表明,二氮复合物的形成在热力学上是非常有利的,并且证明由于二聚化过程的高势垒和分子内 CH 活化步骤的相当大的势垒,先前分离末端铱 - 氮化物复合物是可能的。