Kinetic study of metal-metal bonded rhenium complexes

这个项目的目的是了解氧化态和反应性之间的关系，以及金属与金属之间的相互作用和氧化还原性质之间的关系。在各种氧化态中，Re是用途最广的元素，因此它的配合物最适合于研究金属配合物的氧化还原性能。Hokkaid大学已经制备了各种重要的配合物，外国同事也对它们的反应活性进行了研究。此外，泰恩河畔纽卡斯尔大学的Sayse11博士和奥兰治自由州立大学的Botha博士分别在北海道大学逗留了3个月，为该项目的重大进展做出了贡献。通过使用N，O-和N，N，O型螯合配体，我们分离出了几个具有不完全络合配体的单核稀土(V)配合物。X-射线结构测定揭示了这些络合物的络合形成步骤，信息是…使用易取代的金属离子是不可能获得更多的。在两个相邻的氧化态(III，IV)和(IV，IV)中分离出了双核Re的双氧桥联配合物。它们的结构和氧化还原研究表明，Re-Re键序和氧化还原反应之间存在相关性。对六核硫化Re团簇的研究也揭示了Re-Re键的特征性质。六氢簇合物[Re_6S_8(H_2O)_6]_&lt；2+&gt；与Cl^-或NCS^-的阳离子反应异常缓慢。对于单核Re(III)配合物来说，这种显著的惰性是很难理解的，应该考虑金属-金属键的影响。这种惰性使我们能够制备[Re_6S_8(pyridine)_&lt；6-n&gt；Cl_n]^&lt；(2-n)+&gt；(n=1-3).类型的部分替代物种进一步的研究表明，六茂金属中心的配体之间存在一定的氧化还原作用。我们还研究了一些双核Ru(III)配合物与氧化物和醋酸酯桥的氧化还原反应。氧化桥上的质子化显著改变了二Ru部分的氧化还原电位。质子偶联氧化还原反应与某些酶双金属活性中心的关系已被提出。较少

The purpose of this project is to understand the correlation between the oxidation states and reactivity and that of metal-to-metal interaction and redox properties by using rhenium complexes. Rhenium is the most versatile element with respect to its variety of oxidation states, and thus its complexes are the most appropriate to study redox preperties of metal complexes. Various important complexes have been prepared at Hokkaid Universty, and their reactivities have been studied by the foreign colleagues. Also, Dr.Sayse11 of the University of Newcastle-upon-Tyne and Dr.Botha of the University of Orange-Free-State, stayd at Hokkaido University for 3 months each and contributed to significant progress of the project.By using N,N,N,O-and N,N,O-type chelating ligands, we have isolated several mononuclear rhenium (V) complexes having incompletely chelated ligands. X-Ray structural determination of these complexes revealed complex formation steps of these chelating ligands, information which … More is impossible to obtain by using substitution labile metal ions. Dinuclear rhenium doubly oxo-bridged complexes have been isolated in two neighboring oxidation states, (III,IV) and (IV,IV). Their structural and redox studies show the correlation between the Re-Re bond-order and redox reactions. Study on hexanuclear rhenium sulfide clusters also revealed characteristic properties of Re-Re bond. The hexarhenium cluster, [Re_6S_8(H_2O)_6]_<2+> clusters, shows unexpectedly slow anation reactions with Cl^- or NCS^-. The remarkable inertness is difficult to understand for mononuclear rhenium (III) complexes and the effect of metal-metal bond should be taken into account. This inert nature enabled us to prepare partially substituted species of the type, [Re_6S_8(pyridine)_<6-n>Cl_n]^<(2-n)+>(n=1-3). Further studies to prepare the hexarhenium (III) complexes with pyridine derivative ligands show some redox interaction between the ligands at hexarhenium center.We have also studied redox reactions of some dinuclear ruthenium (III) complexes with oxide and acetate bridges. Protonation at the oxide bridge remarkable change the redox potentials of the diruthenium moiety. Relevance of the proton-coupled redox reactions to some enzyme dimetal active centers have been suggested. Less