Bistable Molecular Switches Based on Linkage Isomerization in Ruthenium Polypyridyl Complexes with a Ligand-Bound Ambidentate Motif
作者:Olof Johansson、Linus O. Johannissen、Reiner Lomoth
DOI:10.1002/chem.200801208
日期:2009.1.19
Electron‐transfer‐induced linkage isomerization was investigated in a series of bis‐tridentate Ru polypyridyl complexes [Ru(L‐X‐OH)(Y‐tpy)]2+ with ambidentate ligand L‐X‐OH=bpy‐C(R)(OH)‐py (bpy=2,2′‐bipyridine; py=pyridine; R=H, Me, Ph, or tBu) and spectator ligand Y‐tpy (tpy=2,2′:6′,2′′‐terpyridine; Y=p‐tolyl, p‐PhCO2Me, Cl, OEt, N‐pyrrolidine). The ligand‐bound ambidentate motif switches reversibly
电子转移诱导的键异构化研究了一系列具有双配体配体L-X-OH = bpy-C(R )的双三齿Ru聚吡啶基络合物[Ru(L-X-OH)(Y- tpy )] 2+)(OH)-py(bpy = 2,2'-联吡啶; py =吡啶; R = H,Me,Ph或t Bu)和旁观者配体Y-tpy(tpy = 2,2':6',2 ′′-叔吡啶; Y =对甲苯基,p- PhCO 2 Me,Cl,OEt,N-吡咯烷)。配体结合的歧义基序分别在Ru II和Ru III状态下在N和O配位之间可逆切换。Ru III / II的潜力异构体之间的电偶对相差约0.5 V,这导致分子开关的双稳态电化学响应。通过电化学和计算方法研究了取代基形式的结构修饰对环境配体的连接碳原子和旁观者配体的中央吡啶部分的影响。异构化行为的差异涵盖速率常数的六个数量级和平衡常数的两个数量级。可以用空间和电子取代基效应及其对旋转势垒,连接几何形状和金属中心电子缺乏的影响来解释结果。