Inductive influence of 4′-terpyridyl substituents on redox and spin state properties of iron(II) and cobalt(II) bis-terpyridyl complexes
作者:Joseph Chambers、Bryan Eaves、Danny Parker、Ronald Claxton、Partha S. Ray、Spencer J. Slattery
DOI:10.1016/j.ica.2005.12.065
日期:2006.5
Cyclic voltammetry was used to assess the substituentsinfluence on the M(III/II) redox couple. A plot of the M(III/II) redox potential ( E 1/2 ) versus the electron donating/withdrawing nature of the substituents (Hammett constants), shows a strong linear trend for both metals; however, the substituents were observed to have a stronger influence on the Fe(III/II) couple. Solution magnetic susceptibility
摘要制备了一系列具有通式[M(R-terpy)2](PF 6)2的铁和钴的双联吡啶(叔丁基)配合物,其中M表示Co(II)和Fe(II),R是下列吡啶吡啶取代基,以增加吸电子性能的顺序排列[[(C 4 H 8)N,(C 4 H 9)NH,HO,CH 3 O,CH 3-苯基,H,Cl,CH 3 SO,CH 3 SO 2]。制备复合物以研究氧化还原和自旋态控制的程度,这可以通过使用三联吡啶配体上的单个取代基位点简单地改变给电子/吸电子的影响来实现。循环伏安法用于评估取代基对M(III / II)氧化还原对的影响。M(III / II)氧化还原电势(E 1/2)与取代基的给电子/吸电子性质(Hammett常数)的关系图,两种金属都显示出很强的线性趋势;然而,观察到取代基对Fe(III / II)对具有更强的影响。使用标准NMR方法(改良的Evans方法)在室温下进行溶液磁化率测量,其中所有Fe(II)配合物均表现出抗磁性,低自旋(S