Synthesis of a Novel Series of 6,6'-Disubstituted 4,4'-Bipyrimidines by Radical Anion Coupling: New π-Accepting Ligands for Coordination Chemistry
作者:Elena Ioachim、Elaine A. Medlycott、Matthew I. J. Polson、Garry S. Hanan
DOI:10.1002/ejoc.200500335
日期:2005.9
A new family of 6,6'-disubstituted 4,4'-bipyrimidine ligands has been prepared and characterized. The reduction potentials of the new ligands, as determined by cyclic voltammetry, indicate that these new ligands are considerably better π-acceptors than the ubiquitous 2,2'-bipyridine ligand, and are even superior to the parent unsubstituted 4,4'-bipyrimidine ligand. The substituents in 6,6' positions
一个新的 6,6'-二取代 4,4'-联嘧啶配体家族已被制备和表征。通过循环伏安法测定的新配体的还原电位表明,这些新配体是比普遍存在的 2,2'-联吡啶配体更好的 π-受体,甚至优于未取代的母体 4,4'-联嘧啶配体。4,4'-联嘧啶的 6,6' 位置的取代基也会导致整个 UV 区域的 ππ* 和 nπ* 吸收发生红移。双嘧啶家族成员的 X 射线晶体结构表明,芳基取代基在固态时可以与嘧啶环共面。嘧啶环上的芳基取代基提供的额外电子离域作用有助于这些化合物更好的接受 π 能力。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)