Synthesis and Structure of a Nucleoside with π-Conjugated Nitroxide Spin Label Forming a One-Dimensional Ferromagnetic Chain

Spin labeled 2‘-deoxyuridine, in which a significant fraction of the spin density is delocalized from a nitroxide radical to the DNA base residue, was prepared as a crystalline solid, stable at ambient conditions. The crystal packing, which includes multiple hydrogen bonds, leads to one-dimensional chains of molecules with predominant intrachain ferromagnetic coupling and weaker interchain antiferromagnetic coupling.

本研究成功制备了自旋标记2'-脱氧尿苷（2'-deoxyuridine），该化合物中相当比例的自旋密度从氮氧自由基（nitroxide radical）离域至DNA碱基残基（DNA base residue），其产物为晶体固体，在环境条件下可稳定存在。该晶体的堆积结构包含多重氢键，可形成一维分子链，链内以铁磁耦合（ferromagnetic coupling）为主，链间则存在较弱的反铁磁耦合（antiferromagnetic coupling）。