Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
Org Lett. 2010 Feb 19;12(4):836-9. doi: 10.1021/ol902937k.
A trimethylenemethane (TMM) derivative 1(2*), in which the parent TMM is pi-extended by the symmetric insertion of three pyridine rings into the C-C bonds of TMM, has been synthesized by the alkali metal reduction of the isolated corresponding dication. Although the frozen-glass X-band cw-ESR spectrum of 1(2*) gave unresolved fine structures due to the small ZFS parameters, pulsed ESR two-dimensional electron spin transient nutation (2D-ESTN) spectroscopy unambiguously can afford to identify diradical 1(2*) as a triplet species.
一种三亚甲基甲烷（TMM）衍生物 1(2*)，其中母体 TMM 通过三个吡啶环对称插入到 TMM 的 C-C 键中而被π扩展，已通过分离的相应二阳离子的碱金属还原合成。尽管由于小的 ZFS 参数，1(2*)的冷冻玻璃 X 波段连续波 ESR 光谱给出未解析的精细结构，但脉冲 ESR 二维电子自旋瞬态摆动（2D-ESTN）光谱可以明确地将自由基 1(2*)鉴定为三重态物种。
