The reaction of the di-lithiated oxamide of 1 with two equivalents of SnCl2 provided the tin trans-oxamide 3. In solution, spectroscopic analysis suggests exclusively the formation of a trans-oxamide (trans-3). However, the solid state shows an atypical cis-oxamide (cis-3), where the oxamide fragment acts as an anti-Janus head ligand. An 119Sn-NMR variable temperature experiment ([D8]THF) of the trans-oxamide
1 的二
锂化草酰胺与两当量的 SnCl 2 的反应提供了
锡反式草酰胺 3。在溶液中,光谱分析表明仅形成了反式草酰胺 (trans-3)。然而,固态显示出非典型的顺式草酰胺 (cis-3),其中草酰胺片段充当抗 Janus 头
配体。然而,进行了反式草酰胺 (trans-3) 的 119Sn-NMR 变温实验 ([D8]THF),但在较低温度下没有观察到额外的信号,这证实了不存在动态平衡。分散校正的密度泛函计算表明,这种
锡 (II) 草酰胺配合物的顺式构象比反式异构体稳定 1.4 kcal·mol–1。