Retention of single crystals of two Co(<scp>ii</scp>) complexes during chemical reactions and rearrangement
作者:Shaikh M. Mobin、Akbar Mohammad
DOI:10.1039/c4dt01312c
日期:——
Monomeric [CoII(hep-H)(H2O)4]SO4 [1]SO4 and [CoII(hep-H)2(H2O)2](NO3)2 [2](NO3)2 have been developed from 2-(2-hydroxyethyl)pyridine (hep-H) and CoSO4·7H2O/Co(NO3)2·6H2O, respectively, at 298 K. On exposure to heat (120 °C), the light orange single crystal of [1]SO4 transforms to a pink single crystal corresponding to the neutral sulfato bridged dimeric complex [(CoII(hep-H)(H2O)2(μ2-sulfato-O,O′))2](3). However, the orange single crystal of [2](NO3)2 transforms to the single crystal of monomeric [CoII(hep-H)2(NO3)]NO3 [4]NO3 (orange) upon exposure to heat (110 °C) where one of the NO3− counter anions in [2](NO3)2 moves to the coordination sphere. The facile SCSC transformations of [1]SO4 (orange) → 3 (pink) and [2](NO3)2 (orange) → [4]NO3 (orange) involve intricate multiple bond breaking and bond forming processes without losing the crystallinity. Moreover, the immersion of the pink single crystal of 3 in 1 N HCl results in a green single crystal of ionic monomeric [CoII(H2O)6]·SO4[5]SO4, which indeed demonstrates the unprecedented unique two-step SCSC transformations.
在 298 K 下,分别从 2-(2-羟乙基)吡啶 (hep-H) 和 CoSO4-7H2O/Co(NO3)2-6H2O 生成了单体 [CoII(hep-H)(H2O)4]SO4 [1]SO4 和 [CoII(hep-H)2(H2O)2](NO3)2 [2](NO3)2。受热(120 °C)后,[1]SO4 的浅橙色单晶转变为粉红色单晶,对应于中性硫桥二聚体复合物[(CoII(hep-H)(H2O)2(μ2-sulfato-O,O′))2](3)。然而,[2](NO3)2 的橙色单晶在受热(110 °C)后转变为单质[CoII(hep-H)2(NO3)]NO3 [4]NO3(橙色)的单晶,其中 [2](NO3)2 中的一个 NO3- 反阴离子移动到了配位层。[1]SO4(橙色)→3(粉红色)和[2](NO3)2(橙色)→[4]NO3(橙色)的简易 SCSC 转化涉及复杂的多重断键和成键过程,但不会失去结晶性。此外,将粉红色的 3 单晶浸入 1 N HCl 后,会生成绿色的离子单质 [CoII(H2O)6]-SO4[5]SO4 单晶,这确实展示了前所未有的独特的两步 SCSC 转变。