四Schiff碱(二苯并-18-冠-6)及其钾(I)/钴(II)配合物的合成和 性质

由二苯并-18-冠-6出发,合成了4',4',5',5'-四(2-羟基苯亚甲基亚氨基)二苯并-18-冠-6(L^1H~4)及其5位取代衍生物(取代基R=CH~3,OH,OCH~3,Cl,NO~2)L^2H~4～L^6H~4。它们依次与硝酸钾和醋酸钴反应,制得1:1:2的钾(I)/双钴(II)配合物LCo~2.2H~2O.KNO~3(L=L^5,L^6)或其某些二氧加合物LCo~2(2O~2).2H~2O.KNO~3(L=L^1～L^4)。考察了取代基R和冠醚环配合的钾离子对二氧加合物形成及稳定性的影响。结果表明,含吸电子基(R=Cl,NO~2)的钾(I)/双钴(II)配合物不能形成二氧加合物;冠环中的钾离子会导致二氧加合物中两个Co-O~2键热稳定性的差异。

Synthesis and properties of K(I)/Co(II) complexes with (18-crown-6) disalophen and its substituted derivatives

4', 4', 5', 5'-tetra (2-hydroxyl-benzylideneimino) dibenzo-18- crown-6 (L^1H~4) and its 5-substituted derivatives (substituted group R=CH~3, OH, OCH~3, Cl, NO~2) L^2H~4～L^6H~4 have been synthesized from dibezno-18-crown-6 as starting material. The L^1H~4～L^6H~4 react successively with potassium nitrate and cobalt acetate in air to form 1:1:2 potassium (I)/dicobalt (II) complexes LCo~2.2H~2O. KNO~3 (L=L^5, L^6) or their dioxygen adducts LCo~2(2O~2).2H~2O.KNO~3 (L=L^1～L^4). The influence of the substituted groups R in ligands and potassium ion in the crown ring on formation and stability of dioxygen adducts was investigated. The results indicate that potassium (I)/dicobalt (II) complexes containing electron-withdrawing group (R=Cl, NO~2) can not form dioxygen adducts. Potassium ion in the crown ring leads to difference in the thermostability of the two Co-O~2 bonds in dioxygen adducts. The TG analysis of dioxygen adducts shows that one in two O~2 of LCo~2(2O~2).2H~2O.KNO~3 (L=L^1～L^4) was first lost at 51～115℃ and then the other O~2 was extricated at 125～ 216℃. However, two O~2 molecules in LCo~2(2O~2).2H~2O without potassium ion were liberated together at 51～111℃.