含三齿席夫碱配体锇(Ⅵ)的氮合物与CN^(-)的反应活性研究

通过含三齿席夫碱配体锇(Ⅵ)的氮合物mer-[Os^(Ⅵ)(L^(1))(N)(Cl)(H_(2)O)]和不同比例的CN^(-)在乙腈中反应,分别得到了fac-(PPh_(4))[Os^(Ⅵ)(N)(L^(1))(CN)_(2)]和fac-(PPh_(4))_(2)[Os^(Ⅵ)(N)(L^(2))(CN)_(2)]两个配合物。当相同的反应在水中进行时,发现配合物mer-[Os^(Ⅵ)(L^(1))(N)(Cl)(H_(2)O)]易于分解,并分离出产率较低的锇(Ⅵ)的氮合物(PPh_(4))_(2)[Os(L^(3))(CN)_(4)]。通过X射线晶体学确定了配合物fac-(PPh_(4))[Os^(Ⅵ)(N)(L^(1))(CN)_(2)]、fac-(PPh_(4))_(2)[Os^(Ⅵ)(N)(L^(2))(CN)_(2)]和(PPh_(4))_(2)[Os(L^(3))(CN)_(4)]的晶体结构。配合物fac-(PPh_(4))[Os^(Ⅵ)(N)(L^(1))(CN)_(2)]结晶于单斜晶系,P2_(1)/n空间群。通过对堆积图的观察发现,碳与苯环质心的距离为3.508A,说明存在边界面的π--π堆积作用。配合物fac-(PPh_(4))_(2)[Os^(Ⅵ)(N)(L^(2))(CN)2]结晶于三斜晶系,P-1空间群。两个芳香环形成的二面夹角为99.3°,这与配合物fac-(PPh4)[Os^(Ⅵ)(N)(L^(1))(CN)_(2)]中的二面夹角相比要大一点。配合物(PPh_(4))_(2)[Os(L^(3))(CN)_(4)]结晶于正交晶系,Pnma空间群,金属锇中心也是由一个双齿配体L^(3)和四个CN^(-)配体构成的6配位的扭曲的八面体几何构型。配合物mer-[Os^(Ⅵ)(L^(1))(N)(Cl)(H_(2)O)]、fac-(PPh_(4))[Os^(Ⅵ)(N)(L1)(CN)_(2)]和fac-(PPh4)2[Os^(Ⅵ)(N)(L^(2))(CN)_(2)]均通过IR,UV/Ⅵs,CV,ESI/MS和元素分析进行了充分的表征,结果表明,含三齿席夫碱配体锇(Ⅵ)的氮合物与CN^(-)的反应主要发生在配体的C==N官能团上,这可能是含三齿席夫碱配体锇(Ⅵ)的氮合物作为催化剂的催化效率较低的主要原因。

Substituent-regulated highly X-ray sensitive Os(Ⅵ)nitrido complex for low-toxicity radiotherapy

A high efficiency and low toxicity radiosensitizer,OsN(PhenOH)Cl_3,was designed and synthesized through substituent regulation.To the best of our knowledge,this is the first osmium-based coordination complex radiosensitizer.The experimental results shown that this radiosensitizer induced G2/M cell cycle arrest mainly through induction of intracellular ROS overproduction.