Graphitic carbon nitride (CN)-based materials were synthesized using melamine, urea, guanidine carbonate, and thiourea as precursors via pyrolysis. The synthesized materials underwent comprehensive characterization employing techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption-desorption test. These materials were evaluated for their performance as cathodes with platinum sheet electrodes as anodes in the selective electrocatalytic reduction of Sn(Ⅳ) in an acid solution. During the reduction of Sn(Ⅳ) to Sn(Ⅱ), Sn(Ⅱ) can also be reduced to Sn due to the similar reduction potentials of Sn(Ⅱ) and Sn(Ⅳ). The deposition of Sn on the cathode diminishes the electrode conductivity efficiency. Therefore, the electrode material must fulfill the dual requirements of reducing Sn(Ⅳ) to Sn(Ⅱ) while preventing the reduction of Sn(Ⅱ) to Sn. In comparison to conventional cathode materials such as copper plates, graphite plates, ruthenium iridium titanium plates, and platinum plates, the CN demonstrated superior performance in the selective electrocatalytic reduction of Sn(Ⅳ) in an acidic solution. In addition, CN exhibited a lower potential in a dual-electrode electrolytic cell and maintained stability under acidic conditions, enabling the selective reduction of Sn(Ⅳ) to Sn(Ⅱ).

合成了2个丁二酮肟有机锡化合物：双(三(2-甲基-2-苯基丙基)锡)丁二酮肟配合物(C₆H₅C(CH₃)₂CH₂)₃Sn(ON=C(CH₃)C(CH₃)=NO)Sn(CH₂C(CH₃)₂C₆H₅)₃ (1)和二苄基锡氧氯丁二酮肟多核配合物[μ₃-O-((C₆H₅CH₂)₂Sn)₂(ON=C(CH₃)C(CH₃)=NOH)(O)Cl]₂(2)。通过元素分析、红外光谱、核磁共振(¹H、¹³C、¹¹⁹Sn)、差热分析和单晶X射线衍射对配合物进行了结构表征，对其结构进行量子化学从头计算，并进行了体外抗癌活性研究。结果显示：配合物1为通过配体丁二酮肟桥联的双锡核中心对称分子，锡原子均为四配位的畸变四面体构型；配合物2为通过氧原子和丁二酮肟配体桥联的四锡核中心对称多环聚合结构，锡原子分别为五配位的畸变三角双锥构型和六配位的畸变八面体构型。配合物对人肝癌细胞(HUH7)、人肺癌细胞(A549)、人表皮癌细胞(A431)、人结肠癌细胞(HCT-116)和人乳腺癌细胞(MDA-MB-231)均有较强的抑制活性。