中文摘要：

以磺胺嘧啶为模型化合物，基于量子化学密度泛函理论（DFT），通过结构优化及相互作用能的计算，预测Mg^2＋与磺胺嘧啶形成1：1配合物的结构．结果表明，Mg^2＋和磺酰胺基的N和0原子配位，同时结合一个水分子；配合物磺酰胺基的键长、键角和二面角发生明显变化．基于含时密度泛函理论（TD-DFT）方法，计算磺胺嘧啶及其配合物的吸光性质．结果表明，Mg^2＋的配位作用影响前线分子轨道分布和能级，体系吸收光谱发生红移，增强了磺胺嘧啶的吸光能力，实验验证与计算结果基本一致。

英文摘要：

The metal complexation effects were investigated by quantum chemical computations, employing Mg- and sulfadiazine （SDZ） as a model complex system. The structure of 1：1 Mg^2＋-SDZ complex was optimized and the interaction energy was computed based on the density functional theory （DFT）. The light absorption properties of SDZ and its complex were computed based on the time-dependent density functional theory （TD- DFF）. The results indicate that Mg^2＋complexes with N and O of the hydrated SDZ molecule. The bond length, valence and dihedral angles of the complex differ from that of SDZ significantly. The complex has different frontier molecular orbital （FMO） distribution and FMO energy levels. The simulated light absorption of the complex was red-shifted and enhanced compared with SDZ. Tile computed absorption properties of SDZ and the complex were consistent with the experimental results.