Semicarbazide (OC(NH2)(N2H3)) and thiosemicarbazide (SC(NH2)(N2H3)) are well-known for their coordination complex formation ability. They contain nonbonding electrons in the form of heteroatoms (N, O and S) and π-electrons in the form of >C=O and >C=S through they strongly coordinate with the metal atoms and ions. Because of their association with this property, the Semicarbazide (SC), thiosemicarbazide (TSC) and their derivatives are widely used for different applications. They serve as building blocks for synthesis of various industrially and biologically useful chemicals. The SC, TSC and they derivatives are also serve as strong aqueous phase corrosion inhibitors. In the present reports, the coordination ability and corrosion protection tendency of Semicarbazide (SC), thiosemicarbazide (TSC) and their derivatives is surveyed and described. These compounds are widely used as inhibitors for different metals and alloys. Through their electron rich sites they adsorb on the metal surface and build corrosion protective film. Their adsorption mostly followed the Langmuir adsorption isotherm. Through their adsorption they increase the value of charge transfer resistance and decrease the value of corrosion current density. Computational studies adopted in the literature indicate that SC, TSC and their derivatives adsorb flatly and spontaneously using charge transfer mechanism.

中文翻译：

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氨基脲的缓蚀相关性：电子结构、反应性和配位化学

氨基脲（OC(NH2)(N2H3)) 和氨基硫脲 (SC(NH2)(N2H3)) 以其配位络合物的形成能力而闻名。它们包含杂原子（N、O 和 S）形式的非键电子和 >C=O 和 >C=S 形式的 π 电子，因为它们与金属原子和离子强烈配位。由于它们与这种性质的关联，氨基脲 (SC)、氨基硫脲 (TSC) 及其衍生物被广泛用于不同的应用。它们作为合成各种工业和生物有用化学品的基石。SC、TSC 及其衍生物也可用作强水相缓蚀剂。在本报告中，对氨基脲（SC）、氨基硫脲（TSC）及其衍生物的配位能力和防腐趋势进行了调查和描述。这些化合物被广泛用作不同金属和合金的抑制剂。通过它们的富电子位点，它们吸附在金属表面并形成腐蚀保护膜。它们的吸附主要遵循朗缪尔吸附等温线。通过它们的吸附，它们增加了电荷转移电阻的值并降低了腐蚀电流密度的值。文献中采用的计算研究表明，SC、TSC 及其衍生物利用电荷转移机制进行平坦且自发的吸附。