Divide and Protect: Passivating Cu(111) by Cu-(benzotriazole)2

Binding of benzotriazolate anion (BTA) to copper complexes and Cu(111) surface was investigated by density functional theory calculations. [BTACuBTA] 1– was found to be a very stable complex that BTAH molecules and copper atoms can form and [BTACuBTA] is energetically preferred over intact BTAH molecule and other BTA-Cu complexes on the Cu(111) surface. At the [BTACuBTA]/Cu(111) interface, all nitrogen atoms can bind to copper, which stabilizes the interface considerably. In this way, [BTACuBTA] can be densely packed on Cu(111). Our study opens new views on the atomic structure of the copper–BTAH interface that is widely used to protect copper and its alloys from corrosion.