Single-Crystalline Thin Films by a Rare Molecular Calcium Carboxyphosphonate Trimer Offer Prophylaxis From Metallic Corrosion
2010
Abstract
In this communication, we report the synthesis and crystallographic characterization of a rare molecular linear trimer composed of Ca2+ and a carboxyphosphonate (hydroxyphosphonoacetate, HPAA), namely Ca-3(HPAA)(2)(H2O)(14). The two HPAA(3-) ligands function as bridges between the three Ca2+ ions.
The central Ca2+ center is found in an octahedral environment, whereas the peripheral Ca2+ centers are in an 8-coordinated environment. This Ca-3(HPAA)(2)(H2O)(14) trimer was found to be an effective corrosion inhibitor for carbon steel surfaces at pH 7.3.
Furthermore, we have proven by a variety of techniques that the identity of the anticorrosion film is the same as the rationally synthesized Ca-3(HPAA)(2)(H2O)(14).