Effect of Temperature on the Coordination Chemistry of Cu (II)-Trimethoprim Complexes as Studied by Density Functional Theory

Abstract

Density Functional Theory (DFT) was used for the computational study of two empirically produced copper trimethoprim complexes with distinctly different geometries. Crystallographic information was used to determine the initial geometries of copper-trimethoprim complexes 1, 2, and 3. Using B3LYP/BLYP hybrid density functional methods with 6-31G and LANL2DZ basis sets at 298 and 352 K, the geometries of complexes 1, 2, and 3 were fully optimized. After comparing the obtained results with the actual data, it was determined that complex 1 is the most stable geometry, whereas complex 3 is an unstable/intermediate geometry that can be transformed into a stable form through recrystallization. In addition, when comparing LANL2DZ with 6-31G, the latter foundation set provides more precise results (in terms of experimental validity).