Estudo das propriedades estruturais e vibracionais do bis(L-Treoninato de Cobre (II)) monohidratado em altas pressões

Abstract

Amino acids are essential organic compounds in protein synthesis and exhibit a wide range of technological applications. Their vibrational and structural properties—especially in crystalline form and as part of molecular complexes—have been extensively investigated to understand phenomena such as pharmaceutical polymorphism, biological system architecture, and confor mations of more complex molecules like peptides and proteins. However, purely organic crystals often suffer from limited physicochemical stability. The complexation with metal ions enables the formation of stable hybrid crystals, known as metal–organic materials, which merge the functionality of organic ligands with the electronic and structural properties of metals. This synergy yields compounds with enhanced potential for functionalization and tunable optical, magnetic, and catalytic behaviors. This study presents the vibrational analysis of the metal complex bis(L-threoninate copper(II)) monohydrate under varying pressure conditions from ambient up to 6.4 GPa, across the spectral range of 100 cm−1 to 3400 cm−1. Raman spectroscopy measurements combined with theoretical simulations via Density Functional Theory (DFT) show strong agreement between theoretical and experimental spectra, allowing for accurate vibrational mode assignments. Spectroscopic analysis under extreme pressure reveals the merging and disappearance of specific vibrational modes between 4 and 5 GPa, along with band broadening as pressure increases. These findings suggest changes in intermolecular interactions without drastic alterations to the crystal structure, indicating conformational transitions occurring at 4 GPa.