Study of metal-carboxylate complex from Pinus elliottii resin applied as antibacterial pigment

Metal carboxylate complexes derived from Pinus elliottii resin have been reported as promising pigments for paints and coatings due to their high antibacterial, antifungal, and antiviral properties. Besides the antibacterial and/or antiviral properties of the pigments, color, and stability are essential characteristics often associated with the oxidation state of the coordinating metal atom, such as Mn, Fe, Co, Ni, or Cu. However, using traditional analysis techniques, the low metal concentration in the pigment makes it challenging to determine the metal oxidation state and the electronic structure of the metal complex used as pigments. To this aim, we use nanoscale NEXAFS recorded at the XM-beamline (U41-PGM1-XM) at BESSY II to investigate the local electronic structure surrounding a selected elemental species its oxidation state. The design of the X-ray Microscopy Beamline U41-PGM1-XM enables analysis in the soft (0.25 keV 1.5 keV) and tender X-ray photon energy regime (1 keV-2.7 keV), allowing the study via Near Edge X-ray Absorption Fine Structure of different metal carboxylate complexes used as pigments.