Thulium(III) 2,4-pentanedionate is primarily used in the field of materials science, particularly in the deposition of thin films. It serves as a precursor in chemical vapor deposition (CVD) and atomic layer deposition (ALD) processes to create high-quality thulium oxide films. These films are essential in the production of advanced optical materials, including specialized coatings for lenses and mirrors that require precise control over refractive properties. Additionally, it is employed in the development of luminescent materials, where thulium's unique emission characteristics are utilized in applications such as phosphors for lighting and display technologies. Its role in catalysis is also noteworthy, particularly in organic synthesis reactions where it can act as a Lewis acid to facilitate specific transformations.