Stress to distress: Triboluminescence and pressure luminescence of lanthanide diketonates

•Mechano-optics such as tribo/high-pressure luminescence is useful in stress sensing.•First to explore the possibility of lanthanide complexes as stress sensors.•A new family of halogen EuIII diketonate complexes with unique optics is examined.•Shows influence of crystal packing/high-pressure compression on triboluminescence.•Diamond anvil cell show material compression induces phase transition/peak shifting.