Aftermath of irradiation: the stacking faults in crystal of giant supramolecule unexpectedly mended before total decay

As often observed for supramolecules, a crystal of a Ta-based peanut-shaped supramolecule [{Cp '' Ta(CO)(2)(eta(4)-P-4)}(10)(CuI)(14)] (1) decays under X-rays. Unexpectedly, a solid-to-solid transformation evidenced by a unit cell change took place on irradiation prior to the complete decay. This unusual behaviour was studied with the same single crystal of 1. According to the results of the structure refinement interpreted using OD theory, crystals of 1 continuously change their macro-structure which is accompanied by an increase of space group symmetry and by vanishing of crystallographic disorder.