• Costuas, Karine
• Khalil, Ali Moustafa
• Delmas, Vincent
• Schiller, Jana
• Moutier, Florent
• Lecourt, Constance
• Calvez, Guillaume
• Lescop, Christophe

Abstract

International audience ; A new highly solid-state luminescent phase of a previously reported weakly luminescent Cu I 8 Pd II 1 dicationic assembly is reported revealing the high geometrical versatility of this moiety that importantly alters its luminescent properties. This very minor new species B c is based on a different conformer scaffold than the one encountered in the previously reported B o form and, essentially differs from B o by displaying shorter Cu I -Cu I intermetallic distances. DFT calculations allow concluding that the predominance in the solid-state of the weakly luminescent and less stable B o phase is due to the extra stability induced by a larger number of intermolecular non-covalent π-CH interactions in its crystalline packing and not by the intrinsic stability of the Cu I 8 Pd II 1 dicationic moiety. Calculations also revealed that a more stable conformation B calc is expected in vacuum, which bears a different distribution of Cu I -Cu I intermetallic distances than the dications in B o and B c phases. Taking into account that the geometrical alterations are associated to drastic changes of luminescence properties, this confer to the Cu I 8 Pd II 1 assembly high potentiality as stimuli-sensitive luminescent materials. Indeed, by applying mechanical or thermal stress to samples of B o phase, new phases B g and B m , respectively, were obtained. Alterations of the solid-state photophysical properties of these new species compared to those recorded for B o are reported together with a combined experimental and computed study of the structures/properties relationships observed in these phases.

Topics

• impedance spectroscopy
• phase
• laser emission spectroscopy
• density functional theory
• intermetallic
• luminescence