Mechanically responsive luminescent films based on copper iodide clusters

Abstract

A mechanochromic luminescent copper iodide cluster is reported whose luminescence is exalted in response to mechanical stress. The underlying mechanism has been investigated along with the preparation of mechanically responsive films.

A Cu2I2-Based Coordination Framework as the Selective Sensor for Ag+ and the Effective Adsorbent for I2

“…To construct these promising MOF-based sensors or adsorbents, the employment of metal-based clusters as secondary building units (SBUs) is considered to be an effective way for the acquisition of desirable products. − By virtue of the tailorable compositions and tunable sizes in SBUs, diverse structural forms and plenty types of electronic transfers could be realized in the resultant coordination compounds. Copper-iodide clusters with a series of geometrically units, such as the [Cu 2 I 2 ] rhomboid unit, [Cu 4 I 4 ] cubane-like tetramer, [Cu 6 I 6 ] hexagonal-prism-shaped moiety, [Cu x I y ] n zigzag chains, and other intricate polyhedra, have emerged as the excellent building blocks for the assembly of luminescent materials with permanent porosities. , Especially, the internal band energy of the copper iodide components could be influenced by many factors, including the temperature, guest species, solvents, and mechanical force; thus, the optical behaviors of the corresponding MOFs are apt to be altered with a structural difference or an external stimulus. − For example, two isomorphic Cu 3 I 3 -based organic frameworks were fabricated by Hong’s group, wherein distinct guest solvents resulted in an entirely different fluorescence performance . Our group previously reported a Cu 2 I 2 -containing heterometallic-organic framework, whose luminescence behavior largely depended on the existence of iron ions .…”

Thermo-, Mechano-, and Vapochromic Dinuclear Cuprous-Emissive Complexes with a Switchable CH3CN–Cu Bond

“…Stimuli-responsive luminescent materials, especially those with high-contrast luminescence colors that are reversibly convertible to each other, have received considerable interest for their potential applications in optical sensor, data recording, bioimaging, and security system. − However, the dual- and multiple-stimuli-responsive systems, particularly those with multicolor luminescence, are quite limited relative to the single-stimulus responsive ones. − Stimuli-responsive luminescent materials based on metal complexes have become a research hotspot in recent years due to their advantages of easy modification of organic compounds and stability of inorganic compounds. − Most of them are the platinum-, gold-, silver-, and other precious-metal-based complexes. − Some copper- and zinc-based complexes also show good stimuli-responsive luminescence properties. − Cuprous complexes are attractive for developing low-cost stimuli-responsive luminescent materials because of their good luminescent properties and diverse structures and abundant Cu element. − However, it remains a challenge to precisely design multi-stimuli-responsive cuprous-emissive complexes that are easily synthesized and exhibit switchable multicolor luminescence.…”

Impact of Intermolecular Non‐Covalent Interactions in a CuI8PdII1 Discrete Assembly: Conformers’ Geometries and Stimuli‐Sensitive Luminescence Properties

“…This phenomenon was previously reported by Perruchas et al investigating the mechanochromic behavior of Cu 4 I 4 cubane clusters stabilized by phosphane ligands. [12] It was assigned to an effect of the mechanical stress application on the crystallite sizes and/or generation of microstrains which induces local apparition in a bulk composite sample of a small Chemistry-A European Journal amount of a new generated amorphous emissive domains in addition to the original pristine crystalline phase. SEM pictures (Figure 6) recorded for B o and B g support this assumption since significantly similar patterns were observed in both cases revealing polycrystalline particles having quite a large size distribution with smaller average dimensions for B g samples likely as a result of the grinding process.…”