TY - JOUR
T1 - Luminescence Mechanochromism Induced by Cluster Isomerization
AU - Huitorel, Brendan
AU - El Moll, Hani
AU - Cordier, Marie
AU - Fargues, Alexandre
AU - Garcia, Alain
AU - Massuyeau, Florian
AU - Martineau-Corcos, Charlotte
AU - Gacoin, Thierry
AU - Perruchas, Sandrine
N1 - Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/10/16
Y1 - 2017/10/16
N2 - Luminescent mechanochromic materials exhibiting reversible changes of their emissive properties in response to external mechanical forces are currently emerging as an important class of stimuli-responsive materials because of promising technological applications. Here, we report on the luminescence mechanochromic properties of a [Cu4I4(PPh3)4] copper iodide cluster presenting a chair geometry, being an isomer of the most common cubane form. This molecular cluster formulated [Cu4I4(PPh3)4]·2CHCl3 (1) exhibits a highly contrasted emission response to manual grinding, and, interestingly, the optical properties of the ground phase present striking similarities with those of the cubane isomer. In order to understand the underlying mechanism, a comparison with two related compounds has been conducted. The first one is a pseudopolymorph of 1 formulated as [Cu4I4(PPh3)4]·CH2Cl2 (2), which exhibits luminescent mechanochromic properties as well. The other one is also a chair compound but with a slightly different phosphine ligand, namely, [Cu4I4(PPh2C6H4CO2H)4] (3), lacking mechanochromic properties. Structural and optical characterizations of the clusters have been analyzed in light of previous electronic structure calculations. The results suggest an unpreceded mechanochromism phenomenon based on a solid-state chair → cubane isomer conversion. This study shows that polynuclear copper iodide compounds are particularly relevant for the development of luminescent mechanochromic materials.
AB - Luminescent mechanochromic materials exhibiting reversible changes of their emissive properties in response to external mechanical forces are currently emerging as an important class of stimuli-responsive materials because of promising technological applications. Here, we report on the luminescence mechanochromic properties of a [Cu4I4(PPh3)4] copper iodide cluster presenting a chair geometry, being an isomer of the most common cubane form. This molecular cluster formulated [Cu4I4(PPh3)4]·2CHCl3 (1) exhibits a highly contrasted emission response to manual grinding, and, interestingly, the optical properties of the ground phase present striking similarities with those of the cubane isomer. In order to understand the underlying mechanism, a comparison with two related compounds has been conducted. The first one is a pseudopolymorph of 1 formulated as [Cu4I4(PPh3)4]·CH2Cl2 (2), which exhibits luminescent mechanochromic properties as well. The other one is also a chair compound but with a slightly different phosphine ligand, namely, [Cu4I4(PPh2C6H4CO2H)4] (3), lacking mechanochromic properties. Structural and optical characterizations of the clusters have been analyzed in light of previous electronic structure calculations. The results suggest an unpreceded mechanochromism phenomenon based on a solid-state chair → cubane isomer conversion. This study shows that polynuclear copper iodide compounds are particularly relevant for the development of luminescent mechanochromic materials.
U2 - 10.1021/acs.inorgchem.7b01870
DO - 10.1021/acs.inorgchem.7b01870
M3 - Article
C2 - 28949130
AN - SCOPUS:85031753502
SN - 0020-1669
VL - 56
SP - 12379
EP - 12388
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 20
ER -