In this section
@article{Li:2026:10.1021/acs.cgd.6c00690,
author = {Li, X and Xu, L and He, F and Xie, Z and Zhou, L and Heng, J and Ouyang, J},
doi = {10.1021/acs.cgd.6c00690},
journal = {Crystal Growth and Design},
pages = {5242--5251},
title = {Precise Control of Photomechanical Response Modes of Barbituric Acid Derivative Crystals: from Bending to Fragmentation},
url = {http://dx.doi.org/10.1021/acs.cgd.6c00690},
volume = {26},
year = {2026}
}
TY - JOUR
AB - Photomechanically responsive crystals show significant application potential in fields such as flexible optoelectronic devices, micro/nano manipulation, and smart biomimetic materials. However, how to precisely control the photomechanical response modes of crystals (such as bending and fracturing) through molecular design, remains a major challenge in this field. This paper reports four novel barbituric acid derivative crystals (BTBA, DBH-DMB, DCMP, and DCB-TP), which exhibit distinct photoinduced bending and photoinduced fracturing behaviors upon light excitation. Calculations of single-crystal structures, Hirshfeld surfaces, and energy frameworks indicate that BTBA and DBH-DMB, which have smaller molecular dihedral angles, possess two-dimensional layered sliding structures formed by strong π–π stacking. The internal stress generated by photoexcitation can be dissipated through the ordered sliding of molecular layers, thereby exhibiting photoinduced bending behavior; in contrast, DCMP and DCB-TP, which have nearly perpendicular molecular dihedral angles, exhibit larger steric hindrance that impedes π–π stacking and lacks sliding interfaces; internal stress accumulates rapidly at defects, ultimately leading to crystal fragmentation. Notably, the bending behavior of BTBA is partially thermally reversible, whereas that of DBH-DMB is irreversible. Size effects indicate that longer and thinner crystals exhibit lower bending stiffness and superior tip deflection performance. Molecular orbital energy levels further reveal that bending crystals possess moderate energy gaps and significant intramolecular charge transfer characteristics, which are conducive to the formation of oriented stress gradients; in contrast, fracturing crystals have larger energy gaps, higher degrees of electronic localization, and greater structural rigidity. This study uncovers the synergistic regulatory mechanisms by which molecular conformation, stacking patterns, and elec
AU - Li,X
AU - Xu,L
AU - He,F
AU - Xie,Z
AU - Zhou,L
AU - Heng,J
AU - Ouyang,J
DO - 10.1021/acs.cgd.6c00690
EP - 5251
PY - 2026///
SN - 1528-7483
SP - 5242
TI - Precise Control of Photomechanical Response Modes of Barbituric Acid Derivative Crystals: from Bending to Fragmentation
T2 - Crystal Growth and Design
UR - http://dx.doi.org/10.1021/acs.cgd.6c00690
VL - 26
ER -