02198nas a2200181   4500008004100000022001400041245011000055210006900165260000800234300001400242490000700256520153600263100001901799700002001818700002601838700002101864856013101885       2025                        eng d  a1528-748300aMechanical flexibility, photosalience, and acidochromism of benzylidene indanone-based molecular crystals0 aMechanical flexibility photosalience and acidochromism of benzyl  cJUN  a4481-44930 v253 a<p>
	Molecular crystals that respond to multiple external stimuli are of great interest in smart, responsive materials in various fields. However, the integration of multiple responsive properties within the same crystal still remains a significant challenge for materials scientists due to the complex structural and electronic interactions. Previous studies on benzylidene indanone-based molecular crystals have shown only mechanical plasticity; however, we design crystals to elicit diverse responses to external stimuli, including mechanical stress, light, and acid vapor. Herein, we report two benzylidene indanone derivative-based crystals 1 and 2. Crystal 1 is mechanically brittle and exhibits light-induced photosalient splitting and jumping, attributed to [2 + 2] cycloaddition facilitated by the presence of a vinyl moiety. On the other hand, crystal 2 demonstrates anisotropic mechanical flexibility, exhibiting elasticity on one face and plasticity on alternate faces. Furthermore, crystals 1 and 2 both display reversible acidochromism in response to acid vapor. A detailed structure-property correlation has been established to elucidate the distinct mechanical responses of these molecular crystals. The development of such multistimuli-responsive smart materials holds significant potential for applications in flexible acid sensors, multifunctional responsive smart devices, and actuators, paving the way for advanced smart or intelligent molecular materials with tunable mechanical and optical properties.</p>
1 aAhamed, Riyaaz1 aBhowmik, Aritra1 aMishra, Manish, Kumar1 aGhosh, Soumyajit  uhttps://library.ncl.res.in/content/mechanical-flexibility-photosalience-and-acidochromism-benzylidene-indanone-based-molecular