Rapid, Robust, and Reversible Photomechanical Bending in a Flexible Zinc(II) Complex Crystal with 2D Elasticity for Controlled Motion.

The integration of rapid, reversible photomechanical responsiveness and 2D elasticity within a single coordination crystal remains a formidable challenge. Here, we report a Zn(II) coordination complex, [Zn(NCS)2(Z-fppan)2] (Z-1, Z-fppan = (Z)-2-(3-fluorophenyl)-3-(pyridin-4-yl)acrylonitrile), where the synergy between photochemical isomerization and photothermal-induced temperature gradients enables millisecond-scale response. Driven by this dual mechanism, the crystal demonstrates robust and reversible photoinduced bending (>100 cycles). The generation of these localized stress gradients enables precise control over diverse photoactuated motions, including bending, rolling, and deflection. Additionally, single crystals of Z-1 exhibit remarkable two-dimensional elastic flexibility under mechanical stress, deforming reversibly along the (110)/(-1-10) and (-110)/(1-10) planes. The combination of rapid photomechanical actuation and mechanical adaptability presents a unique example of dual-stimulus responsive behavior in metal-organic systems. To demonstrate this practical utility, we leveraged this photomechanical behavior for wireless manipulation, successfully achieving remote-controlled actuation. Such properties position Z-1 as a promising candidate for light-driven smart actuators and soft robotics.