Model for photoinduced bending of slender molecular crystals.

The growing realization that photoinduced bending of slender photoreactive single crystals is surprisingly common has inspired researchers to control crystal motility for actuation. However, new mechanically responsive crystals are reported at a greater rate than their quantitative photophysical characterization; a quantitative identification of measurable parameters and molecular-scale factors that determine the mechanical response has yet to be established. Herein, a simple mathematical description of the quasi-static and time-dependent photoinduced bending of macroscopic single crystals is provided. This kinetic model goes beyond the approximate treatment of a bending crystal as a simple composite bilayer. It includes alternative pathways for excited-state decay and provides a more accurate description of the bending by accounting for the spatial gradient in the product/reactant ratio. A new crystal form (space group P21/n) of the photoresponsive azo-dye Disperse Red 1 (DR1) is analyzed within the constraints of the aforementioned model. The crystal bending kinetics depends on intrinsic factors (crystal size) and external factors (excitation time, direction, and intensity).

[1]  H. Finkelmann,et al.  A new opto-mechanical effect in solids. , 2001, Physical review letters.

[2]  Thomas A. Singleton,et al.  Fast, Reversible, and General Photomechanical Motion in Single Crystals of Various Azo Compounds Using Visible Light , 2013, Advanced materials.

[3]  L Mahadevan,et al.  Photoinduced deformations of beams, plates, and films. , 2004, Physical review letters.

[4]  M. Warner,et al.  Nonlinear photoresponse of disordered elastomers. , 2006, Physical review letters.

[5]  C. Pierpont.  Bending crystals. Solid state photomechanical properties of transition metal complexes containing semiquinonate ligands , 2002 .

[6]  R. Jay Conant,et al.  Advanced Mechanics of Materials , 2003 .

[7]  H. Benaroya,et al.  DYNAMICS OF TRANSVERSELY VIBRATING BEAMS USING FOUR ENGINEERING THEORIES , 1999 .

[8]  H. Koshima,et al.  Photomechanical Motion of Furylfulgide Crystals , 2012 .

[9]  B. Feringa,et al.  Photoresponsive rolling and bending of thin crystals of chiral diarylethenes. , 2008, Chemical communications.

[10]  C. M. Reddy,et al.  Elastic and bendable caffeine cocrystals: implications for the design of flexible organic materials. , 2012, Angewandte Chemie.

[11]  K. Houk,et al.  The photoarrangement of alpha-santonin is a single-crystal-to-single-crystal reaction: a long kept secret in solid-state organic chemistry revealed. , 2007, Journal of the American Chemical Society.

[12]  I. Ritchie,et al.  On Timoshenko's correction for shear in vibrating isotropic beams , 1977 .

[13]  S. Timoshenko,et al.  Analysis of Bi-Metal Thermostats , 1925 .

[14]  C. Bardeen,et al.  Using two-photon excitation to control bending motions in molecular-crystal nanorods. , 2009, Small.

[15]  M. Irie,et al.  Light-driven molecular-crystal actuators: rapid and reversible bending of rodlike mixed crystals of diarylethene derivatives. , 2012, Angewandte Chemie.

[16]  R. Al‐Kaysi,et al.  Photoinduced curling of organic molecular crystal nanowires. , 2013, Angewandte Chemie.

[17]  Masahiro Irie,et al.  A diarylethene cocrystal that converts light into mechanical work. , 2010, Journal of the American Chemical Society.

[18]  Tomoyuki Ishikawa,et al.  Rapid and reversible shape changes of molecular crystals on photoirradiation , 2007, Nature.

[19]  H. Koshima,et al.  Mechanical motion of azobenzene crystals upon photoirradiation. , 2009, Journal of the American Chemical Society.

[20]  C. M. Reddy,et al.  Mechanical properties of molecular crystals—applications to crystal engineering , 2010 .

[21]  T. W. Clyne,et al.  Residual Stresses in Thermal Spray Coatings and Their Effect on Interfacial Adhesion: A Review of Recent Work , 1996 .

[22]  L. J. Mueller,et al.  Dependence of the solid-state photomechanical response of 4-chlorocinnamic acid on crystal shape and size , 2012 .

[23]  H. Koshima,et al.  Photomechanical bending of 4-aminoazobenzene crystals , 2012 .

[24]  Christopher J. Bardeen,et al.  Reversible Photoinduced Shape Changes of Crystalline Organic Nanorods , 2007 .

[25]  M. Irie,et al.  Photochromism of diarylethene single crystals: crystal structures and photochromic performance. , 2005, Chemical communications.

[26]  B. Kahr,et al.  Reversible twisting during helical hippuric acid crystal growth. , 2010, Journal of the American Chemical Society.

[27]  R. Al‐Kaysi,et al.  Reversible photoinduced twisting of molecular crystal microribbons. , 2011, Journal of the American Chemical Society.

[28]  Lacroix,et al.  Azo-azulene derivatives as second-order nonlinear optical chromophores , 2000, Chemistry.

[29]  Martin L. Dunn,et al.  Photomechanics of mono- and polydomain liquid crystal elastomer films , 2007 .

[30]  P. Naumov,et al.  Topochemistry and photomechanical effects in crystals of green fluorescent protein-like chromophores: effects of hydrogen bonding and crystal packing. , 2010, Journal of the American Chemical Society.

[31]  P. Naumov,et al.  Dynamic single crystals: kinematic analysis of photoinduced crystal jumping (the photosalient effect). , 2013, Angewandte Chemie.

[32]  D. Hashizume,et al.  Photomechanical bending of salicylideneaniline crystals. , 2011, Chemical communications.

[33]  R. Al‐Kaysi,et al.  Photochemically driven shape changes of crystalline organic nanorods. , 2006, Journal of the American Chemical Society.

[34]  M. Irie,et al.  Diarylethene microcrystals make directional jumps upon ultraviolet irradiation. , 2007, The Journal of chemical physics.