Thermomechanical effect in molecular crystals: the role of halogen-bonding interactions

Mittapalli, Sudhir; Perumalla, D. Sravanakumar; Nanubolu, Jagadeesh Babu; Nangia, Ashwini

doi:10.1107/s2052252517014658

Cited by 16 publications

(13 citation statements)

References 53 publications

(55 reference statements)

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“…Overall, the densities were found to decrease after photoreaction (14.7% for 1 to 4, 15.6% for 2 to 5 and 12.2% for 3 to 6) and these correspond to the increase in unit cell volumes of 15.4, 17.5 and 13.1% on going from 1-3 to 4-6, respectively ( Table S2). The mobility of dynamic single crystals is usually triggered by the sudden release of stress in the form of a very fast phase transition or a chemical reaction accompanied a rapid structural change that drives these phenomena (Nath et al, 2014;Chizhik et al, 2018;Ghosh et al, 2015;Sahoo et al, 2014Sahoo et al, , 2013aSkoko et al, 2010;Rawat et al, 2018;Panda et al, 2015Panda et al, , 2016Boldyreva, 1994;Mittapalli et al, 2017). Here, the stress created by the phase heterometry due to the difference in the unit cell volumes and the release of that stress manifests as motion or explosive fragmentation of the crystals.…”

Section: Resultsmentioning

confidence: 99%

Extraordinary anisotropic thermal expansion in photosalient crystals

Yadava

Gallo

Bette

et al. 2020

IUCrJ

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Although a plethora of metal complexes have been characterized, those having multifunctional properties are very rare. This article reports three isotypical complexes, namely [Cu(benzoate)L 2], where L = 4-styrylpyridine (4spy) (1), 2′-fluoro-4-styrylpyridine (2F-4spy) (2) and 3′-fluoro-4-styrylpyridine (3F-4spy) (3), which show photosalient behavior (photoinduced crystal mobility) while they undergo [2+2] cycloaddition. These crystals also exhibit anisotropic thermal expansion when heated from room temperature to 200°C. The overall thermal expansion of the crystals is impressive, with the largest volumetric thermal expansion coefficients for 1, 2 and 3 of 241.8, 233.1 and 285.7 × 10−6 K−1, respectively, values that are comparable to only a handful of other reported materials known to undergo colossal thermal expansion. As a result of the expansion, their single crystals occasionally move by rolling. Altogether, these materials exhibit unusual and hitherto untapped solid-state properties.

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Section: Resultsmentioning

confidence: 99%

Extraordinary anisotropic thermal expansion in photosalient crystals

Yadava

Gallo

Bette

et al. 2020

IUCrJ

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“…The effect was first noted in 1983, and after a long hiatus, it was explored in greater detail in the anticholinergic agent oxitropium bromide in 2010 . Encouraged by these studies, over 20 new examples have been reported in the last decade that are categorized in three classes based on their structures, with a number of notable reports of serendipitous observations increasing in the past several years . It has also been demonstrated that the rates of the TS phase transitions are several orders of magnitude faster than other, more common solid–solid transitions .…”

Section: Introductionmentioning

confidence: 99%

Global Performance Indices for Dynamic Crystals as Organic Thermal Actuators

Karothu

Halabi

et al. 2020

Advanced Materials

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same basic thermodynamic principles of energy transduction and are collectively referred to as actuators. [1][2][3][4][5][6][7][8][9][10] While complex natural biomechanical systems have evolved to aid functions such as dispersal and survival, the artificially manufactured actuators are specifically designed for integration in mechatronic or adaptronic systems that range from miniature devices such as navigation and positioning systems in flying machines, to complex systems that can perform tasks in specific environments, such as humanoid robots and spacecraft. The current applications of actuators are many and diverse; they include sensors, [11,12] artificial muscles, [13] soft robotics, [14] and energy-harvesting materials. [15] Simple or complex actuating motions can be induced by heat, light, electricity, pressure, and moisture, among other stimuli, and can be realized with shape-memory polymers, [16] conductive fibers, [17] liquid crystal elastomers, [18] piezoelectric, [19] magnetostrictive, [20] and electromagnetic materials. [21] The energy supplied to the artificial actuators can vary from fluid pressure or flow in the pneumatics, to current, charge or voltage in the electromagnetic, piezoelectric and magnetostrictive actuators, to heat in shape memory and thermal expansion actuators.The active media in actuators include fluids, hard solids such as metals, and even complex soft matter such as tissuesensembles of cells with similar structure that act together to perform a specific function. While molecular crystals do not immediately appeal as working actuating medium, their dynamic properties have recently transpired as an alternative to other materials and they are thought to hold an untapped potential for miniature, soft actuating devices, quickly shaping up into a new research field, crystal adaptronics. [22,23] Smallscale demonstrations of the usefulness of molecular crystals as microscale devices, including cantilevers, [24,25] ratchets, [26] optical waveguides, [27][28][29][30][31][32][33][34][35][36] and other "crystal gears" [37] that can move or reshape are occasionally reported for dynamic crystals. Although being very illustrative, these demonstrations have thus far remained limited to a laboratory scale and have not been implemented in actual, functional devices. Some of the obstacles toward wider applications are difficulties with reproducible growth of crystals of predictable size without the use Crystal adaptronics is an emergent materials science discipline at the intersection of solid-state chemistry and mechanical engineering that explores the dynamic nature of mechanically reconfigurable, motile, and explosive crystals. Adaptive molecular crystals bring to materials science a qualitatively new set of properties that associate long-range structural order with softness and mechanical compliance. However, the full potential of this class of materials remains underexplored and they have not been considered as materials of choice in an engineer's toolbox. A set of general performance metric...

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“…31 Recently, Mittapalli et al reported halogen-substituted Nsalicylideneaniline derivatives with a thermosalient effect. 32,33 Among the five compounds reported in their paper, one compound exhibited a thermosalient effect with a change of space group, unlike the existing compounds showing a thermosalient effect. Form Ⅰ of this compound, which was crystallised in the monoclinic space group P2 1 /c, changed into form Ⅱ, which belonged to the triclinic space group P1 � , with cracking upon heating.…”

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confidence: 97%

“…This is a rare example of the reported thermosalient effect because this effect has been generally considered to originate from a significant anisotropic lattice change without any changes in crystal system and space group. 32 During our polymorph hunting on a N,N′-bispropylated diketopyrrolo dye [3,6-…”

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confidence: 99%