Formation of an Unstable Photodimer from 9-Anthracenecarboxylic Acid in the Solid State

Ito, Yoshikatsu; Fujita, Haruo

doi:10.1021/jo960486v

Cited by 46 publications

(41 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…New peaks appearing at around 5.6 and 6.7 ppm were identified as those of the head-to-tail A-COOH photodimer, while peaks of the head-to-head photodimer at 4.6 and 7.4 ppm were not observed (Figures 3b and S6, SI). 18 This result indicates that the head-to-tail photodimer D-2COOH was formed in the IL [1-H] + [A-COO] ¹ , which successively phase-separated to form the crystalline phase. IR measurements of the photoirradiated neat mixture revealed a peak at 1674 cm ¹1 , assignable to¯(C=O) of the hydrogen-bonded COOH group (Figure 3c).…”

mentioning

confidence: 95%

Photoinduced Crystallization in Ionic Liquids: Photodimerization-induced Equilibrium Shift and Crystal Patterning

Hisamitsu

Yanai²,

Fujikawa³

et al. 2015

Chemistry Letters

View full text Add to dashboard Cite

An ionic liquid (IL) composed of 9-anthracenecarboxylate anion and ammonium cation possessing three diethylene glycol chains shows phototriggered dimerization of anthracence chromophores. It causes segregation and crystallization of protonated 9-anthracenecarboxylic acid dimer, which is associated with the concurrent liberation of the free amine in the IL. This work provides a new molecular design for photoresponsive ILs, whose first application for site-selective photopatterning is demonstrated.Ionic liquids (ILs) have attracted considerable interest from many researchers because of their unique physical and chemical properties, which are tunable depending on their constituents. 13One of the evolving areas in this field is the introduction of mesoscopic interfaces 4,5 for developing novel interfacial phenomena. 6,7 In this regard, ILs containing π-conjugated chromophores are attractive as photofunctional soft materials that show new applications such as condensed luminescent materials 810 and solar thermal storage. 11 We have recently reported the photoliquefaction of ionic crystals to ILs by employing cationic azobenzene derivatives covalently modified with three flexible diethylene glycol chains in the ammonium head group. 11 Photon energy was effectively stored not only as the conformational energy of the azobenzene unit but also as the latent heat of crystallization, where the integration of self-assembly phenomena and photoresponsive ILs opened the doors to the phase crossover chemistry. 11Here, we describe a new photoresponsive IL that shows photoinduced crystallization phenomena. It is formed from a well-known Brønsted acid (9-anthracenecarboxylic acid, A-COOH) 12,13 and a Brønsted base having three flexible diethylene glycol chains (tris[2(2methoxyethoxy)ethyl]amine, 1). This integration based on acidbase neutralization gives a chromophoric IL [1-H] +

show abstract

mentioning

confidence: 95%

Photoinduced Crystallization in Ionic Liquids: Photodimerization-induced Equilibrium Shift and Crystal Patterning

Hisamitsu

Yanai²,

Fujikawa³

et al. 2015

Chemistry Letters

View full text Add to dashboard Cite

show abstract

“…We have confirmed the reversible nature of the solid-state photodimerization in our samples by monitoring the decrease and subsequent recovery of the monomer crystal fluorescence, which peaks at 505 nm in both nanorods and other crystal types. Although solid state NMR data has confirmed the molecular structure of the photodimer, [22] it does not provide information on changes in the crystal structure or unit cell dimensions. Unfortunately, attempts to obtain the crystal structure of the photodimer were unsuccessful.…”

mentioning

confidence: 99%

“…1c, inset). Although the cis arrangement is often assumed to prevent the [4+4] cycloaddition reaction in the solid state due to "topochemical" factors, [21] solid state NMR measurements [22] showed that 9-AC does in fact undergo the [4+4] cycloaddition reaction characteristic of anthracenes in the solid state ( Fig. 1d).…”

mentioning

confidence: 99%

“…The aqueous rods show a much greater degree of reversibility than the polycrystalline films studied previously, where the monomer fluorescence only recovered to 30 % of its original value after irradiation. [22] Extrapolation of this curve leads to an estimate of the half-life of the rods of approximately 12 cycles for 15 s illumination periods, and more than 30 cycles for 5 s illumination periods. It is likely that this could be improved by more rigorous exclusion of O 2 from the sample.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Reversible Photoinduced Shape Changes of Crystalline Organic Nanorods

2007

View full text Add to dashboard Cite

Mechanical devices that function on sub-micrometer length scales are expected to find applications in fields ranging from medicine to manufacturing. Biology provides many examples of nanoscale machines, for example, the adenosine triphosphate (ATP)-fueled motion of myosin along the actin filament. [1] In such systems, the motion is fueled by random encounters with high-energy chemical species in the surrounding medium and occurs stochastically, because there is no way to externally control diffusive encounters at the molecular level. An alternative is to use external energy sources (e.g., photons) to activate motion at the nanoscale. Photochemically powered mechanical motion is attractive because it does not require the presence of a second chemical species and external control of the motion can be achieved by manipulating the illumination conditions. These advantages have propelled research into photoactivated mechanical motion on the molecular level, and there have been many examples of photoactivated molecular switching, translation, and geometrical transformations. [2][3][4] In general, these schemes rely on intramolecular events-bond formation, cyclization, cis-trans isomerization-to drive a structural change on the order of 1 Å or less. This molecular-level change can be amplified by coupling multiple molecules together using a liquid-crystal polymeric host. Recent progress in the development of photodeformable polymer fibers and strips has led to micrometer-scale materials that exhibit light-induced shape memory effects, [5,6] reversible bending under anisotropic illumination conditions, [7][8][9][10][11][12][13] and photocontrol of the crosslink density. [14] Recently, we demonstrated the use of an intermolecular photochemical reaction to achieve large physical displacements in a different type of structure: organic molecular crystal nanorods.[15] By taking advantage of the well-known anthracene [4+4] photocycloaddition reaction in 9-tertbutyl-anthracene ester (9-TBAE) molecular crystal nanorods, a large (15 %) change in rod length could be generated. In most cases, the photochemical changes drive a reconstructive crystal-to-crystal phase transition that leads to crystal fragmentation and disintegration. [16][17][18] Apparently, the high surface-to-volume ratio of the nanorods provides sufficient strain relief to avoid cracking and fragmentation during this transition. Although the expansion of the 9-TBAE rods was ca. 100 times larger than that observed in other photoisomerizable molecular crystals, [19] it was largely irreversible. If a reversible system could be found, significant amounts of useful work could be generated by repeatedly inducing such mechanical motion. In the following, we demonstrate that molecular crystal nanorods composed of a related molecule, 9-anthracene carboxylic acid (9-AC), can undergo reversible photoinduced cycling between well-defined shapes after spatially localized excitation. The kinetics of recovery, its dependence on illumination conditions, and the long-term stability ...

show abstract

“…The nanoscale dimensions of rods composed of these anthracene derivatives permit them to undergo crystal‐to‐crystal photoreactions that would cause a macroscopic crystal to disintegrate 18, 19. In the case of 9‐anthracene carboxylic acid (9AC), the photodimer spontaneously dissociates within a few minutes, resetting the system 20…”

Section: Introductionmentioning

confidence: 99%

Using Two‐Photon Excitation to Control Bending Motions in Molecular‐Crystal Nanorods

Good

Burdett

Bardeen

2009

Small

View full text Add to dashboard Cite

Molecular-crystal nanorods composed of 9-anthracenecarboxylic acid can undergo reversible bending due to molecular-level geometry changes associated with the photodimerization of the molecules in the crystal lattice. The use of highly focused near-IR femtosecond laser pulses results in two-photon excitation of micrometer-scale regions and is used to induce transient bends at various locations along the length of a single 200-nm-diameter nanorod. Bending can be observed in nanorods with diameters as small as 35 nm, and translational motion of a single nanorod could be induced by sequential bending of longer segments. A kinetic model is presented that quantitatively describes the bending and relaxation dynamics of individual rods. The results of this work show that it is possible to use laser excitation conditions to control the location, rate, and magnitude of photodeformations in these nanorods. The ability to control the motion of these ultrasmall photomechanical structures may be useful for manipulating objects on the nanoscale.

show abstract

Formation of an Unstable Photodimer from 9-Anthracenecarboxylic Acid in the Solid State

Cited by 46 publications

References 9 publications

Photoinduced Crystallization in Ionic Liquids: Photodimerization-induced Equilibrium Shift and Crystal Patterning

Photoinduced Crystallization in Ionic Liquids: Photodimerization-induced Equilibrium Shift and Crystal Patterning

Reversible Photoinduced Shape Changes of Crystalline Organic Nanorods

Using Two‐Photon Excitation to Control Bending Motions in Molecular‐Crystal Nanorods

Contact Info

Product

Resources

About