Dynamische Kristalle: visuell wahrnehmbare mechanochemische Lumineszenzänderungen von Gold‐ und anderen Übergangsmetallkomplexen

Balch, Alan L.

doi:10.1002/ange.200805602

“…To induce change in the luminescent colors of organic and organometallic materials, one could switch the molecularly assembled structures 4–7. Crystals,8–24 liquid crystals,25–28 and polymers29–32 have been reported to change their luminescent colors by mechanical and thermal stimuli. The observed phenomena are referred to as piezo(mechano)chromic or thermochromic luminescence.…”

Section: Methodsmentioning

confidence: 99%

Brightly Tricolored Mechanochromic Luminescence from a Single‐Luminophore Liquid Crystal: Reversible Writing and Erasing of Images

Sagara,

Kato

2011

View full text Add to dashboard Cite

Luminescent materials that switch their photoluminescent properties in response to various external stimuli have attracted much attention for a decade because of their potential application for memory devices, sensors, security materials, and informational displays. [1][2][3][4][5] To induce change in the luminescent colors of organic and organometallic materials, one could switch the molecularly assembled structures. [4][5][6][7] Crystals, [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] liquid crystals, [25][26][27][28] and polymers [29][30][31][32] have been reported to change their luminescent colors by mechanical and thermal stimuli. The observed phenomena are referred to as piezo(mechano)chromic or thermochromic luminescence. Such materials contain just one type of luminophore and they form only two luminescent states. In the condensed states, to date, multiemission colors that are generated from a single luminophore and switch between their colors using external stimuli have not been achieved for organic and organometallic materials; the one exception is a crystalline compound. [16] If such materials are prepared using liquid crystals, it leads to new applications of stimuli-responsive luminescent materials that are flexible, sophisticated, and highly functional.Liquid crystals are functional soft materials that exhibit mobile and ordered states.[33] Because of their dynamic properties, liquid crystals are good candidates for stimuliresponsive luminescent materials. [25][26][27][28] In our previous studies, we have prepared pyrene-, anthracene-, and naphthalenebased liquid crystals that show piezo(mechano)chromic luminescence and thermochromic luminescence in liquidcrystalline (LC) states. [25,26] However, multiluminescent colors have not been achieved for these LC materials.Herein we report a new type of stimuli-responsive luminescent liquid crystal that exhibits three luminescent colors, which can be switched by mechanical and thermal stimuli (Figure 1). The liquid crystal is composed of equimolar amounts of the dumbbell-shaped compound 1 and compound 2 (Scheme 1). The three luminescent colors observed are reddish-orange, yellow, and green, which are easily distinguished by the naked eye. Moreover, the LC mixture of 1 and 2 contains only one type of luminophore, 9,10-bis(phenylethynyl)anthracene, [34,35] and no additives are required to induce the luminescent color changes. Unlike crystalline materials, the thin-film states are easily prepared (see below). The change in the luminescent colors and the phase-transition behavior of the LC mixture are summarized in Figure 1.The mixture forms a thermotropic micellar cubic phase upon heating from room temperature to 146 8C. Recently thermotropic cubic phases classified as micellar cubic phases were reported. [25,36] The characterization of the LC phases is discussed in the Supporting Information. Under UV irradiation (365 nm), reddish-orange photoluminescence is observed for the micellar cubic phase (Figure 1, top left). We have found that me...

show abstract

“…[1][2][3][4][5] To induce change in the luminescent colors of organic and organometallic materials, one could switch the molecularly assembled structures. [4][5][6][7] Crystals, [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] liquid crystals, [25][26][27][28] and polymers [29][30][31][32] have been reported to change their luminescent colors by mechanical and thermal stimuli. The observed phenomena are referred to as piezo(mechano)chromic or thermochromic luminescence.…”

mentioning

confidence: 99%

Brightly Tricolored Mechanochromic Luminescence from a Single‐Luminophore Liquid Crystal: Reversible Writing and Erasing of Images

Sagara

¹

,

Kato

²

2011

View full text Add to dashboard Cite

Luminescent materials that switch their photoluminescent properties in response to various external stimuli have attracted much attention for a decade because of their potential application for memory devices, sensors, security materials, and informational displays. [1][2][3][4][5] To induce change in the luminescent colors of organic and organometallic materials, one could switch the molecularly assembled structures. [4][5][6][7] Crystals, [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] liquid crystals, [25][26][27][28] and polymers [29][30][31][32] have been reported to change their luminescent colors by mechanical and thermal stimuli. The observed phenomena are referred to as piezo(mechano)chromic or thermochromic luminescence. Such materials contain just one type of luminophore and they form only two luminescent states. In the condensed states, to date, multiemission colors that are generated from a single luminophore and switch between their colors using external stimuli have not been achieved for organic and organometallic materials; the one exception is a crystalline compound. [16] If such materials are prepared using liquid crystals, it leads to new applications of stimuli-responsive luminescent materials that are flexible, sophisticated, and highly functional.Liquid crystals are functional soft materials that exhibit mobile and ordered states. [33] Because of their dynamic properties, liquid crystals are good candidates for stimuliresponsive luminescent materials. [25][26][27][28] In our previous studies, we have prepared pyrene-, anthracene-, and naphthalenebased liquid crystals that show piezo(mechano)chromic luminescence and thermochromic luminescence in liquidcrystalline (LC) states. [25,26] However, multiluminescent colors have not been achieved for these LC materials.

show abstract

Hingeless Negative Linear Compression in the Mechanochromic Gold Complex [(C₆F₅Au)₂(μ‐1,4‐diisocyanobenzene)]

Woodall

¹

,

Beavers

²

,

Christensen

³

et al. 2013

View full text Add to dashboard Cite

show abstract

Dynamische Kristalle: visuell wahrnehmbare mechanochemische Lumineszenzänderungen von Gold‐ und anderen Übergangsmetallkomplexen

Cited by 39 publications

References 25 publications

Brightly Tricolored Mechanochromic Luminescence from a Single‐Luminophore Liquid Crystal: Reversible Writing and Erasing of Images

Brightly Tricolored Mechanochromic Luminescence from a Single‐Luminophore Liquid Crystal: Reversible Writing and Erasing of Images

Brightly Tricolored Mechanochromic Luminescence from a Single‐Luminophore Liquid Crystal: Reversible Writing and Erasing of Images

Hingeless Negative Linear Compression in the Mechanochromic Gold Complex [(C₆F₅Au)₂(μ‐1,4‐diisocyanobenzene)]

Contact Info

Product

Resources

About

Dynamische Kristalle: visuell wahrnehmbare mechanochemische Lumineszenzänderungen von Gold‐ und anderen Übergangsmetallkomplexen

Cited by 39 publications

References 25 publications

Brightly Tricolored Mechanochromic Luminescence from a Single‐Luminophore Liquid Crystal: Reversible Writing and Erasing of Images

Brightly Tricolored Mechanochromic Luminescence from a Single‐Luminophore Liquid Crystal: Reversible Writing and Erasing of Images

Brightly Tricolored Mechanochromic Luminescence from a Single‐Luminophore Liquid Crystal: Reversible Writing and Erasing of Images

Hingeless Negative Linear Compression in the Mechanochromic Gold Complex [(C6F5Au)2(μ‐1,4‐diisocyanobenzene)]

Contact Info

Product

Resources

About

Hingeless Negative Linear Compression in the Mechanochromic Gold Complex [(C₆F₅Au)₂(μ‐1,4‐diisocyanobenzene)]