Sagara Group

Published Papers

2023

55.“TBA”
R. Mori, C. Weder, Y. Sagara*
Manuscript submitted.
　　　　
54.“Mechanochromic luminescence of phase-separated hydrogels that contain cyclophane mechanophores”
S. Shimizu, H. Yoshida, K. Mayumi, H. Ajiro, Y. Sagara*
Mater. Chem. Front., 2023, 7, 4073–4079.

　　　　
53.“Microscopic strain mapping in polymers equipped with non-covalent mechanochromic motifs”
H. Traeger, D. J. Kiebala, C. Calvino, Y. Sagara, S. Schrettl, C. Weder, J. Clough*
Mater. Horiz. 2023, 10, 3467–3475.
52.“Tuning the mechanoresponsive luminescence of rotaxane mechanophores by varying the stopper size”
K. Hiratsuka, T. Muramatsu, T. Seki, C. Weder, G. Watanabe,* Y. Sagara*
J. Mater. Chem. C 2023, 11, 3949–3955. (Hot Paper, Front Cover)
51.“Force-induced Shuttling of Rotaxanes Controls Fluorescence Resonance Energy Transfer in Polymer Hydrogels”
T. Muramatsu, S. Shimizu, J. M. Clough, C. Weder,* Y. Sagara*
ACS Appl. Mater. Interfaces 2023, 15, 8502–8509. (Open Access)

2022

50.“Excited State Charge-Transfer Complexes Enable Fluorescence Color Changes in a Supramolecular Cyclophane Mechanophore”
S. Thazhathethil, T. Muramatsu, N. Tamaoki, C. Weder,* Y. Sagara*
Angew. Chem. Int. Ed. 2022, 61, e202209225. (Open Access)(Hot Paper, Back Cover)
49.“Crystal Structure of a 4,7-Bis(phenylethynyl)-2,1,3-benzothiadiazole-based Cyclophane and the Mechanoresponsive Luminescence”
K. Hiratsuka, T. S. Fazil, K. Takahashi,* T. Nakamura, Y. Sagara*
Bull. Chem. Soc. Jpn. 2022, 95, 1474–1480. (Selected Paper, Inside Cover)
48.“Supramolecular Rings as Building Blocks for Stimuli-Responsive Materials”
H. Traeger, A. Ghielmetti, Y. Sagara, S. Schrettl,* C. Weder*
Gels 2022, 8, 350.
47.“Strain-correlated mechanochromism in different polyurethanes featuring a supramolecular mechanophore”
H. Traeger, Y. Sagara, J. A. Berrocal, S. Schrettl,* C. Weder*
Polym. Chem. 2022, 13, 2860–2869.

2021

46.“Crystal structure of a 1,6-bis(phenylethynyl)pyrene-based cyclophane that exhibits mechanochromic luminescence”
S. Shimizu, S. Thazhathethil, K. Takahashi,* T. Nakamura, Y. Sagara*
Mol. Syst. Des. Eng. 2021, 6, 1039–1046. (Invited)
45.“Rotaxane-Based Dual Function Mechanophores Exhibiting Reversible and Irreversible Responses”
T. Muramatsu, Y. Okado, H. Traeger, S. Schrettl, N. Tamaoki, C. Weder,* Y. Sagara*
J. Am. Chem. Soc. 2021, 143, 9884–9892.
44.“Folded Perylene Diimide Loops as Mechanoresponsive Motifs”
H. Traeger, Y. Sagara, D. J. Kiebala, S. Schrettl, C. Weder*
Angew. Chem. Int. Ed. 2021, 60, 16191–16199.
43.“Mechanically Responsive Luminescent Polymers Based on Supramolecular Cyclophane
Mechanophores”
Y. Sagara,* H. Traeger, J. Li, Y. Okado, S. Schrettl, N. Tamaoki, C. Weder*
J. Am. Chem. Soc. 2021, 143, 5519–5525.
42.“Two-step mechanoresponsive luminescence and mechanical stimuli-induced release of small molecules exhibited by a luminescent cyclophane”
Y. Sagara,* K. Takahashi, A. Seki, T. Muramatsu, T. Nakamura, N. Tamaoki
J. Mater. Chem. C 2021, 9, 1671–1677.

2020

41.“Mechanical and Thermal Stimuli-induced Release of Toluene Included in Luminescent Crystals as One-dimensional Solvent Channels”
Y. Sagara,* K. Takahashi, T. Nakamura, N. Tamaoki
J. Mater. Chem. C 2020, 8, 10039–10046.
40.“Mechanochromic Luminescence from Crystals Consisting of Molecular Sheets Constructed by Intermolecular Hydrogen Bonds”
Y. Sagara,* K. Takahashi, T. Nakamura, N.Tamaoki
Chem. Asian J. 2020, 15, 478–482. (Invited)
(Special Issue: “100th Annual Meeting of the Chemical Society of Japan”)
39.“Crystal structure and thermoresponsive luminescence of a 9,10-bis(phenylethynyl)anthracene-based cyclophane”
Y. Sagara,* K. Takahashi, T. Nakamura, N. Tamaoki
Mol. Syst. Des. Eng. 2020, 5, 205–211. (Invited)
(Special Issue: “MSDE Emerging Investigators 2020”)

2019

38.“Mechanoresponsive Behavior of a Polymer-Embedded Red-Light Emitting Rotaxane Mechanophore”
T. Muramatsu, Y. Sagara,* H. Traeger, N. Tamaoki, C. Weder*
ACS Appl. Mater. Interfaces 2019, 11, 24571–24576.
37.“Rotaxane-based Mechanophores Enable Polymers with Mechanically Switchable White
Photoluminescence”
Y. Sagara,* M. Karman, A. Seki, M. Pannipara, N. Tamaoki, C. Weder*
ACS Cent. Sci. 2019, 5, 874–881.
36.“Photoinduced Emission Color Change of a Rubbed Film of a Bis(cyanostyryl)benzene Analogue”
R. Kaneko, Y. Sagara, S. Katao, N. Tamaoki, C. Weder, and H. Nakano*
Chem. Eur. J. 2019, 25, 6162–6169.
35.“Temperature Controlled Locally Excited and Twisted Intramolecular Charge Transfer State Dependent Fluorescence Switching in Triphenylamine-Thiazole Derivatives”
A. Kundu, S. Karthikeyan, Y. Sagara, D. Moon,* S. P. Anthony*
ACS Omega 2019, 4, 5147–5154.
34.“Functional Polymers Through Mechanochemistry”
S. Schrettla,* D. W. R. Balkenende, C. Calvino, M. Karman, A. Lavrenova, L. Neumann, Y. Sagara, E. Verde-Sesto, M. D. Giannantonio, K. M. Fromm, M. Lattuada, C. Weder*
Chimia 2019, 73, 7–11.
33.“A 1,6-Diphenylpyrene-based, Photoluminescent Cyclophane Showing a Nematic Liquid-crystalline Phase at Room Temperature”
Y. Sagara,* T. Muramatsu, N. Tamaoki
Crystals 2019, 9, 92. (Invited)
(Special Issue: Synthesis and Properties of Light-emitting Liquid Crystals)
32.“Mechanoresponsive Luminescent Polymer Blends Based on an Excimer-Forming Telechelic Macromolecule”
C. Calvino, Y. Sagara, V. Buclin, A. P. Haehnel, A. del Prado, C. Aeby, Y. C. Simon, S. Schrettl, C. Weder*
Macromol. Rapid Commun. 2019, 40, 1800705.

2018

31.“Cyclophane-Based Fluorescence Tuning Induced by Hydrostatic Pressure Changes”
Y. Sagara,* N. Tamaoki, G. Fukuhara*
ChemPhotoChem 2018, 2, 959–963.
30.“Unusual Fluorescent Photoswitching of Imidazole Derivatives: Role of Molecular Conformation and Twist Angle Controlled Organic Solid State Fluorescence”
A. Kundu, S. Karthiheyan, Y. Sagara, D. Moon, S. P. Anthony*
Phys. Chem. Chem. Phys. 2018, 20, 27385–27393.
29.“Linearly Polarized Photoluminescence from an Asymmetric Cyclophane Showing Thermo- and Mechanoresponsive Luminescence”
Y. Sagara,* A. Seki, Y. Kim, N. Tamaoki*
J. Mater. Chem. C 2018, 6, 8453–8459.
28.“Drastic Modulation of Stimuli-Responsive Fluorescence by a Subtle Structural Change of Organic Fluorophore and Polymorphism Controlled Mechanofluorochromism”
P. S. Hariharan, G. Parthasarathy, A. Kundu, S. Karthikeyan, Y. Sagara, D. Moon,* S. P. Anthony*
Cryst. Growth Des. 2018, 18, 3971–3979.
27.“Stimuli-Responsive Dual-Color Photon Upconversion: A Singlet-to-Triplet Absorption Sensitizer in a Soft Luminescent Cyclophane”
K. Mase, Y. Sasaki, Y. Sagara,* N. Tamaoki, C. Weder, N. Yanai,* N. Kimizuka*
Angew. Chem. Int. Ed. 2018, 57, 2806–2810.
26.“Rotaxanes as Mechanochromic Fluorescent Force Transducers in Polymers”
Y. Sagara,* M. Karman, E. Verde-Sesto, K. Matsuo, Y. Kim, N. Tamaoki, C. Weder*
J. Am. Chem. Soc. 2018, 140, 1584–1587.

2017

25.“Mechanoresponsive Luminescence and Liquid-crystalline Behaviour of a Cyclophane Featuring Two 1,6-Bis(phenylethynyl)pyrene Groups”
Y. Sagara,* N. Tamaoki*
RSC Adv. 2017, 7, 47056–47062.
24.“Asymmetric Cyclophanes Permit Access to Supercooled Nematic Liquid Crystals with Stimuli-responsive Luminescence”
Y. Sagara,* C. Weder, N. Tamaoki*
Chem. Mater. 2017, 29, 6145–6152.
23.“Mechano- and Thermoresponsive Photoluminescent Supramolecular Polymer”
A. Lavrenova, D. W. R. Balkenende, Y. Sagara, S. Schrettl, Y. C. Simon, C. Weder*
J. Am. Chem. Soc. 2017, 139, 4302–4305.
22.“Temperature-Dependent Mechanochromic Behavior of Mechanoresponsive Luminescent Compounds”,
Y. Sagara,* K. Kubo, T. Nakamura, N. Tamaoki, C. Weder*
Chem. Mater. 2017, 29, 1273–1278.

2016

21.“Tuning the Thermo- and Mechanoresponsive Behavior of Luminescent Cyclophanes”
Y. Sagara,* C. Weder, N. Tamaoki*
RSC Adv. 2016, 6, 80408–80414.
20.“A Mechano- and Thermoresponsive Luminescent Cyclophane”
Y. Sagara,* Y. C. Simon, N. Tamaoki, C. Weder*
Chem. Commun. 2016, 52, 5694–5697.
19.“A Thermo- and Mechanoresponsive Cyano-substituted Oligo(p-Phenylene Vinylene) Derivative with Five Emissive States”
Y. Sagara,* A. Lavrenova, A. Crochet, Y. C. Simon, K. M. Fromm, C. Weder*
Chem. Eur. J. 2016, 22, 4374–4378.
18.“Mechanoresponsive Luminescent Molecular Assemblies: An Emerging Class of Materials”
Y. Sagara,* S. Yamane, M. Mitani, C. Weder, T. Kato*
Adv. Mater. 2016, 28, 1073–1095. (Front Cover Picture)

2005-2015

17.“Mechanochemistry in Polymers with Supramolecular Mechanophores”
A. P. Haehnel, Y. Sagara, Y. C. Simon,* C. Weder*
Top. Curr. Chem. 2015, 369, 345−375.
16.“Thermal or Mechanical Stimuli-Induced Photoluminescence Color Change of a Molecular Assembly Composed of an Amphiphilic Anthracene Derivative in Water”
Y. Sagara, T. Komatsu, T. Terai, T. Ueno, K. Hanaoka, T. Kato, T. Nagano*
Chem. Eur. J. 2014, 20, 10397−10403.
15.“Covalent Attachment of Mechanoresponsive Luminescent Micelles to Glasses and Polymers in Aqueous Conditions”
Y. Sagara, T. Komatsu, T. Ueno, K. Hanaoka, T. Kato, T. Nagano*
J. Am. Chem. Soc. 2014, 136, 4273−4280.
14.“A Water-soluble Mechanochromic Luminescent Pyrene Derivative Exhibiting Recovery of the Initial Photoluminescence Color in a High-humidity Environment”
Y. Sagara, T. Komatsu, T. Ueno, K. Hanaoka, T. Kato, T. Nagano*
Adv. Funct. Mater. 2013, 23, 5277–5284.
13.“Steric Effects on Excimer Formation for Photoluminescent Smectic Liquid-crystalline Materials”
S. Yamane, Y. Sagara, T. Kato*
Chem. Commun. 2013, 49, 3839–3841.
12.“Mechanochromic Luminescent Liquid Crystals Based on a Bianthryl Moiety”
Shogo Yamane, Yoshimitsu Sagara, Toshiki Mutai, Koji Araki, Takashi Kato*
J. Mater. Chem. C 2013, 1, 2648–2656.
11.“Stimuli-Responsive Photoluminescent Liquid Crystals”
S. Yamane, K. Tanabe, Y. Sagara, T. Kato*
Top. Curr. Chem. 2012, 318, 395–406.
10.“Brightly Tri-colored Mechanochromic Luminescence from the Single Luminophore of a Liquid Crystal: Reversible Writing and Erasing of the Images”
Y. Sagara, T. Kato*
Angew. Chem. Int. Ed. 2011, 50, 9128–9132. (Inside Cover Picture)
9.“Piezochromic Luminescence of Amide and Ester Derivatives of Tetraphenylpyrene—Role of Amide Hydrogen Bonds in Sensitive Piezochromic Response”
M. Sase, S. Yamaguchi, Y. Sagara, I. Yoshikawa, T. Mutai, K. Araki*
J. Mater. Chem. 2011, 21, 8347–8354.
8.“A Mechanical and Thermal Responsive Luminescent Liquid Crystal Forming a Colourless Film under Room Light”
Y. Sagara, T. Kato*
Supramol. Chem. 2011, 23, 310–314.
7.“A Thermoresponsive Photoluminescent Smectic Liquid Crystal: Change of Photoluminescent Color on the Smectic–Smectic Phase Transition”
S. Yamane, Y. Sagara, T. Kato*
Chem. Commun. 2009, 3597–3599.
6.“Mechanically Induced Luminescence Changes in Molecular Assemblies”
Y. Sagara, T. Kato,*
Nat. Chem. 2009, 1, 605–610.
5.“A Stimuli-Responsive, Photoluminescent, Anthracene-Based Liquid Crystal: Emission Color Determined by Thermal and Mechanical Processes”
Y. Sagara, S. Yamane, T. Mutai, K. Araki, T. Kato*
Adv. Funct. Mater. 2009, 19, 1869–1875.
4.“Stimuli-Responsive Luminescent Liquid Crystals: Change of Photoluminescent Colors Triggered by a Shear-Induced Phase Transition”
Y. Sagara, T. Kato*
Angew. Chem. Int. Ed. 2008, 47, 5175–5178.
3.“Material Design for Piezochromic Luminescence: Hydrogen-Bond-Directed Assemblies of a Pyrene Derivative”
Y. Sagara, T. Mutai, I. Yoshikawa, K. Araki*
J. Am. Chem. Soc. 2007, 129, 1520–1521.
2.“Uniaxially Parallel Alignment of a Smectic A Liquid-Crystalline Rod−Coil Molecule and Its Lithium Salt Complexes Using Rubbed Polyimides”
Y. Iinuma, K. Kishimoto, Y. Sagara, M. Yoshio, T. Mukai, I. Kobayashi, H. Ohno, T. Kato*
Macromolecules 2007, 40, 4874–4878.
1.“Two Dimensionally Ion-Conductive Liquid Crystals of Cholesterol/Tetra(Ethylene Oxide) Block Molecules”
K. Kishimoto, Y. Sagara, T. Mukai, H. Ohno, N. Tamaoki, T. Kato*
Mol. Cryst. Liq. Cryst. 2005, 435, 777–785.

Awards

July 2020
Prof. Sagara received the Suematsu Challenging Research Award.
April 2019
Prof. Sagara received The Young Scientists’ Prize from MEXT.