| 초록 |
Carbon–carbon bonds are one of the most important covalent bonds in organic and polymeric materials. Although the bond dissociation energy of carbon–carbon bond in ethane is relatively high, those of the central carbon–carbon bonds in tetraarylethane derivatives are much lower and, therefore, such covalent bonds can act as dynamic covalent bonds in some cases. In this study, we focused on the design of mechanochromic polymers with tetraarylethane derivatives. Diarylbibenzofuranone (DABBF) was employed as the tetraarylethane derivative.1,2 The central carbon–carbon bonds in DABBF units afforded the corresponding arylbenzofuranone radicals with blue color by homolytic cleavage in response to mechanical stress, and the regeneration of the carbon–carbon bonds was confirmed.3-15 In addition, the mechano-responsiveness was investigated by electron paramagnetic resonance (EPR) spectroscopic measurements. The relationship between mechanochromic properties and polymer structures in DABBF-containing mechanochromic polymers was investigated. Furthermore, recent progress in the development of mechanochromic polymers with different mechanochromophores will be introduced. (1) H. Otsuka et al., Angew. Chem. Int. Ed., 51, 1138 (2012). (2) H. Otsuka et al., J. Am. Chem. Soc., 136, 11839 (2014). (3) H. Otsuka et al., Angew. Chem. Int. Ed., 54, 6168 (2015). (4) H. Otsuka et al., Chem. Commun., 52, 10482 (2016). (5) H. Otsuka et al., ACS Macro Lett., 4, 1307 (2016). (6) H. Otsuka et al., ACS Macro Lett., 5, 1124 (2016). (7) H. Otsuka et al., Macromolecules, 49, 5903 (2016). (8) H. Otsuka et al., Polym. Chem., 8, 2115 (2017). (9) H. Otsuka et al., Chem. Euro. J., 24, 3170 (2018). (10) H. Otsuka et al., ACS Macro Lett., 7, 556 (2018). (11) H. Otsuka et al., ACS Macro Lett., 7, 1087 (2018). (12) H. Otsuka et al., ACS Macro Lett., 7, 1359 (2018). (13) J. S. Moore, H. Otsuka et al., J. Am. Chem. Soc., 141, 1898 (2018). (14) H. Otsuka et al., Polym. Chem., 10, 2636 (2019). (15) H. Otsuka et al., Chem. Commun., 55, 6831 (2019). |
