CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, Key Laboratory of Optoelectronic Science and Technology in Anhui Province, University of Science and Technology of China, Hefei, Anhui, PR China.
J Colloid Interface Sci. 2013 Jun 15;400:116-22. doi: 10.1016/j.jcis.2013.02.049. Epub 2013 Mar 14.
Herein, a novel single-chain coumarin-substituted diacetylene monomer (CODA) was synthesized. CODA LB films exhibited obvious chirality although CODA monomer was achiral. Upon UV irradiation, CODA LB films could be polymerized into blue form and exhibit reversible thermochromism and chiroptical properties. Strong intermolecular interaction among the coumarin chromophores was assumed to be responsible for the complete reversibility of absorption and chiroptical changes for PCODA films upon thermal stimulus. And the helical packing of the coumarin chromophores seemed to play a dominating role in the subsequent formation of the helical PDA backbone. Moreover, the single-chain CODA monomer could be further photo-dimerized, and a novel gemini-type diacetylene monomer (DCODA) could be prepared. The effects of the photo-dimerization reaction of the coumarin moieties on the thermochromism and chiroptical properties of the resulting PDCODA films had been evaluated. The dimerization of head groups would enhance the thermal stability of PDCODA films but inhibit the chirality formation for PDA backbone.
本文合成了一种新型的单链香豆素取代二炔单体（CODA）。尽管 CODA 单体无手性，但 CODA LB 膜表现出明显的手性。紫外光照射下，CODA LB 膜可聚合形成蓝色形态，并表现出热致变色和手性光学性能的可逆性。假定香豆素发色团之间的强分子间相互作用是 PCODA 薄膜在热刺激下吸收和手性变化完全可逆的原因。香豆素发色团的螺旋堆积似乎在手性 PDA 主链的后续形成中起主导作用。此外，单链 CODA 单体可进一步光二聚化，从而制备新型的双子型二炔单体（DCODA）。评估了香豆素部分的光二聚反应对所得 PDCODA 薄膜的热致变色和手性光学性质的影响。头基的二聚化会增强 PDCODA 薄膜的热稳定性，但抑制 PDA 主链的手性形成。
