The research front on molecular functional switches

Abstract

The 4 International Workshop on Organic Photoswitchable Multifunctional Molecules and Materials was held between 25 and 27 October 2009 in East China University of Science & Technology (ECUST), Shanghai. It was a great event for academic circles, and at the same time provided an excellent chance for communication between international scholars from the field of organic photoswitchable functional materials. Along with a successful series of workshops on this topic, such as those held by Japan-France (Shonan, 2006), France-Russia (Saissac, 2007) and France-Japan (Arras, 2008), ECUST (China) and CNRS's GDRI (France) joined together to host this continued workshop on novel photoswitchable multifunctional molecules and materials. This workshop covered all aspects from molecular design to devices using photo-switchable materials, and was intended as a forum for further interdisciplinary discussion and international cooperation. The workshop was presided over by Prof. Yu Pei and Prof. He Tian. During the workshop, more than 50 experts and 50 Ph.D. candidates from Canada, Germany, Italy, Hong Kong, France, Japan, South Korea, Sweden, Singapore, the USA and China presented and discussed the latest research findings, interpretations and ideas relating to organic photoswitchable multifunctional materials. Many famous professors came to the gathering, with the aim of better promoting the development of advanced materials and also mutual understanding. Following the workshop, we have received 17 high quality papers from the scholars for a special issue of Frontiers of Chemistry in China. This issue provides a unique opportunity for scientists in this area to exchange ideas and share in the achievements in the field of organic functional materials, mainly focussing on organic chemosensors and photochromic molecules. As we know, the most convenient way to introduce a photoswitching function into a molecular system is to use photochromic units as photo-functional units. A particularly interesting photochromic unit is diarylethene, which reversibly changes its π-conjugation and structure upon irradiation. In this workshop, many lectures were given on photochromic diarylethenes. Therefore, taking into consideration the requirements of most international participants, we decided to launch another special issue on the topic of photochromic molecules, namelyDyes and Pigments (Guest Editors: Prof. Neil Branda and Prof. He Tian), which will include papers mostly from foreign scientists. Of course, this issue in Frontiers of Chemistry in China should reflect some of the progress in the photochromic field in China. Two research articles by Prof. Yi Chen et al. and Prof. Shou-Zhi Pu et al. report new photochromic diarylethene compounds for holographic optical recording and two-photon absorption, respectively. Owing to their direct toxic effects on human beings, animals and plants, chemical warfare agents (CWAs) and their mimics have become widespread in agriculture and chemical warfare. A short review by Prof. Chun-Hua Yan and his coworkers contains recent reports on the design of fluorescent molecular switches and their advantages in the detection of CWAs. It is believed that extensive interest in this field has accelerated the development of novel fluorescent molecular switches and detection techniques. Seven research articles (from the groups of Yun-Bao Jiang, Xiao-Jun Peng, JianZhang Zhao, Wei-Hong Zhu, Jian-Li Hua, Juan Xie and Yong-Shu Xie) show how to construct new organic fluorescent sensing molecules with highly selectivity and sensitivity and even with a new signal-transduction mechanism. It is interesting to note that a new switching molecule based on ferrocene can be controlled and detected by an aggregation-induced emission (AIE) phenomenon (research article by Dr. Dong Zhang). For organic compounds, switching at the molecular level is important in materials for sensing, separation, and drug delivery. In response to changes in temperature, concentration, media, light, time, and the presence or absence of other ions or molecules, organic compounds can aggregate or deaggregate, which triggers various chemical, physical, and biological phenomena. Prof. Shu Wang and his coworkers prepared a water-soluble conjugated polyfluorene with He TIAN Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science & Technology, Shanghai 200237, China E-mail: tianhe@ecust.edu.cn Front. Chem. China 2010, 5(2): 113–114 DOI 10.1007/s11458-010-0100-1