New progress in organometallic micro and nano crystals of the Institute of chemistry, Chinese Academy of Sciences

Polymorphism and anisotropy are two basic properties of crystal materials Through the regulation of intermolecular interaction and assembly mode, polymorphic luminescent crystals can be obtained from a single molecule At the same time, anisotropy makes molecular crystals have different physical and chemical properties in different directions Organic micro nano crystalline materials have the characteristics of high regularity and few structural defects, which are considered as one of the best choices to reveal the intrinsic characteristics of materials and construct high-performance optoelectronic devices The preparation of polymorphic luminescent micro / nano crystals from a single molecule and the study of their structure dependent luminescent anisotropy not only provide the material basis for nanophotonics, but also provide an important basis for revealing the structural relationship of organic luminescent crystals In recent years, with the support of NSFC and the leading project of Chinese Academy of Sciences, the research team of optical functional materials and photoelectrochemistry in the Key Laboratory of Institute of chemistry, Chinese Academy of Sciences, has synthesized a series of stimulus response optical functional molecular materials and films using the molecular designability and strong assembly ability of organometallic compounds (j.am Chem SOC 2018, 140 , 12337-12340; J am Chem SOC 2018, 140, 7723-7729); and took the lead in the preparation of high regularity binary micro nano crystals of organometallic compounds, realizing three-wire state tunable luminescence based on efficient light trapping energy transfer (J am Chem SOC 2018, 140, 4269-4278; angel Chem Int ed 2018, 57, 7820-7825) Recently, the team has successfully prepared the yellow luminescent lamellar crystal ptd-y and green luminescent rod crystal ptd-g of organoplatinum complex PTD by solution reprecipitation The experimental results of angle dependent polarization luminescence show that the lamellar crystal exhibits strong anisotropy of phosphorescence, while the green luminescence of rod crystal is almost isotropic under the same test conditions According to the crystal structure and theoretical calculation, the anisotropy of crystal luminescence benefits from the parallel orientation of molecular transition dipole moment in crystal structure, while the isotropy of crystal luminescence is caused by the cross orientation of molecular transition dipole moment Furthermore, the isotropic red luminescent platinum complex (PTA) was doped into the lamellar crystal of PTD (the receptor component is less than 3%) by binary co assembly The polarized phosphorescence amplification of red luminescent of the receptor was realized by simulating the capture energy transfer in nature This work reveals the important structural relationship between the transition dipole moment and the luminescent anisotropy of molecular crystals, and shows the potential application value of photofunctional organometallic compounds in the micro nano luminescent crystals and nano photonics The work was published in J am Chem SOC (J am Chem SOC 2019, 141, 6157-6161), and was selected as the cover of 17th issue of Journal of American Chemical Society 2019 (frontcover, 01-may-2019) Sun Mengjia and Liu Yingying, Ph.D students of the Institute of chemistry, are the co first authors of the paper, and the corresponding authors are Zhong Yuwu, Zhao Yongsheng and Yao Jiannian.