Defect-sensitive crystals based on diaminomaleonitrile-functionalized Schiff base with aggregation-enhanced emission

Tianyu Han,Bin Tong,Sijie Chen,Yuping Dong,Jacky W Y Lam,Herman H Y Sung,Engui Zhao,Ben Zhong Tang,Ni Xie,Yuning Hong,Na Zhao

doi:10.1039/c3tc31562b

Abstract

In this work, we report the synthesis and photophysical studies of a new luminogen, A3MN, a diaminomaleonitrile-functionalized Schiff base. A3MN is aggregation-enhanced emission (AEE)-active: the emission of A3MN is enhanced with the aggregate formation. A3MN also possesses twisted intramolecular charge transfer (TICT) properties, showing noticeable solvatofluorochromism. Interestingly, the crystals of A3MN are nonemissive; the defect areas of the crystal, however, are highly emissive, as confirmed by spectroscopic methods and confocal microscopy. By taking advantage of this defect sensitive feature, a “turn-on” type of mechanofluorochromic material is developed, the emission of which is significantly enhanced under pressure or shear force. The detection limit reaches 0.1 Newton owing to its “turn-on” nature. Such defect-induced emission also renders A3MN sensitive to various kinds of mechanical actions, including hitting, friction, sculpture, and ultrasonic vibration.

Highlights

Theta range for data collection Index ranges Reflections collected Independent reflections Completeness to theta = 66.50° Absorption correction Max. and min. transmission Refinement method
High resolution mass spectra (HRMS) were recorded on a GCT premier CAB048 mass spectrometer operated in MALDI-TOF mode
Powder X-ray diffraction (XRD) patterns were recorded on an X'pert PRO, PANalytical diffractometer

Summary

Introduction

Y. Sung,a Yuping Dong,b Bin Tong*b and Ben Zhong Tang*acd aDepartment of Chemistry, Institute for Advanced Study, State Key Laboratory of Molecular Neuroscience, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, China. E-mail: tangbenz@ust.hk; fax: +852 23581594 bCollege of Materials Science and Engineering, Beijing Institute of Technology, 5 South Zhongguancun Street, Beijing, 100081, China. E-mail: tongbin@bit.edu.cn; fax: +86-10-6894-8982 cGuangdong Innovative Research Team, SCUT-HKUST Joint Research 50 Laboratory, State Key Laboratory of Luminescent Materials and Device, South China University of Technology (SCUT), Guangzhou 510640, China dHKUST Shenzhen Research Institute, No 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China *E-mail: tangbenz@ust.hk; tongbin@bit.edu.cn

Results

Conclusion