Mechanochemical changes on cyclometalated Ir(iii) acyclic carbene complexes – design and tuning of luminescent mechanochromic transition metal complexes

Jingqi, H., Tang, K.-M., Cheng, S.-C., Ng, C.-O., Chun, Y.-K., Chan, S.-L., Yiu, S.-M., Tse, M.-K., Roy, V. A.L. and Ko, C.-C. (2020) Mechanochemical changes on cyclometalated Ir(iii) acyclic carbene complexes – design and tuning of luminescent mechanochromic transition metal complexes. Inorganic Chemistry Frontiers, 7, pp. 786-794. (doi: 10.1039/C9QI01278H)

Abstract

A new class of luminescent mechanochromic cyclometalated Ir(III) complexes with pyridyl acyclic carbene ligands have been developed. These complexes shown predominant MLCT phosphorescence mixed with 3LC character. In the solid state and neat film, the emission of these complexes show significant red-shift upon mechanical grinding. On the basis of XRD, X-ray crystallography, Raman spectroscopy and DFT calculation, the mechanically-induced variations of the molecular packing and the structural conformation have been elucidated. With the understanding of their mechanochemical changes, it enables the design of luminescent mechanochromic compounds with tailored mechanochromic properties, including the emission color and the mechanochromic shift, through judicious structural modifications of the ligands as illustrated in the complexes reported in this work. It would also open up new design of mechanoresponsive materials.

• Item Type: Articles
• Additional Information: This work has been supported by the General Research Fund (Project No. CityU 11306217 and CityU 11303318). J. Han acknowledges receipt of a University Postgraduate Studentship administrated by City University of Hong Kong.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Vellaisamy, Professor Roy
• Authors: Jingqi, H., Tang, K.-M., Cheng, S.-C., Ng, C.-O., Chun, Y.-K., Chan, S.-L., Yiu, S.-M., Tse, M.-K., Roy, V. A.L., and Ko, C.-C.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Inorganic Chemistry Frontiers
• Publisher: Royal Society of Chemistry
• ISSN: 2052-1553
• ISSN (Online): 2052-1553
• Published Online: 02 December 2019