Cyclometalated N-Difluoromethylbenzimidazolylidene Platinum(II) Complexes with Built-in Secondary Coordination Spheres: Photophysical Properties and Bioimaging

Jingli Zhang; Zengyu Zhang; Mengrui Su; Xingyu Xu; Rongyao Gao; Bingran Yu; Xiaoyu Yan

doi:10.1021/acs.inorgchem.4c03713

Cyclometalated N-Difluoromethylbenzimidazolylidene Platinum(II) Complexes with Built-in Secondary Coordination Spheres: Photophysical Properties and Bioimaging

Inorg Chem. 2024 Nov 15. doi: 10.1021/acs.inorgchem.4c03713. Online ahead of print.

Authors

Jingli Zhang¹, Zengyu Zhang¹, Mengrui Su², Xingyu Xu³, Rongyao Gao¹, Bingran Yu², Xiaoyu Yan¹

Affiliations

¹ Key Laboratory of Advanced Light Conversion Materials and Biophotonics, School of Chemistry and Life Resources, Renmin University of China, Beijing 100872, China.
² College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
³ Department of Chemistry, Xinzhou Teachers University, Xinzhou 034000, Shanxi, China.

PMID: 39546802
DOI: 10.1021/acs.inorgchem.4c03713

Abstract

Bidentate Pt(II) complexes with cyclometalated N-heteroarene or N-heterocyclic carbene (NHC) ligands have been extensively studied as phosphorescent emitters over the past two decades. Herein, we introduce a difluoromethyl group (CF₂H) into the wingtip of NHCs, where CF₂H acts as a lipophilic hydrogen bond (HB) donor. Their cyclometalated Pt(II) complexes show excellent PLQYs (up to 93%) and phosphorescence lifetimes mainly due to the rigid structure with hydrogen bonding between the CF₂H group and the adjacent O atom at the β-diketonate ligand. Bioimaging studies demonstrate high cellular uptake efficiency and deep tumor penetration capability of complex 7 in HeLa cells and multicellular tumor spheroids, highlighting their potential as bioimaging probes.