title: Impact of constitutional isomerism on phosphorescence and anion-sensing properties of donor-acceptor organoboron Pt(II) complexes.
abstract: A new dimesitylboryl-functionalized molecule (NBppy) and its corresponding N^C chelate platinum(II) complex (Pt-NBppy) have been synthesized and fully characterized. The photophysical and electronic properties of NBppy and Pt-NBppy were examined and compared to their constitutional isomers, BNppy and Pt-BNppy, respectively. Due to the presence of the electron-donating diphenylamino group, the NBppy and BNppy compounds exhibit intense donor–acceptor charge transfer (CT) and bright blue fluorescence. Pt-NBppy displays weak phosphorescence, originating from a mixture of MLCT/π→π* and CT transitions while Pt-BNppy displays bright phosphorescence originating from a CT transition. The Lewis acidity of the isomers was examined by fluoride titration experiments, which established that BNppy exhibits much higher affinity towards fluoride ions than NBppy. In addition, while the phosphorescence of Pt-BNppy is quenched by fluoride addition, Pt-NBppy demonstrates an unusual turn-on phosphorescent response towards fluoride ions, which illustrate the distinct impact of constitutional isomers on phosphorescence and anion sensing.
authors.affiliation: Department of Chemistry, Queen's University, Kingston, Ontario, Canada K7L 3N6. suning.wang@chem.queensuca.ca.
authors.forename: Mei-Ni
authors.initials: MN
authors.lastname: Belzile
authors.forename: Xiang
authors.initials: X
authors.lastname: Wang
authors.forename: Zachary M
authors.initials: ZM
authors.lastname: Hudson
authors.forename: Suning
authors.initials: S
authors.lastname: Wang