title: Demonstration of bidirectional photoinduced electron transfer (PET) sensing in 4-amino-1,8-naphthalimide based thiourea anion sensors.
abstract: The thiourea based 4-amino-1,8-naphthalimide molecules 1-5 were designed as fluorescent anion sensors and their photophysical properties investigated upon recognition of biologically relevant anions such as acetate, dihydrogen phosphate and fluoride in DMSO. Synthesised in a single step from their respective aniline precursors, 6-9, these molecules were designed on the fluorophore-spacer-receptor principle, where in the case of sensors 1-3 the thiourea anion recognition moieties were connected to the fluorophore via the 4-amino moiety, while sensors 4 and 5 had the thiourea moieties connected to the 'imide' via a CH2 spacer. The current study showed that 1-5 operated as photoinduced electron transfer (PET) sensors, as no significant changes were observed in their absorption spectra, while their fluorescence emissions were quenched upon recognition of ions such as AcO(-), H2PO4(-) and F(-), which demonstrates that bidirectional PET sensing occurs in such naphthalimide based anion sensors.
authors.affiliation: School of Chemistry, Centre of Synthesis and Chemical Biology, University of Dublin, Trinity College Dublin, Dublin2, Ireland.
authors.forename: Emma B
authors.initials: EB
authors.lastname: Veale
authors.forename: Gillian M
authors.initials: GM
authors.lastname: Tocci
authors.forename: Frederick M
authors.initials: FM
authors.lastname: Pfeffer
authors.forename: Paul E
authors.initials: PE
authors.lastname: Kruger
authors.forename: Thorfinnur
authors.initials: T
authors.lastname: Gunnlaugsson
mesh_terms: D015057:1-Naphthylamine / Q000031:analogs & derivatives* / Q000737:chemistry; D000085:Acetates / Q000032:analysis; D000838:Anions; D004121:Dimethyl Sulfoxide; D004579:Electron Transport; D005453:Fluorescence; D005459:Fluorides / Q000032:analysis; D053644:Naphthalimides / Q000737:chemistry*; D010710:Phosphates / Q000032:analysis; D055668:Photochemical Processes; D010777:Photochemistry / Q000295:instrumentation / Q000379:methods*; D015363:Quinolones / Q000737:chemistry*; D013890:Thiourea / Q000737:chemistry*
chemical_list: D000085:Acetates; D000838:Anions; D053644:Naphthalimides; D010710:Phosphates; D015363:Quinolones; C086538:4-amino-1,8-naphthalimide; D015057:1-Naphthylamine; D013890:Thiourea; D005459:Fluorides; D004121:Dimethyl Sulfoxide