title: On the development of sensor molecules that display Fe(III)-amplified fluorescence.
abstract: Incorporation of a tailor-made size-restricted dithia-aza-oxa macrocycle, 1-oxa-4,10-dithia-7-aza-cyclododecane, via a phenyl linker into two fluorescent sensor molecules with electronically decoupled, rigidly fixed, and sterically preoriented architectures, a 1,3,5-triaryl-Delta2-pyrazoline and a meso-substituted boron-dipyrromethene (BDP), yields amplified fluorescence in the red-visible spectral range upon binding of Fe(III) ions. The response to Fe(III) and potentially interfering metal ions is studied in highly polar aprotic and protic solvents for both probes as well as in neat and buffered aqueous solution for one of the sensor molecules, the BDP derivative. In organic solvents, the fluorescence of both indicators is quenched by an intramolecular charge or electron transfer in the excited state and coordination of Fe(III) leads to a revival of their fluorescence without pronounced spectral shifts. Most remarkably, the unbound BDP derivative shows dual emission in water and can be employed for the selective ratiometric signaling of Fe(III) in buffered aqueous solutions.
authors.affiliation: Institute of Organic Chemistry, National Academy of Sciences of the Ukraine, 02094 Kiev, Ukraine. timophei@bricks.kiev.ua
authors.forename: Julia L
authors.initials: JL
authors.lastname: Bricks
authors.forename: Anton
authors.initials: A
authors.lastname: Kovalchuk
authors.forename: Christian
authors.initials: C
authors.lastname: Trieflinger
authors.forename: Marianne
authors.initials: M
authors.lastname: Nofz
authors.forename: Michael
authors.initials: M
authors.lastname: Büschel
authors.forename: Alexei I
authors.initials: AI
authors.lastname: Tolmachev
authors.forename: Jörg
authors.initials: J
authors.lastname: Daub
authors.forename: Knut
authors.initials: K
authors.lastname: Rurack