Rigidly Tethered Bis-phosphoric Acids: Generation of Tunable Chiral Fluorescent Frameworks and Unexpected Selectivity for the Detection of Ferric Ions

5 years ago

Rigidly Tethered Bis-phosphoric Acids: Generation of Tunable Chiral Fluorescent Frameworks and Unexpected Selectivity for the Detection of Ferric Ions

Raja Mitra, Frescilia Octa-Smolin, Linda Stegemann, Cristian Strassert, Constantin G. Daniliuc, Maike Thiele, Jochen Niemeyer

We describe the straightforward synthesis of a series of bis-phosphoric acids (R,R)-1 a–d, featuring two chiral 1,1′-binaphthyl-phosphoric acid units that are tethered by rigid, π-conjugated linkers. The nature of the linker has a profound influence on the properties of the bis-phosphoric acids, such as their self-association behavior and their interaction with metal ions. This led to the identification of one preferred bis-phosphoric acid (R,R)-1 d, which shows selective fluorescence quenching in the presence of ferric ions (Fe3+). Thus, (R,R)-1 d could be applied for the detection of Fe3+, even in the presence of a variety of other metal ions. The chiral nature of the bis-phosphoric acid enables the interaction with Fe3+ to be followed by CD spectroscopy, providing a complementary detection mode with the same probe. Iron turns me off: The preparation and analysis of a series of rigidly tethered 1,1′-binaphthyl-phosphoric acids led to the identification of a novel probe for ferric ions (see figure). The presence of Fe3+ can be detected by means of CD or fluorescence spectroscopy with high chemoselectivity.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/chem.201700954