Anion binding by biotin[6]uril in waterElectronic supplementary information (ESI) available: Binding studies, X-ray crystal structure and Job plots. CCDC 1029718. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4ob02211d

In this contribution we show that the newly discovered 6 + 6 biotin-formaldehyde macrocycle Biotin[6]uril binds a variety of anionic guest molecules in water. We discuss how and why the anions are bound based on data obtained using NMR spectroscopy, mass spectrometry, isothermal titration calorimetry (ITC), computational calculations and single crystal X-ray crystallography. We show that the newly discovered 6 + 6 biotin-formaldehyde macrocycle Biotin[6]uril binds a variety of anionic guest molecules in water. We discuss how and why the anions are bound based on data obtained using NMR spectroscopy, mass spectrometry, isothermal titrations calorimetry (ITC), computational calculations and single crystal X-ray crystallography.