Mohammad Alnajjar

• This doctoral thesis provides insights into the chemistry of host-guest complexes of hydrophobic amino molecules or hydrophobic amines attached with dyes, and their characteristics after complexation with cucurbit[n]urils (n = 7 and 8) was studied. It describes how to calculate the binding constants by different methods and techniques with minimum error and propagation error. Different types of complex can be formed, accompanied by changes in guest luminescence properties after complexation. The first project in the thesis presents a new fluorophore class for the design of reporter dyes for supramolecular host-guest complex formation with cucurbit[7]uril (CB7). The boron-dipyrromethene group (BODIPY) contains protonatable aniline nitrogen in the meso-position of the BODIPY chromophore, which was functionalized with known binding motifs for CB7. The second project in the thesis describes the formation of supramolecular complexation between cucurbit[n]urils (n = 7 and 8) and an amphiphilic pyridinium-functionalized anthracene (AnPy) in aqueous solution. The host-guest complexation between CBn and AnPy was studied in detail by using optical spectroscopy. The third project in the thesis describes how to use different techniques to calculate accurate and precise binding constants with CB7, and how to establish a series of reference compounds to determine CB7 binding affinities by direct and competitive titrations. The compounds have been selected according to their commercial availability to be suitable for various measurement techniques. The binding affinity of berberine chloride was established as a central reference point, which could be measured by fluorescence spectroscopy, ITC, and 1H NMR. The sensitivity of its Ka value to trace impurities in Millipore water was observed in direct titrations but not in competitive titrations. Within a series of competition experiments, reference compounds were established to cover a wide range of affinities (mM-fM).