A Study of Host-guest relationship between Cucurbit [n] uril and N-2-aryl-1, 2, 3 triazole.

摘要

The Cucurbit [n] uril molecules are macromolecular constructs within the supramolecular family. They are composed of 'n' number of glycouril units which are linked by methylene groups. Cucurbiturils CB[n]'s [n=5, 6, 7, 8, 9, 10], also well known as pumpkin shaped macrocycles have been generating tremendous interest in the supramolecular community because of their exceptional properties in self organization , their use in drug delivery, fluorescence enhancement, water purification and as molecular level machines etc. The CB [n]'s act as host molecules to trap various organic molecules like hetero [4] pseudorotaxanes, azobenzenes, within their cavity and form non-covalent host guest relationship. Among all the members of CB [n] family the CB [7] host molecule shows strongest interaction towards both positively charged and neutral guest molecules along with fair water solubility. One important group of triazole, is the N-2-aryl-1, 2, 3 – triazole, where two aromatic rings have coplanar conformation and with characteristic electron density and unique photonic properties. I have synthesized 4-(4-phenyl-2H -1, 2, 3-triazol-2-yl) pyridine1, in order to examine how this triazole moiety bind, in the cavity of CB [7] molecule. So in my research thesis, I did 1H NMR titrations of CB [7] complexes of with 4-(4-phenyl-2H-1, 2, 3-triazol-2-yl) pyridine to study how addition of CB [7] affected the chemical shift of protons of NAT's and also how it affected fluorescence of 4-(4-phenyl-2 H-1, 2, 3-triazol-2-yl) pyridine after binding with CB [7].;Another project I was working on as co-author was named 'Ambient Schmittel Cyclization promoted by chemoselective triazole-gold catalyst' in which I have synthesized different substrates which involved a Sonogashira coupling reaction.