title: Inclusion of carboxyl function inside of cucurbiturils and its use in molecular switches.
abstract: We have prepared organic guest molecules in which two pyridinium rings are connected through an aromatic/aliphatic bridge bearing a carboxyl group. The supramolecular interactions between these guests and macrocyclic hosts cucurbit[7]uril (CB7) and cucurbit[8]uril (CB8) has been studied. We have demonstrated that the binding modes of the complexes depend on the type of central bridge present in the guest molecules and the size of the macrocycle. We have also showed that the binding mode between cucurbiturils and guests with aromatic bridges is pH independent. On the other hand, a guest containing an aliphatic bridge and CB7 formed a pseudorotaxane, which behaved as a pH-driven molecular switch.
authors.affiliation: Department of Chemistry, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic.
authors.forename: Viktor
authors.initials: V
authors.lastname: Kolman
authors.forename: Petr
authors.initials: P
authors.lastname: Kulhanek
authors.forename: Vladimir
authors.initials: V
authors.lastname: Sindelar
mesh_terms: D001952:Bridged-Ring Compounds / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry*; D046911:Macromolecular Substances / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D043862:Rotaxanes / Q000138:chemical synthesis* / Q000737:chemistry; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils
chemical_list: D001952:Bridged-Ring Compounds; D002245:Carbon Dioxide; D007093:Imidazoles; D046911:Macromolecular Substances; D043862:Rotaxanes; C456276:cucurbit(7)uril; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils; C507198:cucurbit(8)uril; C041069:carboxyl radical