title: Molecular-recognition properties of a water-soluble cucurbit[6]uril analogue.
abstract: The molecular-recognition properties of the cucurbit[6]uril analogue (1) in aqueous buffer (sodium acetate, 50 mM, pH 4.74, 25 degrees C) toward a variety of guests including alkanediamines (6-12), aromatics (14-32), amino acids (33-36), and nucleobases (37-42) were studied by fluorescence spectroscopy. For the alkanediamines studied (H2N(CH)nNH2, n = 6, 7, 8, 9, 10, 11, 12), the association constants increase as the length of the alkane (n) is increased. Host 1 is capable of forming strong complexes with guests containing aromatic rings with association constants (Ka) ranging from 10(2) to 10(6) M(-1) as a result of the favorable pi-pi interactions that occur between host 1 and the aromatic rings of the guest when bound in the cavity of 1. Biologically relevant guests such as amino acids and nucleobases are also bound in the cavity of 1 with Ka values ranging from 10(3) to 10(6) M(-1). Consequently, cucurbit[6]uril analogue 1 functions as a versatile fluorescent sensor for the presence of a wide range of chemically and biologically important substances in aqueous solution including nitroaromatics, neurotransmitters, amino acids, and nucleobases.
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Lagona
authors.forename: Brian D
authors.initials: BD
authors.lastname: Wagner
authors.forename: Lyle
authors.initials: L
authors.lastname: Isaacs
mesh_terms: D000473:Alkanes / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D024322:Amino Acids, Aromatic / Q000737:chemistry / Q000378:metabolism; D000814:Aniline Compounds / Q000737:chemistry; D019817:Benzoic Acid / Q000737:chemistry; D001952:Bridged-Ring Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D018360:Crystallography, X-Ray; D004298:Dopamine / Q000737:chemistry / Q000378:metabolism; D006860:Hydrogen Bonding; D007093:Imidazoles / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D017672:Nitrogen Compounds / Q000737:chemistry; D019800:Phenol / Q000737:chemistry; D010851:Picrates / Q000737:chemistry; D012996:Solutions; D013050:Spectrometry, Fluorescence; D055672:Static Electricity; D014867:Water; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils
chemical_list: D000473:Alkanes; D000475:Alkenes; D000588:Amines; D024322:Amino Acids, Aromatic; D000814:Aniline Compounds; D019817:Benzoic Acid; D001952:Bridged-Ring Compounds; D004298:Dopamine; D007093:Imidazoles; D017672:Nitrogen Compounds; D019800:Phenol; D010851:Picrates; D012996:Solutions; D014867:Water; C454805:cucurbit(6)uril; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils; C005858:picric acid; C023650:aniline