title: Hydroxycruciforms: amine-responsive fluorophores.
abstract: The synthesis of three hydroxy-substituted cruciforms (XF, 1,4-bis(4'-hydroxystyryl)-2,5-bis(4''-methoxyphenylethynyl)benzene, 1,4-bis(4'-methoxystyryl)-2,5-bis(4''-hydroxyphenylethynyl)benzene, and 1,4-bis(4'-hydroxystyryl)-2,5-bis(4''-hydroxyphenylethynyl)benzene) starts with a Horner reaction followed by a Sonogashira coupling and subsequent deprotection. The three herein described XFs contain either two or four free phenolic hydroxyl groups. All three XFs were subjected to photometric UV/Vis titrations in a methanol/water mixture. The respective pK(a) values were obtained by data deconvolution. As the three XFs display a significant change in emission color upon photoinduced deprotonation, the XFs were taken up in different solvents and exposed to twelve amines. The amine-dependent change in emissivity of the tetrahydroxy XF is sufficiently distinct in the eight solvents that all of the inspected amines are discerned by a linear discriminant analysis. The tetrahydroxy XF in different solvents forms a sensor array, the response of which is based on the excited-state proton transfer (ESPT) to amines and mediated by the choice of the battery of solvents that are utilized.
authors.affiliation: School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA.
authors.forename: Psaras L
authors.initials: PL
authors.lastname: McGrier
authors.forename: Kyril M
authors.initials: KM
authors.lastname: Solntsev
authors.forename: Shaobin
authors.initials: S
authors.lastname: Miao
authors.forename: Laren M
authors.initials: LM
authors.lastname: Tolbert
authors.forename: Oscar R
authors.initials: OR
authors.lastname: Miranda
authors.forename: Vincent M
authors.initials: VM
authors.lastname: Rotello
authors.forename: Uwe H F
authors.initials: UH
authors.lastname: Bunz
mesh_terms: D000480:Alkynes / Q000138:chemical synthesis* / Q000737:chemistry; D000588:Amines / Q000737:chemistry*; D001555:Benzene Derivatives / Q000138:chemical synthesis* / Q000737:chemistry; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010636:Phenols / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013267:Stilbenes / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000480:Alkynes; D000588:Amines; D001555:Benzene Derivatives; D005456:Fluorescent Dyes; D010636:Phenols; D013267:Stilbenes