title: Water-soluble cruciforms and distyrylbenzenes: synthesis, characterization, and pH-dependent amine-sensing properties.
abstract: Three water-soluble fluorescent aldehyde-substituted distyrylbenzene derivatives were prepared using Heck or Horner methodologies. Water solubility was achieved through the addition of branched oligoethylene glycol side chains; these are attached via an ether bridge to the aromatic nucleus. The aldehydes are almost nonfluorescent in water, but addition of primary amines turns the fluorescence on; formation of imines results. Control of the basicity of the media allows further discrimination of the analytes employed. 1,3-Diaminopropane reacts with these aldehydes. Instead of an imine, a brightly fluorescent aminal forms. Amino acids are almost always nonreactive toward these aldehydes. Exceptions are lysine and cysteine, which form an imine and a thioaminal, respectively, discreating the aldehyde unit under fluorescence turn-on in water. The detection limit and time of completion of the sensing event were evaluated. Dialdehydes 3 and 16 were comparable on both counts. The cross-shaped 16 did react approximately twice as quickly with 1,3-diaminopropane.
authors.affiliation: Organisch-Chemisches Institut, Ruprecht-Karls Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Freudenberg
authors.forename: Jan
authors.initials: J
authors.lastname: Kumpf
authors.forename: Vera
authors.initials: V
authors.lastname: Schäfer
authors.forename: Eric
authors.initials: E
authors.lastname: Sauter
authors.forename: Svenja J
authors.initials: SJ
authors.lastname: Wörner
authors.forename: Kerstin
authors.initials: K
authors.lastname: Brödner
authors.forename: Andreas
authors.initials: A
authors.lastname: Dreuw
authors.forename: Uwe H F
authors.initials: UH
authors.lastname: Bunz
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D000588:Amines / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D012995:Solubility; D013343:Styrenes / Q000138:chemical synthesis* / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D000447:Aldehydes; D000588:Amines; D013343:Styrenes; C507243:distyrylbenzene; D014867:Water