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.

A Cruciform Electron Donor–Acceptor Semiconductor with Solid‐State Red Emission: 1D/2D Optical Waveguides and Highly Sensitive/Selective Detection of H2S Gas

“…Such motifs allow the gradual tuning of inter‐ and intramolecular interactions, which render them appealing in the development of dual‐ and even multi‐functional materials. For instance, Bunz and coworkers reported three water‐soluble and fluorescent aldehyde‐substituted distyrylbenzene derivatives with a cruciform structure, showing pH‐dependent amine‐sensing properties …”

Stable Activated Furan and Donor–Acceptor Stenhouse Adduct Polymer Conjugates as Chemical and Thermal Sensors

“…The detection of amine-containing compounds is attractive for various industrial and research applications including chemical synthesis and environmental monitoring. − In particular, applications such as food spoilage and on-site water contamination benefit from the use of water as a “green” solvent for sensing. − To date, the degradation and spontaneous cyclization of the colored, triene form of DASA adducts in water has limited their utility as aqueous sensors, while the inability to covalently attach the activated furan to solid supports has led to unacceptable levels of leaching. To demonstrate the utility of these activated furan polymers as a broad platform for sensing, a spin-coated film of 12 was prepared on a precleaned cover glass slip to produce a transparent film (∼1 μm).…”

Acidochromic Turn‐on 2,4‐Diarylpyrano[2, 3‐b]indole Luminophores with Solubilizing Groups for A Broad Range of Polarity

“…For increasing the hydrophilicity in the coupling partner, we reasoned that a p ‐alkoxy substituted phenylacetylene bearing a polar “swallowtail” (SWTp), i. e. an oligo(ethylene glycol) (2,5,8,11,15,18,21,24‐octaoxapentacos‐13‐yl) side chain, should meet this criterion. Starting from p ‐iodophenol the alkyne 4 a was synthesized in three steps by Williamson etherification, alkynylation with (trimethylsilyl)acetylene, and desilylation in methanol/NaOH (aq.) (for experimental details see Supp Inf).…”