Fig. 3: Variations of HO‑PBA dimer upon exposure to water.
From: Water-stable boroxine structure with dynamic covalent bonds
a Fluorescent spectra and intensity changes (at 316 and 368 nm, inset) of HO‑PBA dimer (2 × 10-5 mol L−1) in THF–water mixtures with different fractions of water (volume%), λex = 288 nm. b–e 1H (b, d) and 13C (c, e) NMR spectra of HO‑PBA dimer in THF−d8 (b, c) and in D2O–THF−d8 (2:1, v/v) mixture (d, e) at room temperature, concentration: 8 mg mL−1. f Fluorescent spectrum of 10-hydroxybenzo[h]quinolone (HBQ, 4.0 × 10-5 mol L−1) before (black) and after (red) addition of five molar equivalents of HO‑PBA dimer in a water–THF (4:1, v/v) solution, λex = 367 nm.
