Dd2 500 mhz

H¹ NMR analysis for NAF, HPAF, and HDPAF unmodified and their modified derivatives was performed on a nuclear magnetic resonance spectrometer (Agilent Technologies, model DD2 500 MHz, CA, USA). Fifteen mg of sample and 500 μL of D₂O were used as a solvent in the unmodified fructans. While in the lauroylated, acetylated, and succinylated samples, CD₃OD, CD₃COCD₃ and D₂O were used as solvents, respectively. Spectral analysis and visualization were performed with MestReNova (Mestrelab Research. Chemistry Software Solutions. Version. 12.0.0-20080.2.2.2.3). The degree of substitution (DS) of the modified fructans was calculated as the ratio between the area under the peak at 0.8–1.2 ppm divided by three (assigned to the methylene protons) and the area under the signal of the glucosidic proton of glucose [5 (link)].

The compounds EuCl₃·6H₂O (99.9%, Aldrich) and 4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl)-1,3-hexanedione (hth) (Apollo Scientific), and the co-ligands dpso (97%, Aldrich), dpsoCH₃ (97%, Aldrich), dpsoCl (97%, Aldrich), and tppo (>98%, Fluka) were used without further purification. The NMR spectra of the complexes, in CDCl₃ (99.8%, Cambridge Isotope Labs) at 25 °C, were recorded on a Varian Mercury 400 MHz and on an Agilent DD2 500 MHz equipped with the OneNMR probe NMR spectrometers. The infrared spectra were recorded using a VERTEX 70v Bruker FT-IR spectrometer, examining powder samples in anhydrous KBr via diffuse reflection spectroscopy. Elemental analyses were carried out using a Thermo Scientific™ FLASH 2000 CHNS/O Analyzer at the Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara.

All commercially available chemicals of the appropriate purity were purchased from Merck (Kenilworth, NJ, U.S.A.) or Sigma ((St. Louis, MO, U.S.A.). The IR spectra were recorded on a Perkin Elmer Spectrum BX FT-IR spectrometer (Waltham, MA, U.S.A.). The ¹H NMR and ¹³C NMR spectra were recorded using a BRUKER Avance III-300 MHz (Billerica, MA, U.S.A.) or an AGILENT DD2-500 MHz ((Santa Clara, CA, U.S.A.) spectrometer. Chemical shifts were reported in δ (ppm) and signals were given as follows: s, singlet; d, doublet; t, triplet; m, multiplet. Melting points (mp) were determined with a MEL-TEMPII apparatus, Laboratory Devices, Sigma-Aldrich (Milwaukee WI, U.S.A) and were uncorrected. The microanalyses were performed on a Perkin-Elmer 2400 CHN elemental analyser (Waltham, MA, U.S.A.). Thin-layer chromatography (TLC silica gel 60 F₂₅₄ aluminium sheets, Merck (Kenilworth, NJ, U.S.A.) was used to follow the reactions and the spots were visualised under UV light.