New Molecular Clips from Diphenylglycoluril and Catechol: Preparation, Structure and Conformation Studies, Binding Properties

Abstract

A new molecular clip and its two alkylated derivatives, which are soluble in most of organic solvents, were prepared from hydroxymethylated diphenylglycoluril and catechol. The structure and conformation of these new clips were studied. Their binding properties for dihydroxybenzene were also studied with the aid of ¹H NMR titration.

Keywords

diphenylglycoluril - molecular clip - supramolecular assemblies - catechol

References

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8

Compound 3a: ¹H NMR (300 MHz, DMSO-d ₆): δ = 9.37 (s, 2 H, OH) and 8.32 (s, 2 H, OH), 7.08 (s, 10 H, ArH), 6.97 (d, 2 H, ArH, J = 8.4 Hz) and 6.48 (d, 2 H, ArH, J = 8.4 Hz), 5.36 and 3.59 (d, 4 H, ArCH₂N, J = 15.9 Hz), 4.50 and 3.91 (d, 8 H, ArCH₂N, J = 15.9 Hz). ¹³C NMR (75 MHz, DMSO-d ₆): δ = 159.50, 159.06 (urea C=O), 145.24, 143.71, 138.47, 134.90, 134.33, 128.64, 128.53, 128.35, 128.17, 125.18, 113.30, 85.25, 78.73, 45.76, 45.34, 44.94, 37.05. ESI-MS (FAB): m/z = 563 [M + H]⁺; mp >294 °C. Compound 3b: ¹H NMR (CDCl₃): δ = 7.08 (s, 10 H, ArH), 6.69 (d, 2 H, ArH, J = 8.4 Hz) and 6.63 (d, 2 H, ArH, J = 8.4 Hz), 5.54 and 3.80 (d, 4 H, ArCH₂N, J = 15.9 Hz), 4.72 and 4.09 (d, 4 H, ArCH₂N, J = 15.9 Hz), 3.91 (s, 6 H, OCH₃) and 3.78 (s, 6 H, OCH₃). ¹³C NMR (75 MHz, CDCl₃): δ = 157.70, 157.27 (urea C=O), 151.98, 146.58, 133.80, 131.14, 130.09, 128.73, 128.32, 128.25, 124.98, 110.55, 85.63, 62.50, 61.56, 60.79, 56.31, 56.07, 46.00, 45.78, 38.10. ESI-MS (FAB): m/z = 619 [M + H]⁺; mp >294 °C. Compound 3c: ¹H NMR (CDCl₃):
δ = 7.08 (s, 10 H, ArH), 6.91 (d, 2 H, ArH, J = 8.4 Hz) and 6.59 (d, 2 H, ArH, J = 8.4 Hz), 5.59 and 3.76 (d, 4 H, ArCH₂N, J = 15.9 Hz), 4.70 and 4.08 (d, 4 H, ArCH₂N, J = 15.9 Hz), 4.13 (q, 4 H, OCH₂C, J = 10.9 Hz), 3.96 (q, 4 H, OCH₂C, J = 10.9 Hz), 1.47-1.37 (br, 12 H, OCCH₃). ¹³C NMR (75 MHz, CDCl₃): δ = 158.07, 157.68 (urea C=O), 151.67, 146.49, 134.17, 131.31, 130.19, 128.78, 128.71, 128.51, 128.41, 124.79, 111.68, 85.48, 69.45, 64.17, 45.50, 37.83, 16.06, 15.22. ESI-MS (FAB): m/z = 675 [M + H]⁺; mp 227.4-228.1 °C.