Remarkably stable self-assembled monolayers of new crown-ether annelated tetrathiafulvalene derivatives and their cation recognition properties†

Abstract

Bis-thioctic ester derivatives of crown-ether annelated tetrathiafulvalenes (TTFs) form extremely stable self-assembled monolayers (SAMs) on gold electrodes and can recognize alkali metal ions by cyclic voltammetry.

References

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8. All new compounds were fully characterized by spectroscopic techniques. Selected data for 1a: isolated as a red–orange solid in 87% yield, ν(KBr)/cm^–1 2932 (s), 1710 (vs), 1630 (vs), 1542 (s), 1163 (s); δ_H(CDCl₃/TMS) 4.91 (4H, s), 3.91 (4H, t, J 5.34), 3.74–3.67 (12H, m), 3.58 (4H, t, J 5.40), 3.19–3.14 (4H, m), 2.99 (2H, t, J 5.90), 2.45–2.37 (4H, m), 1.94–1.85 (2H, m), 1.79–1.63 (8H, m), 1.49–1.46 (4H, m); δ_C(CDCl₃) 173.70, 173.17, 154.47, 142.04, 129.92, 128.82, 111.84, 108.38, 71.98, 71.51, 70.38, 60.38, 58.37, 56.36, 40.62, 38.95, 37.05, 36.19, 34.17, 26.72, 25.07; λ_max(CHCl₃)/nm 327.5, 304.0; FAB⁺-MS: m/z 862 (M⁺, 60%), 864 (M⁺+ 2, 100%); HRMS (FAB⁺): m/z found 862.0453, calc. for C₃₂H₄₆O₇S₁₀: 862.0453. For data for 1b–d, see footnote †.
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12. All electrochemical experiments were performed using a BAS-100W system. Electrolyte solutions were prepared from recrystallized materials using spectroscopic grade solvents and purged with argon prior to use. A three-electrode configuration was used with a Ag/AgCl reference electrode and a platinum wire as the counter electrode. The geometric areas of the gold electrodes were calculated from the slopes of the linear plots of cathodic peak current vs. the square root of the scan rate obtained for the diffusion-controlled reduction of Ru(NH₃)₆³⁺[ref. 4(b)]. We employed a diffusion coefficient of 7.5 × 10^–6 cm² s^–1(at 25 °C in 0.1 M NaCl). Typical values for the geometric area of the electrodes varied from 0.01 to 0.02 cm². Surface coverages of the SAMs of TTF derivatives were calculated by integration of the current during the first scan.