Self-assembled calix[4]arenequinhydrone on the platinum electrode by cathodic reduction of calix[4]arenediquinone

Abstract

The electrochemical reduction of di(methoxyp-tert-butyl)calix [4]arenediquinone led to its calix[4]arenedihydroquinone. The presence of both in the solution refers to the generation of calix[4]arenequinhydrone charge-transfer complex at the electrode surface through a donor/acceptor process type. Self-assembled adlayers of calix[4]arenequinhydrone was obtained by partial electrochemical reduction. Electrochemical deposition of the last form was achieved on the platinum disk electrode at -1.16 V versus SCE (saturated calomel electrode) in aprotic solution by cathodic reduction of the starting substrate. The deposit was first characterized by cyclic voltammetry (CV) in electrolytic solution and then in electrolyte support solution and finally in a ferricyannure solution. The self-assembled product was characterized by MALDI-TOF Mass and IR spectroscopy techniques. It was observed too by SEM technique. Calix[4]arenequinhydrone is observed on the electrode surface as hexangular prisms with a length of few micrometers.

One Step Synthesis of Calix[n]quin­ones through the HClO4/PbO2‐Mediated Oxidation of Calix[n]arenes

“…This first series of results shows that the PbO 2 /HClO 4 -mediated oxidation can efficiently lead to calixquinones in one step from (p-tBu-)calix[n]arenes. In the case of compounds 1Q, 4Q, and 5Q, the yields are similar or higher than those previously reported with thalium(III) salts (14, [4a] 79, [8] and 19 %, [9] respectively). It is noteworthy that compound 3Q was not reported previously.…”

“…Spectral data are in accordance with the literature. [8] R f [CH 2 Cl 2 /acetone (98:2, v/v)] = 0.42. -1,3,5-trimethyl-2,4,6-trisquinone 5Q: The general procedure was used on 300 mg of 5 (0.295 mmol).…”

Electrochemical and spectral studies of auto-assembled arrays of calix[4]arenequinhydrone charge-transfer complex on indium–tin oxide (ITO) glass

“…2 ) (300 Hz, CDCl 3 ): δ (ppm) 1.34 [s, 18H, C(CH 3 ) 3 ]; 3.10 [s, 6H, OCH 3 ]; 3.32 [br s, 4H, ArCH 2 Ar]; 3.78 [br s, 4H, ArCH 2 Ar]; 6.32 [s, 4H, QuH]; 7.22 [s, 4H, ArH]. The schematic pathway of synthesis of the X 4 Me 2 Q 2 has been reported in our previous work [ 25 ].

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“…The presence of both in the solution refers to the generation of calix[4]arenequinhydrone charge-transfer complex at the electrode surface through a donor/acceptor process type. Self-assembled adlayers of calix[4]arenequinhydrone was obtained by partial electrochemical reduction on the platinum electrode [25]. The calix[4]arenequinhydrone was obtained too in acetonitrile solution, by partial electrochemical oxidation of the calix[4]arenedihydroquinone [26].…”

“…In our preceding work, we show that the electrochemical reduction of di(methoxy- p - tert -butyl)calix[4]arenediquinone led to the corresponding calix[4]arenedihydroquinone [ 25 ]. The presence of both in the solution refers to the generation of calix[4]arenequinhydrone charge-transfer complex at the electrode surface through a donor/acceptor process type.…”