Gold(III) Diazonium Complexes for Electrochemical Reductive Grafting

Abstract

Gold(III) diazonium complexes were synthesized for the first time and studied for electrochemical reductive grafting. The diazonium complex [CN-4-C(6)H(4)N≡N]AuCl(4) was synthesized by protonating CN-4-C(6)H(4)NH(2) with chloroauric acid H[AuCl(4)]·3H(2)O to form the ammonium salt [CN-4-C(6)H(4)NH(3)]AuCl(4), which was then oxidized by the one-electron oxidizing agent [NO]PF(6) in CH(3)CN. The highly irreversible reduction potential of 0.1 mM [CN-4-C(6)H(4)N≡N]AuCl(4) observed at -0.06 V versus Ag/AgCl in CH(3)CN/0.1 M [Bu(4)N]PF(6) encompasses both gold(0) deposition and diazonium reduction. Repeated scans showed the absence of the reduction peak on the second run, which indicates that surface modification with a blocking gold aryl film has occurred and is largely complete.

Functionalization of nanomaterials with aryldiazonium salts

“…Overton and Mohamed [45] have been recently able, for the first time, to synthesize stable diazonium tetrachloroaurate(III) complexes [R-4-C 6 H 4 N≡N]AuCl 4 (R = CN, C 8 F 17 , Br, NO 2 , F, C 6 H 13 ) in a high yield (Fig. 18) A single-phase synthesis of organometallic gold nanoparticles was reported in a recent communication [155].…”

Synthesis of Diazonium Tetrachloroaurate(III) Precursors for Surface Grafting

“…Structures 1-3 have been reported in reference [39]. X-ray structure of 5 is shown in Figure 3 and X-ray data is presented in Table 1.…”

“…The tetrachloroauric(III) acid based procedure can be utilized in preparation of a wide range of diazonium compounds in organic solvents without the need for mineral acids (Scheme 1) [39]. Protonation of CN-4-C 6 …”

“…The synthesis of gold complexes of potential applications in materials chemistry is a rising field of interest [38,39]. We describe a facile procedure for the synthesis of stable diazonium tetrachloroaurate(III) complexes.…”

“…We describe a facile procedure for the synthesis of stable diazonium tetrachloroaurate(III) complexes. Preliminary results on the synthesis and grafting have been reported in a communication to Inorganic Chemistry [39]. …”