Quenching of the Aromaticity of the 5-Dibenzo[a,d]cycloheptenylium Ion by Complexing with (CO)3Cr

✍ Scribed by Prof. Dr. Alberto Ceccon; Prof. Dr. Alessandro Gambaro; Dr. Annamaria Romanin; Dr. Alfonso Venzo

• Publisher: John Wiley and Sons
• Year: 1983
• Tongue: English
• Weight: 237 KB
• Volume: 22
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.198305591

✦ Synopsis

Some of the more electronegative transition metals can also be surface metallized by Zintl anions via a similar mechanism. Treatment of Pt foil with &Pb9 in en (24-48 h, 2S°C) gives lead crystals surrounded by a potassiumrich phase (XRD, SEM, EM/EDX). The potassium-rich phase is not present as K' as it retains considerable reducing power. Reaction of this K/Pb surface with reducible metal cations, like Pd2+, leads to deposition of the metal onto the surface to give a bimetallic surface, and K + goes into solution (Fig. 1 : 0). Other transition metal substrates (e.g. Au), and other Zintl anions and reducible metal cations can be used similarly to form many bimetallic surfaces. The second stage of the formation of these bimetallic surfaces, i. e. reduction of the cation M"+ (cf. Fig. 2b) can be viewed conceptually as the reverse of the oxidation of the Zintl anion M:-at a solid surface (Fig. 2a).