Electronic Configuration and Reactivity: First Semi-Quantitative Assessment of Relative Reactivities for the 3d Transition Metal Vapors Toward p-Bromotoluene in a Methylcyclohexane Solution

Abstract

A specifically designed metal vapor synthesis apparatus makes possible the semi-quantitative assessment of the reactivities for the elements of the first transition series toward p-bromotoluene kept in a -118°C solution of methylcyclohexane. In all cases, the two main processes are coupling and reduction of the substrate. The intrinsic reactivity of the substrate displays a behavior highly dependent upon the metal electronic configuration, suggesting a direct importance of the 18e rule in ruling these phenomena. Zn and Mn are the less reactive of the studied metals. In a way reminiscent of Rieke coupling of haloaromatics by metal powders, Ni vapor displays the highest ability in mediating the coupling of the substrate.