Reactivity of a Methylene‐Bridged 1,3‐Bis(germylene) in Dynamic Equilibrium with Its Dimer

Abstract

Abstract We report the properties and reactivity of an unprecedented methylene‐bridged 1,3‐bis(germylene) derivative. In the solid state, it undergoes dimerization to afford a 1,2,4,5‐tetragermacyclohexa‐1,4‐diene derivative (Ge 4 CHD). Moreover, theoretical calculations on Ge 4 CHD reveal σ*–π interactions between the two π orbitals (Ge═Ge) and the CH σ* orbital. This interaction is confirmed by a significant red shift in the solid‐state UV–vis spectrum. In contrast to the behavior in the solid state, the Ge 4 CHD derivative dissociates in solution into a methylene‐bridged 1,3‐bis(germylene) derivative. The resultant 1,3‐bis(germylene) derivative reacted with S 8 to form a novel cage compound containing three S and two Ge atoms. On the other hand, in the reaction with triphenylphosphine sulfide, the in situ generated 2‐thia‐1,3‐digermabicyclo[1.1.0]butane derivative activated the benzene solvent, leading to the formation of a [2 + 2] cycloaddition product. Additionally, the 1,3‐bis(germylene) derivative reacted with 4‐dimethylaminopyridine (DMAP) to form a three‐membered ring. Its structural parameters and the results of theoretical calculations indicated the zwitterionic character.