biostudies-literatureUchida DJapan Science and Technology AgencyJapan Society for the Promotion of Sciencee202508927https://www.ebi.ac.uk/biostudies/studies/S-EPMC12363641biostudies-literatureUnknown64(34)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 (Ge₄CHD). Moreover, theoretical calculations on Ge₄CHD 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 Ge₄CHD derivative dissociates in solution into a methylene-bridged 1,3-bis(germylene) derivative. The resultant 1,3-bis(germylene) derivative reacted with S₈ 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.Angewandte Chemie (International ed. in English)Reactivity of a Methylene-Bridged 1,3-Bis(germylene) in Dynamic Equilibrium with Its Dimer.PMC1236364125H02026JPMJFS212324K0149619H0563518H0196322K14665Mizuhata YYamauchi MTokitoh NYukimoto MYamada HUchida DfalseReactivity of a Methylene-Bridged 1,3-Bis(germylene) in Dynamic Equilibrium with Its Dimer.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 (Ge₄CHD). Moreover, theoretical calculations on Ge₄CHD 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 Ge₄CHD derivative dissociates in solution into a methylene-bridged 1,3-bis(germylene) derivative. The resultant 1,3-bis(germylene) derivative reacted with S₈ 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.2025-01-01T00:00:00Z2025 Aug2026-05-01T01:42:50.444Z2026-04-07T16:33:25.646ZS-EPMC123636414054594910.1002/anie.202508927