Synthesis and Characterization of a Metallacyclic Framework with Three Fused Five‐membered Rings

Abstract

Polycyclic complexes containing abridgehead transition metal are interesting species because the transition metal is shared by all the rings simultaneously.I nt his study,w e present an ovel osmium-bridgehead system with three fused five-membered rings.T his novel framework can be viewed as a10-atom carbon chain coordinating to the osmium center.In sharp contrast to the nonplanar organic analogue,this unique metallacycle exhibits good planarity,w hich was unambiguously verified by means of X-rayd iffraction. Interestingly, preliminary DFT calculations show that the aromaticity in the three 5MRs of these osmatricycles can be easily tuned by the ligand substitution. Finally,t he broad UV/Vis absorption spectra of these novel polycyclic complexes were also reported. Angewandte ChemieCommunications 9069