Synthesis and isolation of a triplet bismuthinidene with a quenched magnetic response

Large spin-orbit coupling (SOC) is an intrinsic property of the heavy elements that directly affects the electronic structures of the compounds. In this work, we report the synthesis and characterization of a monocoordinate bismuthinidene that features a rigid and bulky ligand. All magnetic measurements [superconducting quantum interference device (SQUID), nuclear magnetic resonance (NMR)] point to a diamagnetic compound. However, multiconfigurational quantum chemical calculations predict the ground state of the compound to be dominated (76%) by a spin triplet. The apparent diamagnetism is explained by an extremely large SOC-induced positive zero-field splitting of more than 4500 wavenumbers that leaves the MS = 0 magnetic sublevel thermally isolated in the electronic ground state.

Automated summary

In this work, the synthesis and characterization of a monocoordinate bismuthinidene compound with a rigid and bulky ligand were reported. Despite showing diamagnetic properties in all magnetic measurements, multiconfigurational quantum chemical calculations revealed that the compound's ground state is dominated by a spin triplet. The apparent diamagnetism is explained by an extremely large spin-orbit coupling-induced positive zero-field splitting.