‘Bowtie-shaped’ molecule displays spin entanglement

The first solution synthesis of the elusive ‘Clar’s goblet’ structure – first proposed over 50 years ago – has provided the perfect platform to prove spin entanglement between non-bonded electrons. Studying spin pairing at this scale could increase our understanding of quantum chemistry, as well as accelerate applications in quantum computing.

‘Clar’s goblet is a bowtie-shaped [structure] first proposed by Erich Clar in 1972,’ explains lead author Jishan Wu, from the National University of Singapore. ‘It’s characterised by the presence of two unpaired electrons, each […] localised in one half of the molecule.’ However, it’s precisely the unpaired electrons that make the molecule extremely unstable, and until now its synthesis in solution seemed impossible.