title: Can 1,3-dimethylcyclobutadiene and carbon dioxide co-exist inside a supramolecular cavity?
abstract: The calculated free energy barrier at 175 K between 1,3-dimethylcyclobutadiene and carbon dioxide inside a calixarene host (ωB97XD/6-311G(d,p)+polarizable continuum solvent model) has the low value of ~8-10.5 kcal mol(-1). This value casts doubt on the recently claimed isolation and X-ray structure determination at 175 K of 1,3-dimethylcyclobutadiene and carbon dioxide as separate species inside such a cavity.
authors.affiliation: Department of Chemistry, Imperial College London, South Kensington Campus, Exhibition Road, London, UK SW7 2AZ. rzepa@imperial.ac.uk
authors.forename: Henry S
authors.initials: HS
authors.lastname: Rzepa