title: Probing the dimensions of semi-rigid inner functionalised U-shaped bis-porphyrin cavities.
abstract: The synthesis of a series of open U-shaped bis-porphyrin cavity molecules is described, with bridged bicyclic backbones to confer rigidity, and a pendant substituted aromatic probe unit suspended on the inside of the cavity. The dimensions and flexibility of the bis-zincporphyrin cavity were probed using several different techniques. Initially the molecular ruler concept was employed, using flexible bidentate ligands as guests with a range of possible linear dimensions. Secondly, NMR methods were employed with rigid bidentate ligand guests of fixed lengths, and thirdly diffusion based NMR methods were utilised. The range of inter-porphyrin distances estimated by these methods suggests that these types of open-cavity systems have a surprising degree of flexibility.
authors.affiliation: Chemistry, School of Biological, Biomedical and Molecular Sciences, University of New England, Armidale, NSW 2351, Australia.
authors.forename: Shaun P
authors.initials: SP
authors.lastname: Gaynor
authors.forename: Maxwell J
authors.initials: MJ
authors.lastname: Gunter
authors.forename: Martin R
authors.initials: MR
authors.lastname: Johnston
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Warrener
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D011166:Porphyrins / Q000737:chemistry*
chemical_list: D011166:Porphyrins