文摘
Pdb>3b>Lb>2b> metallo-cryptophane cages with cyclotriveratrylene-type L ligands can be stabilized by use of a bis-N-heterocyclic carbene as an auxiliary cis-protecting ligand, while use of more common protecting chelating ligands such as ethylenediamine saw a Pdb>3b>Lb>2b> to Pdb>6b>Lb>8b> rearrangement occur in solution. The crystalline Pdb>3b>Lb>2b> complexes act as sponges, taking up 1,2-dichorobenzene or iodine in a single-crystal-to-single-crystal fashion despite not exhibiting conventional porosity.