Using a New Pt(II) Source to Make Pt(II) Lantern‐Shaped Cages, Including Low‐Symmetry, Heteroleptic, and Multicavity Examples

Abstract Current synthetic methods towards Pt(II) lantern‐shaped cages involve the use of dry solvent, inert atmosphere, lengthy reaction times, and highly variable yields if isolated. Starting materials such as [Pt(CH 3 CN) 4 ](BF 4 ) 2 suffer from a poor shelf‐life, reducing the synthetic accessibility of various Pt(II) architectures. A new Pt(II) source (with varied counterions), [Pt(3‐ClPy) 4 ](X) 2 (3‐ClPy=3‐chloropyridine, X=BF 4 − , OTf − , NO 3 − ), is developed and characterised, showing greatly enhanced shelf‐life characteristics under ambient atmospheric conditions. Using this starting material, the assembly of Pt(II) lantern‐shaped cages was completed in as little as 1.5 hours with wet solvent and ambient atmosphere. The first examples of low‐symmetry, heteroleptic and multicavity Pt(II) lantern‐shaped cages are reported using this approach. Attempts towards an M 6 L 8 octahedron using a tritopic ligand instead generate an interesting M 2 L 4 cage with unbound pyridyl arms. Ligands and cages are characterised by NMR spectroscopy, IR spectroscopy, mass spectrometry, and X‐ray crystallography in some cases.