Dynamic Interconversion and Induced-Fit Guest Binding with Two Macrocycle-Based Coordination Cages.

We report the syntheses and host-guest chemistry of two interconvertible coordination cages, PdL and PdL, from a dynamic macrocycle ligand (L) and a cis-blocking (tmen)Pd(NO) (tmen = tetramethylethylenediamine) unit (Pd). The water-soluble macrocyclic L, which can bind various polycyclic aromatic hydrocarbon (PAH) guests in its cis-conformation, was constructed via four pyridinium bonds between two 2,4,6-tri(4-pyridyl)-1,3,5-triazine [TPT] panels and two -xylene bridges. We selectively formed each cage either by changing the reaction concentration/solvent/temperature or through induced-fit guest encapsulation, while direct assembly of L and Pd resulted in a mixture of PdL and PdL in equilibrium.

Shape Complementary Coordination Self-Assembly of a Redox-Active Heteroleptic Complex.

We present here the coordination self-assembly of a new heteroleptic coordination complex () from one novel pyridinium-functionalized bis-2,4,6-tris(pyridin-3-yl)-1,3,5-triazine (bis-3-TPT, ) macrocyclic ligand, two separate 3-TPT () ligands, and four -blocking bpyPd(NO) (bpy = 2,2'-bipyridine). While homoleptic self-assemblies with either or gave dynamic mixtures of products, a single thermodynamic heteroleptic complex was obtained driven by the shape complementarity of building blocks. Moreover, the redox-active nature of the heteroleptic assembly facilitates the highly efficient catalytic aerobic photo-oxidation of aromatic secondary alcohols under mild conditions.