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Multicomponent metallo-supramolecular assembly allows to rationally combine different building blocks. Discrete multifunctional hosts with an accessible cavity can be prepared in a non-statistical fashion. We employ our shape-complementary assembly (SCA) method to achieve for the first time integrative self-sorting of heteroleptic PdII cages showing guest-tunable circularly polarized luminescence (CPL). An enantiopure helicene-based ligand (M or P configuration) is coupled with a non-chiral emissive fluorenone-based ligand (A or B) to form a series of Pd2L2L’2 assemblies. The modular strategy allows to impart the chiral information of the helicenes to the overall supramolecular system, resulting in CPL from the non-chiral component. Guest binding results in a 4-fold increase of CPL intensity. The principle offers potential to generate libraries of multifunctional materials with applications in molecular recognition, enantioselective photo-redox catalysis and information processing., Angew Chem (Int Ed Engl);61(35)

A new series of [Pd2(L)4] cages based on photochromic dithienylethene (DTE) ligands allowed us to gain insight into the successive photoswitching of multiple DTE moieties in a confined metallo‐supramolecular assembly. Three new X‐ray structures of [Pd2(o‐L4)4], [Pd2(o‐L1)2(c‐L1)2] and [Pd2(c‐L1)4] (o‐L and c‐L = open and closed forms of DTE ligands, respectively) were obtained. The structures deliver snapshots of three different combinations of DTE photoisomeric states within the cage, facilitating a comparison of the all‐open with the all‐closed, and most notably, an intermediate form where open and closed switches co‐exist in the same cage. Moreover, a series of spherical anionic borate clusters was introduced in order to study their roles in the light‐controllable host–guest chemistry. The binding guests show higher affinities with the flexible open cage [Pd2(o‐L1)4] than with the rigid closed cage [Pd2(c‐L1)4]. For the [B12F12]2− guest, thermodynamic data obtained from NMR experiments was compared to results from isothermal titration calorimetry (ITC).

Host-guest chemistry is usually carried out in either water or organic solvents. To investigate the utility of alternative solvents, three different coordination cages were dissolved in neat ionic liquids. By using (19) F NMR spectroscopy to monitor the presence of free and bound guest molecules, all three cages were demonstrated to be stable and capable of encapsulating guests in ionic solution. Different cages were found to preferentially dissolve in different phases, allowing for the design of a triphasic sorting system. Within this system, three coordination cages, namely Fe4 L6 2, Fe8 L12 3, and Fe4 L4 4, each segregated into a distinct layer. Upon the addition of a mixture of three different guests, each cage (in each separate layer) selectively bound its preferred guest.

International audience; Cryptophanes are macropolycyclic cyclophanes constructed from two triply bridged concave cyclotriveratrylene analogues that encapsulate a large range of molecular and monoatomic substrates. Self-assembled metallo-organic cryptophanes based on M2+–carbonitrile (M = Pd or Pt) interactions have been obtained through the reactions of chiral nitrile-substituted cyclotribenzylenes (CTBs) 1 and 2 with [M(dppp)][OTf]2 (dppp = 1,3-bisdiphenylphosphinopropane, OTf = triflate) in 2:3 ratios in chlorinated solvents. The cryptophanes [Pd3(dppp)3(1)2]6+ and [Pd3(dppp)3(2)2]6+ were obtained exclusively in the chiral anti form in solution at room temperature whatever solvent was used; however the meso,syn form was identified as the major isomer of [Pd3(dppp)3(1)2]6+ at low temperature in CD2Cl2, and – in the case of [Pt3(dppp)3(1)2]6+ – it formed in a minor amount at room temperature. [Pd3(dppp)3(1)2][OTf]6 and [Pt3(dppp)3(1)2][OTf]6 crystallized in the anti forms with an encapsulated chloroform molecule, and gas-phase DFT calculations with the dispersion-corrected B97-D3 functional show that it is stabilized by 34.6 kJ mol–1. Interestingly, the heteroleptic cryptophane [Pd3(dppp)3(1)(2)]6+ was not detected in mixtures of [Pd(dppp)]2+ and CTBs 1 and 2 in a 3:1:1 ratio or through the equilibration of a 1:1 mixture of the preformed homoleptic cryptophanes; this points to favored self-sorting processes.