Highly Anisotropic PdL L and PdL L Type Cages by Heteromeric Completive Self-Sorting.

Pd(II)-based low-symmetry coordination cages possessing anisotropic cavities are of great interest. The common strategies employed to achieve such cages utilize either more than one type of symmetrical ligands (e.g.

Cage-To-Cage Transformations in Self-Assembled Coordination Cages Using "Acid/Base" or "Guest Binding-Induced Strain" as Stimuli.

Controlling supramolecular systems between different functional forms by utilizing acids/bases as stimuli is a formidable challenge, especially where labile coordination bonds are involved. A pair of acid/base responsive, interconvertible 1,5-enedione/pyrylium based PdL-type cages are prepared that exhibit differential guest binding abilities towards disulfonates of varied sizes. A three-state switch has been achieved, where (i) a weakly coordinating base induced cage-to-cage transformation in the first step, (ii) a strongly coordinating base triggered cage disassembly as the second step, and (iii) the third step shows acid(strong) promoted generation of initial cage, thereby completing the cycle.

A Template-Free Pd L Cage with up to Nanomolar Affinity for Chloride in Aqueous Solutions.

Invited for the cover of this issue is the group of Dillip Kumar Chand at the Indian Institute of Technology Madras. The image depicts the efficient chloride binding ability of a designer self-assembled coordination cage in water. The binding occurs selectively even in presence of models of biologically abundant anionic systems.

A Template-Free Pd L Cage with up to Nanomolar Affinity for Chloride in Aqueous Solutions.

Selective binding of chloride over the other most abundant anions in living organisms is pivotal due to its essential role in physiological functions. Herein, we report a template-free Pd L cage exhibiting high selectivity for medium-sized halides (i. e.

Amide-Functionalized Chalcogen-Bridged Flexible Tetranuclear Rhenacycles: Synthesis, Characterization, Solvent Effect on the Structure, and Guest Binding.

The synthesis of flexible rhenium(I)-based amide-functionalized chalcogen-bridged tetranuclear metallacycles of general formula [{(CO)Re(μ-ER)Re(CO)}(μ-L)] () was achieved by treating rhenium carbonyl with dialkyl/diaryl chalcogenide (RE-ER; E = S and Se) in the presence of ditopic flexible or semiflexible pyridyl ligand with amide functionality (L = ,'-bis(4-pyridylcarboxamide)-1,2-ethane (bpce) and ,'-bis(4-(4-pyridylcarboxamide)phenyl)methane (bpcpm)). Compounds were formed by multicomponent self-assembly under one-pot reaction conditions via oxidative addition of dialkyl/diaryl chalcogenide to rhenium carbonyl with pyridyl ligands. The resultant metallacyclophanes were characterized using elemental analyses, infrared, ultraviolet-visible, and NMR spectroscopic techniques.