Cage‐to‐Cage Cascade Transformations

Abstract

A series of Pd2 L4 -type binuclear self-assembled coordination cages (1-4), where L stands for a nonchelating bidentate ligand, were prepared. The strategies adopted for the synthesis of the cages were: combination of Pd(II) with 1) a selected ligand or 2) subcomponents of the ligand. Highly efficient cage-to-cage transformation reactions are demonstrated by suitable covalent modification (from 1 to 2 or 3 or 4) or ligand-exchange reactions (from 1 to 2 or 3 or 4; from 2 to 3 or 4). Thus, new cascade transformations (from 1 to 2 to 3; from 1 to 2 to 4) are achieved beautifully.

Transformation networks of metal–organic cages controlled by chemical stimuli

“…1a ). 58 The transformations are driven by the difference in strength of the Pd–N bonds, in the following order: amine–Pd < imine–Pd < pyridine–Pd. The introduction of four equivalents of ligand 6, 7 or 8 to a solution of cage 1 results in the release of ligand 5 together with the formation of cage 2, 3 or 4, respectively.…”

Self-assembled conjoined-cages

“…The processes of construction of coordination cages are sometime classified under narcissistic and integrative selfsorting 30,31 that are comparable to certain biological processes [32][33][34] . Dynamic behaviors of the coordination cages with respect to post-modifications such as cage-fusion reactions 35 and ligand-displacement-induced cage-to-cage transformations 36 are important studies of current interest. Construction of multi-3D-cavity cages, understanding related self-sorting processes and subjecting the cages to post-modifications are therefore attractive and fundamental aspects of supramolecular coordination chemistry.…”

Chemistry of Tetradentate [C,N : C,N] Iminophosphorane Palladacycles: Preparation, Reactivity and Theoretical Calculations

“…In a previous work we described formation of double Aframe complexes which could be accomplished by choosing an appropriate flexible bidentate Schiff base ligand, bis(N-2,3,4trimethoxybenzylidene)-4,4'-sulfonyldianiline, or -4,4'oxydianiline, [10] as opposed to the phenylenediimine-C,N : C,N analogues, where this was not possible, due to the restricted flexibility of the ligand imposed by the rigidness of the central phenylene ring itself, hindering opening of the metallacycle ring needed to provide the extra vacant coordination site on the metal for coordination of the second phosphine ligand. [11] These species are closely related to the field of supramolecular coordination complexes (SCCs), [13] and we found Scheme 2. Reaction sequence leading to the dinuclear and to the expected A-frame compounds.…”