Constructions of two polycatenanes and one polypseudo-rotaxane by discrete tetrahedral cages and stool-like building units

Abstract

Mechanically Interlocked molecules, such as catenanes and rotaxanes, are of great interest due to their fascinating structures and potential applications, while such molecules have been mainly restricted to comprising components of interlocked rings or polygons. The constructions of infinite polycatenanes and polyrotaxanes by discrete cages remain great challenge, and only two infinite polycatenanes fabricated by discrete cages have been reported so far, while the structures of polyrotaxanes and polypseudo-rotaxanes fabricated by discrete build units have not been documented to date. Herein we report the first example of a two-dimensional (2D) polypseudo-rotaxane fabricated by stool-like build units, the second example of a one-dimensional (1D) polycatenane, and the second example of a three-dimensional (3D) polycatenane, which were assemblied by discrete tetrahedral cages. The pores of dehydrated 3D polycatenane are dynamic, and display size-dependent adsorption/desorption behaviors of alcohols.

Interpenetrated Cage Structures

“…Another example of partially interlocked cages was reported by Lu and co‐workers in 2012 . They reported a tetrahedral cage comprising of tri(4‐carboxybenzyl)amine (H 3 tcba) ligands 45 and Ni 2+ ions, which were protected by 1,4,8,11‐tetraazaundecane (L; Figure a).…”

Controllable Coordination Self‐Assembly Based on Flexible Tripodal Ligands: From Finite Metallocages to Infinite Polycatenanes Step by Step

“…It is worthwhile to note that some of these assembly processes are The balland-stick representation of a 3D polycatenane assembled from discrete interlocked tetrahedral cages. [66] Copyright V C 2013, rights managed by Nature Publishing Group. 4 cage units have been synthesized (Scheme 4c), which may be ascribed to the following factors: (1) the suitable windows and large cavity from the cages can satisfy the multiple interlocking; (2) the strong charge-charge interactions from anions and positive frameworks make the interlocking knots stable.…”

“…[66] As shown in Figure 27, four tcba 32 anions connect six Ni(tad) 21 cations through their three 4-carboxybenzyl groups to form a tetrahedral cage of [Ni(tad)] 6 (tcba) 4 , in which each Ni(II) is six-coordinated by four N atoms from tad and two carboxylate O atoms from two individual tcba 32 anions, and each tcba 32 connects three Ni(tad) 21 . Four tcba 32 locate at four vertices of the tetrahedral cage, and six Ni(II) locate at the six edges of the tetrahedral cage.…”

“…In fact, two other intriguing structures with mechanical bonds have also been constructed from this flexible ligand L 33 by Lu and co-workers. [66] Very recently, Hong and colleagues have used very flexible ligands L 34 (time) and silver salts to assemble two different infinite 1D polycatenanes based on discrete M 6 L 4 metallocages. [67] 61 metallocage (all of these cages have similar topological structures), as shown in Scheme 3a, then these cages can further assemble into different infinite motifs.…”

Construction of a metal–organic framework by octuple intercatenation of discrete icosahedral coordination cages

“…5 30 The third one by another Lu (T. B. Lu) and co-authors represented the second example of extended 3-D polycatenated structure built by quadruple intercatenation of discrete tetrahedral coordination cages. 6 Herein, we report the synthesis and structure of a rare 3-D polycatenated architecture, 35 Pb 13 (BTTC) 8 Compound 1 was obtained by solvothermal reaction of H 3 BTTC (Benzo-(1,2;3,4;5,6)-tris(thiophene-2'-carboxylic acid)) 60 ligand and Pb(NO 3 ) 2 in DMA solvent. The formula of 1 was determined to be Pb 13 (BTTC) 8 (OH) 2 (H 2 O) 4 .…”