Palladium‐Templated Subcomponent Self‐Assembly of Macrocycles, Catenanes, and Rotaxanes

Abstract

The reaction of 2,6-diformylpyridine with diverse amines and Pd(II) ions gave rise to a variety of metallosupramolecular species, in which the Pd(II) ion is observed to template a tridentate bis(imino)pyridine ligand. These species included a mononuclear complex as well as [2+2] and [3+3] macrocycles. The addition of pyridine-containing macrocyclic capping ligands allows for topological complexity to arise, thereby enabling the straightforward preparation of structures that include a [2]catenane, a [2]rotaxane, and a doubly threaded [3]rotaxane.

Salt‐Induced Adaptation of a Dynamic Combinatorial Library of Pseudopeptidic Macrocycles: Unraveling the Electrostatic Effects in Mixed Aqueous Media

“…The binarym ixtures formed from the mixture of an eutral and ac harged BB have constantsw ith values between 0.04 and 0.2 (Table 1, entries 4-11), indicating that the heterodimers are slightly favored in front of the homodimers. Finally,t he binary mixtures formedb yapositivelya nd an egatively charged BB have constants with values 0.002 (Table 1, entries [12][13][14][15], indicating that the heterodimers are much more stable than the homodimers (! 15 kJ mol À1 ).…”

“…This perspective has recently changed after the eruption of systems chemistry [5] as an emerging discipline at the interphase of chemical, physical, and biological sciences. In this regard, dynamic chemical systems (dynamic libraries) [6] can be used as am ethodological tool for the optimization of receptors, [7] sensors, [8] catalysts, [9] and transporters, [10] as ligands for biomolecules, [11] for the preparation of complex unexpected molecular structures, [12] or even as modelso fp rebiotic molecular behaviors.…”

Ion‐Mobility Mass Spectrometry for the Rapid Determination of the Topology of Interlocked and Knotted Molecules

“…Thelibrary PyCat contained amacrocycle (0 1 1 L,s ee structure in Figure S31 in the Supporting Information), aP d II -templated [2]catenate (2 2 1 PyCat), and a [3]catenate (4 3 1 PyCat). [25] ThePd II -templated [3]catenate ion 4 3 1 PyCat ÂÃ 4þ has twice the mass and twice the charge of the Hopf link 2 2 1 PyCat ÂÃ 2þ and, therefore,could not be separated solely based on the m/z value.H owever,i nT WIMS these species were well separated (Supporting Information , Figure S29) and were subjected to CID separately.H ere,t he positive charges are carried by the palladium cation coordinated inside the catenate;h ence,p redicting fragmentation pathways for these structures is more difficult. ForHopf link 2 2 1 PyCat ÂÃ 2þ ,w eobserved as elective cleavage of one of the rings together with ac harge-transfer reaction (Supporting Information, Figure S29).…”

Using Complementary Ligand Denticity to Direct Metallosupramolecular Structure about Metal Ions with Square‐Planar Geometry

“…Nitschke and coworkers have also reported a recent 1 , 3 system using imine coordination chemistry. The 1 : 1 : 1 combination of 2,6‐diformylpyridine and benzidine with Pd II in acetonitrile gave rise through imine condensation to an equilibrium mixture of tris ‐tridentate ( L28 ) and tetra ‐tridentate ( L29 ) macrocycles, [Pd 3 L28 (CH 3 CN) 3 ] 6+ and [Pd 4 L29 (CH 3 CN) 4 ] 8+ (Figure ) . They sought to induce quantitative product formation using appropriate poly‐ monodentate ligands as central templates.…”