Rotaxane coordination polymers

ICP-MS = inductively coupled plasma mass spectrometry MIM = mechanically interlocked molecule MOF = metal organic framework MORF = metal-organic rotaxane framework PRF = polyrotaxane framework RCP = rotaxane coordination polymer TCPP = tetra 4-carboxy)-phenyl-porphyrin TGA = thermogravimetric analysis. 

Figure 10.71 Molecular necklace type coordination polymer rotaxanes (a) hexagonal 2D polyrotaxane net and (b) square-grid shaped 2D polyrotaxane net (reproduced by permission of The Royal Society of Chemistry).

Whang. D. Jeon. Y.-M. Heo, J. Kim. K. Self-assembly of a poly rotaxane contaning a cyclic bead" in every structural unit in the solid state Cucurbituril molecules threaded on a one-dimensional coordination polymer. J. Am. Chem. Soc. 1996, 118 (45). 11333-11334. 

Batten, S.R. Robson. R. Catenane and Rotaxane Motifs in Interpenetrating and Self-penetrating Coordination Polymers. In Molecular Catenanes, Rotaxanes and Knots, A Journey Through the World of Molecular Topology Sauvage, J.-P., Dietrich-Buchecker. C., Eds. Wiley-VCH Weinheim, 1999 77-105. 

Coordination polymers containing rotaxane linkers 12CSR5896. Design and synthesis of cross-Hnked poly(benzoxazine)- and polybenzimidazole-based copolymer membranes and their application to an electrolyte membrane for a high-temperature PEM fuel cell 13P77. 

S. R. Batten and R. Robson, Catenane and rotaxane motifs in interpenetrating and self-penetrating coordination polymers, in Molecular Catenanes, Rotaxanes and Knots, a Journey Through the World of Molecular Topology, eds. J.-P. Sauvage and C. Dietrich-Buchecka-, WUey-VCH Ver-lag GmbH, Weinheim, 1999, pp. 77-106. 

An example of a nontrivial polyrotaxane formed using a similar synthetic approach is shown in Figure 21(b). In this case, rotaxane ligands bridge cadmium ions into 2D (4,4) sheets, and the wheels (in this case dibenzo-24-crown-8) can no longer be separated from the polymeric network. Indeed, while the previous example contained only rotaxane motifs, in this nontrivial example one can also define catenane-type interactions between the wheels and M4L4 rings formed by the coordination polymer. 

Li+ salts with conservation of the rotaxanated topography. This was proved when Cu1 was nearly quantitatively reincorporated into the polyrotaxane. An X-ray absorption spectroscopy (XAS) study confirmed that the Cu1 is in a similar environment to model compounds, but that the symmetry of the coordination sphere is reduced due to steric constraints of the polymer matrix.71 Attempts to replace Cu1 with Co11 or Zn11 using the Li+ intermediate, or by electropolymerizing rotaxane 93 with Co11 or Zn11 in the place of Cu1 failed.72... 

There have been a considerable number of poly-rotaxanes reported in which the rotaxane motifs combine polymeric and discrete components. The most common of these involve preformed molecular rotaxanes acting as ligands, with the axle component containing coordinating groups at either end. Reaction of these rotaxane-based ligands with metals then gives polymeric structures. An example of a ID polymer constructed in... 

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