Copper -templated threading

Figure 2.25. Copper(I)-templated threading of macrocycle 58 onto 1,10-phenanthroline-based molecular threads containing two such chelates 59, 60, 61, and 62, to afford threaded complexes 63, 64, 65, and 66 respectively.

Figure 30 Copper(I)-templated threading of macrocycle (73) onto 1,10-phenanthroline-...

Figure 31 Assembly, by copper(I)-templated threading, of two zinc porphyrins appended to...

Figure 32 Assembly, by copper(I)-templated threading, of a zinc(II) poq>hyrin (82) and a gold(III) porphyrin (89) appended to a chelating macrocycle. The bis-chelate molecular thread (85) affords complexes (90), (91), and (92) [123].

Figure 33 Construction of stacks of macrocycles by the copper(I)-templated threading strategy. Two macrocyclic units (73) are threaded onto the rigid bis-chelate rods (93) and (94), affording complex assemblies (95) and (96) [124, 125].

Stacks of macrocycles were obtained by Lehn and coworkers, by using rod-shaped bis-bipyridine linear components [124, 125], An example is shown in Figure 33 copper(I)-templated threading of two molecules of macrocycle (73) onto the molecular rods (93) or (94) produced the rigid rack assemblies (95) and (96), in which the two threaded macrocycles display the same orientation with respect to the rod component. The use of a sexipyridine ligand allowed for the copper(I)-controlled threading of three macrocycles (equation (c) of scheme 8). 

Figure 2.28. Copper(I)-templated synthesis of [2]-rotaxane 81 from the thread 77, macrocycle 58, and Ru(II)-complex precursor 79.

Figure 232. Copper(I)-templated synthesis of Cu(I)-complexed [2]-rotaxane 96 whose thread contains a terpyridine and a phenanthroline chelate.

Figure 51 Principle of transition metal-templated synthesis of a [3]-rotaxane, from two chelating macrocycles (B) and a bis-chelate-containing molecular thread (A) functionalized with reactive end groups X (same conventions as in Figure 43). (ii) Threading step, affording prerotaxane (C) construction of the porphyrin stoppers providing copper(I)-complexed [3]-rotaxane (D).

The target Cu(l)-complexed [2]catenane contains two different macrocycles. Therefore, two routes can be envisaged for its construction by the transition metal templated strategy [64]. They are shown in Fig. 17. Both involve the preparation of an intermediate precatenane species, (C) or (F), in which either Zn or Au porphyrin-containing macrocycle (A) or (E) is threaded onto chelate (B), thanks to copper(I) coordination. Formation of the second, inter-... 

A very interesting rotaxane bearing two Cgo stoppers was prepared from a well-established method developed by Dietrich-Buchecker and Sauvage, which consists of coupling a macrocycle and a thread, both presenting phenantroline systems and employing copper(l) as a template (Figure 2.18). This system showed relevant differences in the electrochemical, spectroscopic, and photophysical properties when compared to pristine Cgg. 

ABSTRACT. Knots and interlaced designs have been part of human artistry and culture since the earliest times. In chemistry, knots have been the focus of theoretical investigations for several decades. In pandlel, a few experimental approaches have been attempted by synthetic chemists. Until recent years, the only preparative routes pursued used the tools of classical organic chemistry. Despite their intellectual elegance, they have not succeeded. By taking advantage of the three-dimensional template effect of a transition metal (copper I), it has recently been possible to interlace two molecular threads prior to cyclisation and formation of a dimetallic trefoil knot. The demetallated knotted molecule and its di-copper(I) precursor have been fully characterized and studied. The X-ray structure of the dimetallic trefoil knot has been solved. It confirms the topology of the system. 

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