Dinaphtho crown

Other supramolecular structures such as catenanes and rotaxanes can be formed using zinc as a template ion for example, a benzylic imine catenate formed by Leigh et a/.288 The reversible five-component assembly of a [2]catenane from a chiral metallomacrocycle and a dinaphtho-crown ether has been achieved. Zinc is used as the metal component and drives assembly via the coordination to a bipyridyl unit 7r interactions between the aromatic components are also... 

Try AC, Harding MM, Hamilton DG, Sanders JKM, Reversible five-components assembly of a [2]catenane from a chiral metallomacrocycle and a dinaphtho-crown ether, Chem. Commun., 723-724, 1998. 

Bria et al. synthesized a tetracationic cyclophane-aromatic crown ether-type side-chain poly[2]catenane 59 by employing click chemistry, via route iii (Scheme 17.18) [111]. First, the template-directed coupling reaction between bis(bipyridinium) salt 28 and the alkyne-substituted p-xylylene dibromide 55, in the presence of dinaphtho crown ether 54, afforded an alkyne-functionalized [2]catenane 56 [112], Substitution of the chloro group on styrene-vinylbenzyl chloride copolymer 57 (M = 3.7 kDa, M , = 6.3 kDa) with sodium azide gave the azide-functionalized polymer 58 [83,113-115]. By employing CuS04/ascorbic acid as catalyst [116-120], click chemistry between azide-functionaUzed polymer 58 and alkyne-functionalized [2]catenane 56 afforded the side-chain poly[2]catenane 59, the successful formation of which was confirmed with Fourier transform infrared (FTIR) and NMR analyses. Unfortunately, both of these techniques revealed that the reaction of the azide groups was incomplete, and the observation was ascribed to a Coulombic repulsion of the cyclophane units and steric hindrance caused by the bulky catenane units[121]. 

Scheme 1.4 An electron-rich dimethoxybenzene template was used to direct the synthesis of a naphthalenediimide-based macrocycle 4 [21]. Addition of dinaphtho-crown ether 6 led to the formation of [2]catenane 5 [22].

Figure B. Pictorial representation of the self-assembly of pseudorotaxa-nes based on (a) charge-transfer and C-H—O hydrogen-bonding interactions between 1,1 -diben-zyl-4,4 -bipyridinium dication and 1,5-dinaphtho[38] crown-10 (1/5DN38C10), and (b) hydrogen-bonding interactions between dibenzyl ammonium ion and dibenzo[24]crown-8 (DB24C8). A possible route towards the synthesis of rotaxanes and catenanes is also schematized.

Figure 5.4 X-Ray structure of [2]-catenane formed between l,5-dinaphtho-3S-crown- 0 and 6 6 shaded in blue in the space-filling representation ...

In contrast, when a larger tetracationic cyclophane ring was employed in another set of experiments, the formation of new [3]-catenanes was found to be more facile. ° The expanded ring was obtained by replacing the phenylene linker units in the normal tetracationic cyclophane with biphenylene units. This larger ring was found to form readily around two threaded crowns when the latter are present in the acetonitrile reaction mixture in several-fold excess. Both bis-p-phenylene-34-crown-lO and l,5-dinaphtho-38-crown-10 were successfully employed in separate reactions to produce the corresponding [3]-catenanes in 20 and 31% yields, respectively. 

Examples are the 1, l -dibenzyl-4, 4 -bipyridinium electron-acceptor dication threaded into the 1, 5-dinaphtho-38-crown-10 (Fig. 2a) [10], and the acyclic polyether containing a dioxybenzene electron-donor unit threaded into the electron-acceptor cyclobis(paraquat-p-phenylene) tetracationic cyclophane (Fig. 2b) [11]. Although in these cases a large contribution to the association driving force comes from the electron-donor/acceptor (charge-transfer, CT) interactions, hydrogen bonding can also play an important role, as clearly shown in the cases of pseudorotaxanes constituted by 4, 4 -bipyridinium [12a] or l,2-bis(pyridinium)ethane [12b] threads and crown ethers. 

The efficiency of the self-assembly process is retained when BPP34C10 is replace by l,5-dinaphtho-38-crown-10 (1/5DN38C10) with its l,5-dioxyn2 hthalene 7C-donor units Scheme 13). Apparently the n htho rings are sterically acceptable, while the greater 7c-donating ability enhances the rate of reaction. The desired [2]catenane was self-assembled in 51% yield from the components, i.e., 1/5DN38C10, BBB, and [BBIPYXY][PF6]2. 

Starting from a 1 2 mixture of an electron-rich bis-l,5-(dinaphtho)-38-crown-10 and the electron-poor bis-acetylenic compound 1, Sanders used the template effect obtained by the inclusion of the pyromellitic diimide 1 in the crown ether to direct the oxidative coupling of the terminal alkynes toward the formation of the cyclized structure, the [2]catenane, with a 38% chemical yield. When 1 was replaced by a more electron-poor moiety obtained from 1,4,5,8-naphthalene tetracarboxylic diimide (2, Scheme 17.5) the yield of the catenane improved to 52%. 

A large munber of catenanes and rotaxanes bearing l,5-dinaphtho-38-crown-10, e.g. 61, as a donor have been reported. As seen in recent papers, paraquat and diquat dication maaocycles or some rod derivatives as acceptor components are often utilized [76-85]. 

Dinaphthizone, D-00931 Dinaphtho-30-crown-10, D-00932 y -Dinaphthol, see D-00544 Di-a-naphthyl diketone, see D-00930 Di(l-naphthylmethyl)amine, see B-00427 A, A -Di-(2-naphthyl)-p-phenylenediamine, see D-00929... 

---