A high yielding (93%), regiospecific synthesis of cis(4,4')-di(carbomethoxybenzo)-30-crown-10 (1c) is reported. The derived crown ether diol 1d was converted to pyridyl cryptand 12 in 44% yield by reaction with pyridine-2,6-dicarbonyl chloride. Binding of two different 4,4'-bipyridinium (paraquat) species (3) and 2,2'-bipyridinium (diquat) 4 by 12 was explored via (1)H NMR spectroscopy, NOE experiments, mass spectrometry, X-ray crystallographic analyses, and isothermal titration calorimetry. Cryptand 12 exhibits the highest association constant for diquat ever reported (Ka = 1.9 x 10(6) M(-1)) and very high association constants for paraquats (Ka > 10(5) M(-1)) in acetone at 22 degrees C. The binding constant of diquat 4 by cryptand 12 is nearly 6-times higher than any other reported host.

The two isomers 6 and 9 of cis(4,4'-)-dicarbomethoxydibenzo-27-crown-9 with tri- and tetra-(ethyleneoxy) linkages transposed were synthesized regiospecifically in high yields (94 and 92%, respectively) by the Wang-Pederson-Wessels (WPW) protocol and were converted via the corresponding diols 7 and 10 to the corresponding pyridyl cryptands 3 and 4 by reaction with pyridine-2,6-dicarbonyl chloride. As expected from Corey-Pauling-Koltun (CPK) models, the cryptand with the tri(ethyleneoxy) arm para to the ester linkages, "short-armed" cryptand 3, did display a higher binding constant (K = 2.4 × 10 M) with paraquats than the analogous dibenzo-30-crown-10-based cryptand previously studied; however, the effect was only twofold. Its binding to diquat was reduced by an order of magnitude (1.5 × 10 M), as expected on the basis of its narrower cavity. Also as expected, the cryptand with the tetra(ethyleneoxy) arm para to the ester linkages, "long-armed" cryptand 4, possessed diminished binding with both paraquats and diquat relative to the 30-crown-based analogue; in these systems, 2:1 H:G complexes were also detected by mass spectrometry. A crystal structure is reported for 3·DQ(PF).

The pseudorotaxane complex of the new hydroxymethyl cryptand 3 with N,N'-dimethyl-4,4'-bipyridinium bis(hexafluorophosphate), PQ(PF6)2, has an association constant of 2.0(+/-0.3) x 10(4) M(-1). In the crystal structure of 3 x PQ(PF6)2 one of the bonding elements appears to be an aromatic edge-to-face interaction of a paraquat beta-proton with the hydroquinone moiety; this is the first time this interaction has been reported between a cryptand and paraquat.

Multitopic dibenzylammonium derivatives (4) of C60 were prepared by Bingel reactions of C60 with a malonate diester (2) containing two t‐BOC protected dibenzylamine moieties, followed by deprotection and protonation. Self‐assembly of model pseudorotaxanes 5 from the multidibenzylammonium C60 derivatives with dibenzo‐24‐crown‐8 was studied by 1H NMR spectroscopy and mass spectrometry. Self‐assembly of linear and star‐shaped pseudorotaxanes 8 with up to 12 arms based on polystyrenes bearing terminal DB24C8 host units (7) and the guest functionalized C60 salts was demonstrated by 1H NMR spectroscopy and solution phase viscometry. These studies provide further evidence of the potential of supramacromolecular chemistry in construction of complex polymeric architectures. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6472–6495, 2009

Two new cryptands, 2 and 4, were prepared from bis(m‐phenylene)‐32‐crown‐10 (BMP32) 5,5'‐diacid chloride and dibenzo‐30‐crown‐10 (DB30) 4,4'‐diacid chloride, respectively, by reaction with pyridine‐2,6‐dimethanol. The resultant cryptands 2 and 4 have the ester moieties reversed from the previously reported isomers, 1 and 3. These “reverse” cryptands display lower association constants with viologen derivatives than the original cryptands; this is rationalized by the conjugation of the ester moieties with the aromatic rings, which reduces their electron‐donating properties and offsets the increased basicity of the pyridyl nitrogen atoms. The crystal structure of the BMP32‐based cryptand 2 indeed confirms the coplanarity of the ester and aromatic moieties and indicates that, as a result, the available cavity is quite small and that the pyridyl nitrogen atom points away from the cavity.