Hydrogen bonding supramolecular complexes

Eblinger, F. Schneider, H.-J. Stabilities of hydrogen-bonded supramolecular complexes with various numbers... 

Figure 6 Double hydrogen-bonded supramolecular complex 7.

Eblinger, F. Schneider, H. J. (1998) Stabilities of hydrogen-bonded supramolecular complexes with various numbers of single bonds Attempts to quantify a dogma in host-guest chemistry, Angew. Chemie-Intl Edn, 37, 826-829. 

Figure J. 1. Some supramolecular architectures of hydrogen bonded Whitesides complexes.

Nucleobases and nucleosides are common motifs for hydrogen-bonded supramolecular arrays. Ng et al. first reported a series of phthalocyanine-nucleobase conjugates [64], The tetra-adenine phthalocyanine 64 was prepared by standard <9-alkylation of zinc(II) tetrahydroxyphthalocyanine with 9-(2-bromoethyl)adenine in the presence of K2CO3. The fluorescence of 64 is quenched substantially upon addition of thymine-substituted 9,10-anthraquinone 65, and the rate is much faster compared with that for the situation when the unsubstituted 9,10-anthraquinone is used as the quencher. These results suggest that 64 forms a supramolecular complex with 65 through the Watson-Crick base-pairing interactions. 

The uptake of C6o corresponds to the increase in absorbance at 258 and 328 nm in the absorption spectrum of 1 + C6o (Fig. 23). Comparison of a solution of 1 + C6o with a saturated solution of C60 in chloroform showed that the Cgo concentration increased 16-fold in the presence of NDI nanotubes (1). In contrast with these results, the methyl ester of 1, which is unable to form hydrogen-bonded supramolecular nanotubes, did not enhance the solubility of C60 in chloroform, supporting the thesis that the Cfi0 molecules are complexed in the inner nanotubular cavity. The increase in absorbance at 258 nm also led to an estimate of [NDI]/[C6o] stoichiometry, revealing that an average of 3.6 NDI units were encapsulating one Cfi0 molecule. Similar results were also obtained with other amino acid derivatives of NDI. 

Doubly hydrogen-bonded supramolecular polymers 35 and 36 consisting of carboxylic acid and diaminopyridine moieties exhibit monotropic liquid-crystalline behavior [63a, 83]. A texture of dendritic growth characteristic of columnar phases is seen for the complex [63a]. 

Keywords Anion recognition Complexation Crystal structures Hydrogen bonding Supramolecular chemistry... 

Most hydrogen bonded rodlike supramolecular LCs often show smectic or nematic phases because of their rodlike shape. Hydrogen bonded rodlike complexes 1, 6, 7, 8 are nematic mesogens. Mesogenic complex 6 composing with only two... 

Masci, B. Gabrielli. M. Mortera. S.E. Nierlich. M. Thuery, P. Hydrogen bonded supramolecular assemblies from uranyl ion complexes of tetrahomodioxacalix[4]ar-enes with various counterions. Polyhedron 2002, 21 (11). 1125-1131. 

Figure28 (a) Hydrogen-bonded polymeric complex 38 and (b) supramolecular random copolymer 39.

Doubly hydrogen-bonded supramolecular mesogenic complexes have been derived by the formation of the hydrogen bonds between 2-aminopyridyl and carboxylic acid moieties [43,44]. Complex 24 sharply melts... 

Figure 3.5 Attachment of complex hydrogen-bonding systems to bis-telechelic PIB prepared by LCCR (Reprinted with permission from W.H. Binder, MJ. Kunz, C. Kluger et aL, Synthesis and analysis of telechelic polyisobutylenes for hydrogen-bonded supramolecular pseudo-block copolymers, Macromolecules, 37, 5, 1749-1759, 2004. 2004 American Chemical Society.)...

In addition to the homodimeric units described above, which form by self-complementary hydrogen bonding, heterodimeric complexes may also be effective for supramolecular polymer construction. Three such complexes are 1 2, r 9, and 10 11(9). Complex 7 9 = 3500 (NT, 5% DMSO-t/g/CDClj)... 

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