Hydrogen-Bonding Assembly

When arborol 21 is added in low concentrations to an aqueous environment gelation occurs. The propensity of minimize lipophilic-hydrophilic interactions as well as maximize //-bonding and packing effects is proposed as the reason for the formation of the 

Incorporation of an alkyne moiety within the lipophilic core (e.g., 23) imparts helical and scissors-like morphology to the stacked array (e.g., 24 and 25, respectively). Disclike, benzene-based arborols have also been reported1891 to form //-bonded aggregates, or networks, comprised of approximately 50-60 dendrimers. The approximation is based on network diameters determined from electron microscopy. 

20 A thick (molecular weight ca. 34,000 amu) are formed via a dual, non-covalent mode of construction comprised of complimentary topological and //-bonding aspects. 

Stoddart et al.l ,lb have reported the self-assembly of branched [njrotaxanes in an investigation aimed at the preparation of larger, dendritic rotaxanes. Kato et al. 9lcl have reported the preparation of supramolecular liquid crystalline networks based on self-assembly of carboxylic acid-based, trigonally branched, //-bonding donors and bipyridine-type //-bonding acceptors. 

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Ajayaghosh A, George SJ, Schenning APHJ (2005) Hydrogen-Bonded Assemblies of Dyes and Extended jr-Conjugated Systems. 258 83-118 Akai S, Kita Y (2007) Recent Advances in Pummerer Reactions. 274-. 35-76 Albert M, Fensterbank L, l.acote E, Malacria M (2006) Tandem Radical Reactions. 264 1-62 Alberto R (2005) New Organometallic Technetium Complexes for Radiopharmaceutical Imaging. 252 1-44... 

Kay ER, Leigh DA (2005) Hydrogen Bond-Assembled Synthetic Molecular Motors and Machines. 262 133-177... 

V. A. Russell, M. D. Ward, Two-dimensional hydrogen-bonded assemblies the influence of sterics and competitive hydrogen bonding on the structures of guanidinium arenesulfonate networks , J. Mater. Chem 1997, 71123-1133. 

Ajayaghosh A, George SJ, Schenning APHJ (2005) Hydrogen-Bonded Assemblies of Dyes and Extended jr-Conjugated Systems. 258 83-118 Alberto R (2005) New Organometallic Technetium Complexes for Radiopharmaceutical Imaging. 252 1-44... 

The rhombic (4,4) networks differ in the supramolecular interactions linking the cations and anions. For eleven (Table 2), alternating cations and anions are linked directly through hydrogen-bonded interactions. For two (Table 2) the supramolecular hydrogen-bonding assemblies incorporate protic solvents and for a single example (Table 2) there are no molecular interactions. 

When the hydrogen-bonding assemblies incorporate water [Cu(LHe)2] Cl2-H20 or methanol [Cu(Lmm)2]Br2-MeOH molecules to maintain (4,4) grid formation (Scheme 9) the 2-D sheet adopts a severely corrugated profile (<(>=73.6° and 90°, respectively), Similarly, when a molecular structure is formed [Cu(Lbm)2] Cl2, the corrugated profile has a very large amplitude (< >=130.6°). 

Cai, M. Shi, X. Sidorov, V. Fabris, D. Lam, Y.-F. Davis, J. T. Cation-directed self-assembly of lipophilic nucleosides The cation s central role in the structure and dynamics of a hydrogen-bonded assembly. Tetrahedron 2002, 58, 661-671. 

GENERAL CONSIDERATIONS FOR THE DESIGN OF ELECTROCHEMICALLY CONTROLLED HYDROGEN-BONDED ASSEMBLIES... 

Prins, L. J., Huskens, J., de Jong, F., Timmerman, P., Reinhoudt, D. N., Complete asymmetric induction of supramolecular chirality in a hydrogen-bonded assembly. Nature 1999, 398, 498-502. 

Derossi, S., Adams, H., Ward, M. D., Hydrogen-bonded assemblies of ruthenium(II)-biimidazole complex cations and cyanometallate anions structures and photophysics. Dalton Trans. 2007, 33-36. 

Kay, E. R. and Leigh, D. A., Hydrogen bond-assembled synthetic molecular motors and machines , Top. Curr. Chem. 2005, 262,133-177. 

Papaefstathiou, G. S. MacGillivray, L. R. Discrete Versus Infinite Molecular Self-Assembly Control in Crystalline Hydrogen-Bonded Assemblies based on Resorcinol. Org. Lett. 2001, 3, 3835-3838. 

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