Solids, supramolecular synthesis self-assembly

Indeed, we anticipate that the Platonic and Archimedean solids may be used for the construction of hosts which conform to those solids not yet realized and additional members of each family, where supramolecular synthesis, via self-assembly, will play a major role in their design, ushering in an era of spherical host-guest chemistry. 

The Fc-modified uridine was incorporated into DNA trinucleotides with standard solid-phase synthesis. An interesting Fc conjugate has also been reported recently having an Fc group linked to two nucleobases such as thymine/uracil. These conjugates form supramolecular assemblies by base paring directed self-assembly.92... 

Desiraju has reported a crystalline supramolecular wheel-and-axle compound with a structure based on a carboxylic acid dimer.33 Specifically, the group predicted that 4-(triphenylmethyl)benzoic acid would self-assemble to give a homodimer. The dimer was expected, owing to an inability to efficiently pack, to form inclusion compounds that host solvent molecules as guests. Such inclusion would be reminiscent of structurally similar organic molecules that serve as wheel-and-axle compounds in the solid state. The homodimer would, thus, circumvent a covalent synthesis. As predicted, the carboxylic acid formed a homodimer that produced solids that exhibited solvent inclusion (Fig. 15). The packing was dominated by... 

A solvent-free self-assembly offullerene Cjq using high-speed vibration milling has been described [19]. This simple, efficient, and green pathway to the synthesis of a supramolecular complex in the solid state opened a new avenue for the application of solventless reactions. 

In this extensive study of thiourea synthesis by coupling isothiocyanates with amines under mechanochemical conditions of neat and LAG, a total of 49 different thiourea derivatives were prepared. Since the supramolecular chemistry of simple synunetrical and nonsymmetrical diarylthiouieas had not previously been studied in detail, the information from the PXRD patterns of the milling products in this work also allowed for a systematic analysis of structural features of diarylthio-ureas. The three main self-assembly motifs were identified. A characteristic supramolecular synthon based on bifurcated N—H - S hydrogen bonds was found in most cases, whereby the individual thiourea molecules were assembled into chains aligned in a head-to-head (parallel molecular dipoles) or head-to-tail (antiparallel molecular dipoles) manner. In the case of slerically hindered thioureas, such as A -(2,6-dimethylphenyl)-A -phenylthiourea, the third motif arising from discrete cen-trosymmetric dimers based on rI(S) supramolecular synthon was found. A detailed look at the measured PXRD patterns for aU diarylthioureas revealed that solid-state structures of these compounds could be classified into two structural families, denoted as family I and family II (Fig. 1.11). 

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