Host assemblies

The discovery that members of the resorcin[4]arene family self-assemble to form 1, owing to its classification as an Archimedean solid, prompted us to examine the topologies of related spherical hosts with a view to understanding their structures on the basis of symmetry. In addition to providing grounds for classification, we anticipated that such an approach would allow us to identify similarities at the structural level, which, at the chemical level, may not seem obvious and may be used to design large, spherical host assemblies similar to 1. 

Recently, we have been investigating the chemistry of a series of racemic diquinoline compounds that form lattice inclusion hosts. The solid-state structures of these involve only rather weak intermolecular attractions. A number of these hosts assemble by means of centrosymmetric supramolecular synthons, and therefore their enantiomer separation is limited in the solid state. 

Adamantane (47), however, only offers weak van der Waals interactions to the inner concave surface of the host assembly. This interaction, together with the enthalpic gains provided by the formation of 16 hydrogen bonds, is enough to overcome the entropy penalty for bringing together four monomers and one guest. 

Fox OD, Cookson J, Wilkinson EJS, Drew MGB, MacLean EJ, Teat SJ, Beer PD (2006) Nanosized polymetallic resorcinarene-based host assemblies that strongly bind fullerenes. J Am Chem Soc 128 6990... 

Based on the above study, larger pseudo-spherical host assemblies have been constructed from extended tetra-urea derivatives structures 29 and are... 

Foldamer duplex receptors that assemble through multimodal interactions have been developed in order to generate supramolecular host assemblies for... 

Stability Constants Definition and Determination, p. 1360 Viruses as Host Assemblies, p. 1563... 

In Fig. 1, a cyclic process for inclusion polymerization is shown. The process consists of four steps 1) hybridization of a host assembly with a solvent 2) complexation of the host with a guest monomer 3) polymerization of the monomer and 4) separation of the resulting polymer from the host. This cycle is based on spontaneous and non-covalent phenomena, such as intermolecular association and dissociation among host-host, host-guest, and guest-guest components. 

The host components (Fig. la) are first reciystallized from usual solvents for isolation and purification. This operation produces host assemblies with or without the solvents (Fig. Ib). There are two methods for obtaining inclusion compounds with the monomers (Fig. Ic) by the addition of monomers into the solvents and by replacement of the guests with retention of the host assemblies, called intercalation. 

Self-Assembling Catenanes. p. 1240 Self-Assembly in Biochemistry-, p. 1257 Self-Assembly Terminology, p. 1263 Strict Self-Assembly and Self-Assembly with Covalent Modifications, p. 1372 The Template Effect, p. 1493 Viruses as Host Assemblies, p. 1563... 

The simultaneous binding of cations and neutral molecules can be achieved by different types of molecular hosts or assemblies. Traditional host molecules such as crown ethers and calixarenes can complex both a cation and neutral molecule within different receptor sites. Metallohosts, where a metal cation is an intrinsic part of the host assembly, can complex neutral molecules within... 

Dynamic structure conversion can often be affected by the addition of a guest molecule that drives the system to form a new host assembly. Tetragonal, pentagonal, and hexagonal circular helicate structures with Fe have been produced from very similar or identical ligands. ... 

Figure 27 Multicomponent crystals designed to stabilize reactive chemical species, (a) Generic chemical structures of each component of benzyl(hexadecyl)dimethylammonium chloride sesquikis(hydroquinone), (b) supramolecular chains comprising hydroquinone and chloride anions, and (c) view of the incorporation of the supramolecular chains shown in (b) within the host assembly comprising the ammonium cations. The 0-H- O and O-H- Cl hydrogen bonds are shown as orange and blue dashed Unes, respectively.

Rodell, C.B., Kaminski, A.L., Burdick, J.A., 2013. Rational design of network properties in guest-host assembled and shear-thinning hyaluronic acid hydrogels. Biomacromolecules... 

J. L. Atwood, L J. Barbour and A. Jerga, Calixarene-based guest-host assemblies for guest storage and transfer, (USA). 2004, 2002-286179, 2004087666... 

Mullen KM, Mercurio J, Serpell CJ, Beer PD (2009) Exploiting the 1,2,3-triazolium motif in anion-templated formation of a bromide-selective rotaxane host assembly. Angew Chem Int Ed 48 4781... 

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