Molecular hexagons

Ali, M.M. and MacDonnell, F.M. (2000) Topospecific self assembly of mixed-metal molecular hexagons with diameters of 5.5 nm using chiral control. J. Am. Chem. Soc., 122 (46), 11527-11528. 

Figure 5.22 Cu UPD on a Au/mica substrate network are filled with adamantane thiol modified by a hybrid nanostructure consisting of (circles), (b) STM images of network-SAM a hydrogen-bonded network and a thiol SAM. hybrid structure with inset showing the (a) Cartoon ofthe hybrid structure and molecular hexagonal thiol island at molecular resolution, structures of the components. The hydrogen- (c, d) Schematic illustrations and STM images of...

Ketones in 120° sp configuration can give molecular hexagons (Scheme 48). Less symmetric molecular rectangles can be achieved by the reaction of a designed diplatinum clip and linear bridging ligands (Scheme 49). Similar... 

Since the development of grazing incidence x-ray diffraction, much of the convincing evidence for long-range positional order in layers has come from this technique. Structural relaxations from distorted hexagonal structure toward a relaxed array have been seen in heneicosanol [215]. Rice and co-workers combine grazing incidence x-ray diffraction with molecular dynamics simulations to understand several ordering transitions [178,215-219]. 

Good semi-quantitative agreements are found in diffraction patterns and proposed models obtained by molecular-dynamics[14], because the results of the ex-periments[31-34] are consistent with the atomic models proposed by us[14]. However, in the present state of high-resolution electron microscopy, taking into account, moreover, the number of sheets and the complicated geometry of the helix, it seems unlikely to directly visualize the pentagon-hexagon pairs. 

Whenever the polymer crystal assumes a loosely packed hexagonal structure at high pressure, the ECC structure is found to be realized. Hikosaka [165] then proposed the sliding diffusion of a polymer chain as dominant transport process. Molecular dynamics simulations will be helpful for the understanding of this shding diffusion. Folding phenomena of chains are also studied intensively by Monte Carlo methods and generalizations [166,167]. 

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