Chemical Reviews, 1999, Vol. 99, No. 7 7A
In Color on the Front Cover (Top) Space-filling representation of the X-ray crystal structure of a branched [7]catenane, composed of a central cyclobis(paraquat-4,4′-biphenylene) cyclophane (black) interlocking two tris-1,5-naphtho-57-crown-10 macrocycles (yellow and green) which are also each encircled by pairs of cyclobis(paraquat-p-phenylene) cyclophanes that are blue and orange and red and black. (Courtesy of Prof. D. J. Williams, Imperial College, London.) See “Interlocked Macromolecules” by Franc¸ isco M. Raymo and J. Fraser Stoddart, p 1643. (Lower left) Formation of a DNA-linked nanoparticle network through programmed recognition. The different colors represent particles of differing composition. See “Programmed Materials Synthesis with DNA” by James J. Storhoff and Chad A. Mirkin, p 1849. (Lower right) Simultaneously acquired topographic (upper) and photon intensity (lower) maps (180 Å × 180 Å) of a gold nanoparticle showing localized photon emission. See “Scanning Probe Studies of Single Nanostructures” by Gregory S. McCarty and Paul S. Weiss, p 1983. In Color on the Back Cover (Top left) Ligating sites on branched scaffolding allow metal incorporation on the dendrimer surface but also within the interior to facilitate branching, monomer connectivity, structural changes, and macromolecular juxtapositioning. See “Suprasupermolecules with Novel Properties: Metallodendrimers” by George R. Newkome, Enfei He, and Charles N. Moorefield, p 1689. (Second left) SEM micrograph of single-walled carbon nanotube bundles. Inset: schematic expected close-up view of a bundle made of several nanotubes, each with a hexagonal lattice of carbon atoms. See “Nanotubes from Carbon” by P. M. Ajayan, p 1787. (Lower left) Light micrograph of the scales of two different butterfly wings, Ornithoptera priamus with green scales and Necyria duellona with blue scales. See “Nano-Optics in the Biological World: Beetles, Butterflies, Birds, and Moths” by Mohan Srinivasarao, p 1935. (Top right) Space-filling model of fifth-generation poly(propylene imine) dendrimer functionalized with N-t-BOC-L-Phe groups on the periphery. The N-t-BOC-L-Phe end groups are red and the core atoms green, white, and blue. See “About Dendrimers: Structure, Physical Properties, and Applications” by A. W. Bosman, H. M. Janssen, and E. W. Meijer, p 1665. (Third right) Transition from the solid crystalline phase into the discotic columnar mesophase as found with many polyaromatic hydrocarbons, and a 3-D representation of a dendritic polyphenylene. See “Polyphenylene Nanostructures” by Alexander J. Berresheim, Markus Mu¨ller, and Klaus Mu¨llen, p 1747.
