Templated structures layered

In a different reaction scheme, one can take advantage of the fimctional porphyrin macrocycle to create metalloporphyrin compounds and nanoarchitectures in 2D. Upon exposure of regular TPyP arrays self-assembled on Ag(lll) to iron monomers supplied by an atomic beam, selective com-plexation occurs whereby the template structure is strictly preserved [156]. This expands the diversity of metalloporphyrin layers conventionally realized by evaporation of integral species, because in-situ metalation provides a route towards novel metalloporphyrin nano architectures and patterned surfaces [156-158]. In a related reaction pathway, evidence could be obtained for in-situ complexation and metal center-induced switching of phenanthroline-based catenane units deposited the Ag(lll) surface [182]. 

Electrochemical deposition of metals in the pores of templating membranes requires that one side of the membrane be in direct contact with a metallic layer. This can be produced by plasma or vacuum deposition of a metal layer on one side of the membrane (25) and requires that the membrane film be robust enough to tolerate this kind of manipulation. The thickness of the conductive layer is typically 100-1000 nm (45-47). The metal which produces the conductive layer can be the same or different from the one that will provide the final template structure. In electrochanical template deposition, the coated film is placed in an electrochemical ceU where the template membrane acts as the cathode and a counter electrode is the anode. The deposition can be carried out under galvanostatic or... 

Strong polyelectrolyte complexes are generally insoluble in conventional polar organic solvents or water, except at the extremes of pH. Ternary component systems comprising water, polar organic solvents and salt have been employed for solubihzation [927]. Polyelectrolyte complexes can form many structures, of which ladder-type, chaotic scrambled-egg -type, crystalhne complexes formed by template polymerization, layer-by layer structures, core-shell structures and hehcal conformations have been noted. 

Thus zeolite ZSM-5 can be grown (ref. 15) onto a stainless steel metal gauze as shown in Figure 6. Presumably the zeolite crystals are chemically bonded to the (chromium-) oxide surface layer of the gauze. After template removal by calcination and ion exchange with Cu(II) a structured catalyst is obtained with excellent performance (ref. 15) in DeNOx reactions using ammonia as the reductant. 

Electrochemical template-controlled sjmthesis of metallic nanoparticles consists of two steps (i) preparation of template and (ii) electrochemical reduction of metals. The template is prepared as a nano structured insulating mono-layer with homogeneously distributed planar molecules. This is a crucial step in the whole technology. The insulating monolayer has to possess perfect insulating properties while the template has to provide electron transfer between electrode and solution. Probably, the mixed nano-structured monolayer consisting of alkylthiol with cavities which are stabilized by the spreader-bar approach [19] is the only known system which meets these requirements. 

The presence of triethylenetetramine in the hydrothermal synthesis of open-framework zinc phosphates results in a number of frameworks with one- to three-dimensional structures. The structures include one-dimensional ladders, two-dimensional layer structures, and one structure where the tetramine is bound to the zinc center. The structural type was highly sensitive to the relative concentration of the amine and phosphoric acid.411 Piperazine and 2-methylpiperazine can be used as templating molecules in solvothermal syntheses of zinc phosphates. The crystallization processes of the zinc compounds were investigated by real time in situ measurements of synchrotron X-ray powder diffraction patterns.412... 

The pores of the silica template can be filled by carbon from a gas or a liquid phase. One may consider an insertion of pyrolytic carbon from the thermal decomposition of propylene or by an aqueous solution of sucrose, which after elimination of water requires a carbonization step at 900°C. The carbon infiltration is followed by the dissolution of silica by HF. The main attribute of template carbons is their well sized pores defined by the wall thickness of the silica matrix. Application of such highly ordered materials allows an exact screening of pores adapted for efficient charging of the electrical double layer. The electrochemical performance of capacitor electrodes prepared from the various template carbons have been determined and are tentatively correlated with their structural and microtextural characteristics. 

---