Photoderivatization of the Surface of Luminescent Porous Silicon with Formic Acid

Assembly of Hexamolybdenum Metallic Clusters on Silicon Surfaces

“…[26] As the chemistry of porous silicon is similar to that of flat silicon crystals, this technique is very powerful for the identification of surface species. [27] The FTIR spectrum of hydrogenterminated porous SiA C H T U N G T R E N N U N G (100) consists solely of nSi-H x stretching modes at 2087 cm À1 for nSi-H, 2115 cm À1 for nSi-H 2 and 2140 cm À1 as a shoulder for nSi-H 3 ( Figure 3). After derivatization with undecylenic acid, the spectrum shows peaks due to the stretching and deformation of the CH 2 groups of the alkyl linker at 2925 and 2854 cm…”

Photopatterned Hydrosilylation on Porous Silicon

“…A very useful regiospecific application of the light-promoted hydrosilylation reaction involves alkyl substitution of the por-Si surface through photopatterning. [15] A white light pattern is focused on a por-Si sample to which neat liquid alkene or alkyne has been applied. After reaction times of 15 min or longer, alkyl incorporation in the illuminated areas can clearly be identified under PL conditions.…”

“…[11±13] We recently studied hydrogen bond directed self-assembly of chiral fibers [14] and microtubes [10,15,16] from synthetic sugar-and peptidebased bolaamphiphiles. [17] In light of the wide applicability of AFM, we explored vertical profiles along the molecular long axes within the microtube [15] made up of glycylglycine bolaamphiphile 1.…”

“…[17] In light of the wide applicability of AFM, we explored vertical profiles along the molecular long axes within the microtube [15] made up of glycylglycine bolaamphiphile 1. Here we report a molecularly resolved layered structure within the tube membranes that was observed by contact AFM in air.…”

“…Spherical, brighter portions (denoted by arrows in Figure 1 a) correspond to topographically higher regions, and indicate the encapsulation of vesicular assemblies in the compartment. [15] Cross-section analysis of the portions with and without vesicle encapsulation provided information on the thickness of the tube membranes; the value of less than 100 nm corresponds to less than 30 ± 40 molecular layers. [10] In addition, a high-resolution AFM image of the tube surfaces also revealed a distorted hexagonal arrangement of the peptide head groups.…”