Head hexyl

A great variety of chemical reactions can be advantageously carried out in microemulsions [860-862]. In one of the first papers in this field, Menger et al. described the imidazole-catalyzed hydrolysis of 4-nitrophenyl acetate in water/octane microemulsions with AOT as an anionic surfactant [=sodium bis(2-ethyl-l-hexyl)-sulfosuccinate] [864]. The solubilized water, containing the imidazole eatalyst, is confined in spherical pools encased by surfactant molecules, which have only their anionic head groups (-SOb ) immersed in the aqueous droplets. When the ester, dissolved in water-insoluble organic solvents, is added to this water/octane/AOT/imidazole system, it readily undergoes the catalysed hydrolysis under mild reaction conditions (25 °C). 

Poly(3-hexyl)thiophene with cited density of head-to-tail units. 

Micelles form when a suitable amphiphile [e.g., sodium bis(2-ethyl-hexyl)sulfosuccinate (AOT)], is introduced into a hydrocarbon solvent (e.g isooctane). Reverse micelles containing water form when water is taken up by an isooctane—AOT solution. At water contents exceeding what is needed to saturate the polar head groups forming the micelle wall, the system can properly be termed a water-in-oil microemulsion, in which water droplets stabilized by a monolayer of surfactant are dispersed in an organic solvent. For convenience, the terms reverse micelle and microemulsion are sometimes considered equivalent. There is a considerable literature on the properties of proteins, particularly enzyme activity, in reverse micelles (see Luisi and Steinmann-Hofmann, 1987, and references cited therein). 

It is of interest to compare the chemical shifts in the PMR spectra of the 2-norbomyl 5 and the 2-bicyclo[2,l,l]hexyl 143 cations. While the bridge-head protons... 

The solvolysis of tosylate obtained from bicyclo[2,l,l]hexane-2-ol-2-d, resulted in bicyclo[2,l,l]hexyl-2-acetate in which deuterium is equally distributed between the alcoholic carbon and the neighbouring bridge-head carbon which is in good agreement with the NMR spet a data. 

These materials represent the first observation of the SmC (zig-zag) and SmO (arrow head) structure in rod-coil diblock copolymers [41] in contrast to the homopolymer of poly( -hexyl isocyanate) which only form a nematic mesophase (both lyotropic [65] and thermotropic [66]). This confirms the idea by Halperin [60, 69] that rod-coil systems are a microscopic model for smectic liquid crystals in general. Although the SHIC rod-coil system has a relatively broad polydispersity, a smectic mesophase over a size scale of as much as 10 xm has been observed (Fig. 4B). This indicates that microphase separation plays a very important role in determining the self-assembly of the liquid crystalline process of these blocks. The existence of only a nematic phase in the rod homopolymer system is probably due to its broad polydispersity in contrast to the fact that a smectic meso-... 

SCHEME 7.6 Solid phase synthesis of regioregular, head-to-tail coupled, oligo 3-hexyl-thiophenes. 

---