Multidimensional Kramers rate theory is employed to examine the influence exerted by double bonds on the kinetics of conformational transitions of single bonds in trans-polybutadiene and poly(transpropenylene). For both molecules, a detailed discussion of the geometric and potential energy factors that determine the transition rates of the various types of single bonds is presented. Single bond...

We report a new surface-initiated polymerization strategy that yields superhydrophobic polymethylene (PM) films from initially smooth substrates of gold and silicon. The films are prepared by assembling a vinyl-terminated self-assembled monolayer, followed by exposure of the surface to a 0.1 M solution of borane, and polymerizing from the borane sites upon exposure to a solution of diazomethane...

Three homologous series of polymethylene-a,i<;-bis[2-thio-5(4’,4'’n-alkoxybenzoyloxy)phenyl]-l,3,4-oxadiazole (series 5 a, b, c), are reported.The compounds have identical mesogenic units at both ends of a spacer (i.e. they are twins). These twins possess a spacer of 6, 8 and 10 carbon atoms joined directly to the oxadiazole ring through sulphur atoms. The lateral alkylic chains vary between 6 ...

BACKGROUND Of the polymethylene bismethonium congeners (C5-C12 and C18), decamethonium (C10) is the most potent neuromuscular blocking agent. We tested the hypothesis that these congeners act as straight molecules and will not bend easily in spite of the flexible connecting chain between the methonium heads. For congeners higher than C10, we also hypothesized that the relative difficulty with w...

The first total synthesis of leopolic acid A, a fungal metabolite with a rare 2,3-pyrrolidinedione nucleus linked to an ureido dipeptide, was designed and carried out. Crucial steps for the strategy include a Dieckmann cyclization to obtain the 2,3-pyrrolidinedione ring and a Wittig olefination to install the polymethylene chain. An oxazolidinone-containing leopolic acid A analogue was also syn...

[structure: see text] An efficient, enantioselective synthesis of the C1-C12 fragment 2 of borrelidin is presented. Construction of the "skipped" polymethylene chain of 2 was accomplished by iteration of Myers' alkylation, while formation of the C3 stereocenter was achieved by Roush's asymmetric allylboration methodology.

We report herein the syntheses of several analogues of stearic acid in which oxygen or sulfur atoms or sulfoxide groups have replaced the methylene groups at either position 9 or position 10 of the polymethylene chains. These compounds have been fully characterized by the results of proton and carbon 13 nuclear magnetic resonance, and low and high resolution mass spectral studies.