No abstract

The thermal isomerization of a series of cyclic conjugated cis,trans,cis-trienes was examined. The results obtained show a structure-reactivity correlation between the size of the ring vs. the type of product observed. The eleven-membered-ring triene (4) yields a novel tricyclic isomer 8, whereas the nine-membered-ring triene (5) yields the bicyclic diene 9. The ten-membered analogue 3 yields a mixture of both types of observed products. Mechanistic possibilities are proposed to explain the formation of both types of products.(1) This work was supported by Grant No. AM 00709, National Institute of Arthritis, Metabolism, and Digestive Diseases.(2) (a)

No abstract

The distribution of water between gas and liquid phases was investigated for high purity HBr cylinders, and standard enthalpy of vaporization and Henry's law constant for trace amount of water in HBr were extracted. In the 3-32 {degree sign} C temperature range, the water vapor concentration in the gas phase of a cylinder is a function of cylinder temperature and the enthalpies of vaporization of water and HBr. The standard enthalpy of vaporization for trace amount of H2O in HBr was found to be 58.5 kJ/mol. The temperature dependent Henry's law constant can be expressed as: ln K(T) = -7031.44/T + 22.38. Using the thermodynamic parameters found, water vapor concentration measured for gas-phase HBr from cylinders at various temperatures can be normalized to corresponding levels at a chosen standard temperature, e.g. 21{degree sign}C. This is very important in establishing meaningful water vapor specifications, and trustworthy quality control protocols for high purity HBr gas.

No abstract