Wendell L. Dilling

Development and tribological properties of new cyclotriphosphazene high temperature lubricants for aircraft gas turbine engines

A number of substituted aryloxycyclotriphosphazenes were synthesized and studied, with the objective of meeting the lubricant requirements of the Integrated High Performance Turbine Engine Technology (IHPTET) initiative. These compounds were evaluated for pour point, oxidative stability, and lubricity behavior. Further property evaluations were performed on a leading candidate fluid, bis(4-fluorophenoxy)-tetrakis(3-trifluoromethylphenoxy) cyclotriphosphazene, code-named X-1P. The results of this study are discussed, along with comparative data of other leading commercial high temperature fluids. Presented at the 46th Annual Meeting in Montreal, Quebec, Canada April 29–May 2, 1991

Organic photochemistry. 20. A method for estimating gas-phase rate constants for reactions of hydroxyl radicals with organic compounds from their relative rates of reaction with hydrogen peroxide under photolysis in 1,1,2-trichlorotrifluoroethane solution

The reaction with hydroxyl radicals appears to be the major transformation route for many organic compounds in the atmosphere. To avoid the difficulties of measuring the rate constants for these reactions in the gas phase for some compounds, we have developed a solution-phase system for measuring relative rates. This system involves photolysis of continuously extracted 90% hydrogen peroxide into 1,1,2-trichlorotrifluoroethane solution, which contains two or more organic compounds, one of which serves as a reference standard whose gas-phase rate constant is known. Reasonable correlations (r/sup 2/ = 0.84, 0.87) were obtained between the relative solution-phase rates and the absolute gas-phase rate constants, which varied over 4 orders of magnitude for n-hexane, 2,2,4-trimethylpentane, cyclohexane, 1,1,1,-trichloroethane, cyclohexene, trichloroethene, tetra-chloroethene, ethyl acetate, toluene, n-propylbenzene, o-xylene, p-isopropyltoluene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, biphenyl, naphthalene, hexafluorobenzene, o-dichlorobenzene, m-dichlorobenzene, 1,2,4-trichlorobenzene, anisole, and nitrobenzene. This method allows estimations of the gas-phase rate constants to within 1 order of magnitude or better.

An infrared study of the tautomerism of chlorinated 2-pyridinols isolated in an argon matrix

Abstract The infrared spectra of 3-, 4-, 5- and 6-monochloro-, 3,5,6-trichloro-2-pyridinols (pyridones), and of the unsubstituted 2-pyridinol isolated in a low temperature (20°K) argon matrix were studied. The results indicate that the enol/keto ratio for the isolated pyridinols decreases according to the position of the chlorine atom(s) on the pyridine ring; i.e., 3,5,6-trichloro >-6 > 5 > 4 > 3 monochloro-2-pyridinols. 3,5,6-Trichloro-2-pyridinol exists predominantly in the enol form.

Pentacyclodecane chemistry—III: Fragmentation patterns of pentacyclodecane derivatives on electron impact

Abstract The fragmentation patterns on electron impact of 10 derivatives of pentacyclo-[5.3.0.02,6.03,9.04,8] decane and 5 derivatives of pentacyclo[5.3.0.0.2,6.03,9.05,8]decane were investigated. The predominant mode of fragmentation was cleavage of the pentacyclodecane nuclei in half except for the ketone derivatives. Other major fragmentation routes are discussed.

ORGANIC PHOTOCHEMISTRY—XV. APPLICATIONS OF PHOTOCYCLOADDITION REACTIONS IN NATURAL PRODUCT SYNTHESES*,†

Abstract— Photocycloaddition reactions which have been employed as one of the steps in the total/ synthesis of natural products are reviewed. The utility of the cycloadducts in these syntheses is also discussed.