Enthalpimetry of non-aromatic alkenes.
A method of increased sensitivity for hydrogen enthalpimetry of olefins in mumole quantities is reported. The method depends on a linear relationship between the amount of alkene present and the heat given off on hydrogenation at slightly more than 2 atm pressure over palladium catalyst on charcoal. Least-squares analysis of the results shows that the measured heat effect is a linear function of amount of alkene taken, with a relative standard deviation of 1-3% for samples ranging in size from 1.4 to 37.5 mumole. Extension of the method to samples in submicromolar quantities was only partially successful; in a series of measurements extending to a minimum amount of 0.64 mumole, the relative standard deviation rose to 9.6%.
Rogers
D W
DW
Chemistry Department The Brooklyn Center Long Island University Brooklyn, New York 11201, U.S.A.
Sasiela
R J
RJ