Diethylphosphinic acid

The main gases evolved from PA6 and PA6 + NC in nitrogen are e-caprolactam, hydrocarbons, carbon dioxide, water, and ammonia. Other composites namely PA6 + FR and PA6 + FR + NC evolve the same volatiles with an additional phosphorous containing species. PA6 + FR yields diethylphosphinic acid (from aluminum diethylphosphinate), and the water and carbon dioxide arise from the decomposition of melamine polyphosphate through condensation and hydrolytic decomposition. 

PROBLEM 2.42 Write Lewis structures for ethane, ethylene, acetylene, ethanol, ethanethiol, tetraethylammonium ion, diethylphosphine, the imine of diethyl ketone, diethylborane, tetraethylborate ion, diethyl ether, diethyl sulfide, acetaldehyde, acetone, acetic acid, ethyl acetate, acetamide, acetyl chloride, propanenitrile, ethyl fluoride, and ethyl chloride. Show nonbonding electrons as dots and electrons in bonds as lines. 

Thionyl chloride added dropwise to an ice-cooled soln. of tetraethyl bi (phosphine sulfide) in benzene, then stirred 6 hrs. at rom temp. diethylphosphinic chloride. Y 78%. F. e., also thiophosphinic acid chlorides as intermediates, s. K. A. Pollart and H. J. Harwood, J. Org. Ghem. 27, 4444 (1962). 

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