... is c. 81% pure. Mol. wt. 449.9 M.f. C23H19ClF3NO3 Form Colourless solid; (tech. is a dark ... brown/green solidified melt). M.p. 49.2 ; (tech., 47.5-48.5 ) B.p. Does not boil at ... 15-25 . pKa >9 (hydrolysis prevents measurement) F.p. 185 (tech., Pensky-Martens closed cup) COMMERCIALISATION History Insecticide ... and soya bean leaves, see D. A. French & J. P. Leahey, Proc. Br. Crop Prot. Conf. - Pests Dis., ...