Abstract: This invention relates to new products comprising at least one isomer of polyfluorinated-chain phosphine oxide with the general formula (I):c.sub.n F.sub.2n+1 (C.sub.2 H.sub.4) PO (CH.sub.3).sub.2 (I)and complying with one of the developed formulae II or III : ##STR1## in which C.sub.n F.sub.2n+1 represents a perfluorinated aliphatic chain, n lying between 2 and 18.The invention further relates to methods of obtaining the phosphine oxides of formula I.

Abstract: Phosphoric esters of polyfluorinated alcohols are disclosed comprising at least one isomer of phosphorous esters of polyfluorinated alcohols, or one of the derivatives thereof, said esters and derivatives thereof corresponding to the general formula: ##STR1## said two isomers corresponding to formulae (II) and (III): ##STR2## wherein C.sub.n F.sub.2n.sub.+1 is a perfluorinated aliphatic chain, n is an integer from 2 to 18, X and Y are the same or different and are each a halogen atom, a hydroxy radical, the group OM in which M is a metallic equivalent, or an alkoxy, chloroalkoxy, hydroxypolyalkylenoxy, aryloxy, or --NZZ' group in which Z and Z' are the same or different and are each a hydrogen atom or an alkyl, cycloalkyl or aryl group.The preparation of phosphoric esters having the general formula (I) and mixtures of the isomers (II) and (III) thereof are also disclosed.

Abstract: New monoesters of phosphoric acid with polyfluorinated glycols having the formulasC.sub.n F.sub.2n.sub.+1 CHYCH.sub.2 --OP(O)(OH).sub.2 ##STR1## wherein Y is hydroxyl, can be prepared by alkaline saponification of the corresponding compounds wherein Y is chlorine. The new diacid monoesters and their salts are effective surfactants, unexpectedly stable in alkaline media.