3,7-bis(2-hydroxyethyl)-5-[(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-nonadecafluoroundecyl)oxy]-4,6-dioxa-3,7-diaza-5-phosphanonane-1,9-diol 5-oxide