The mono- and bis-tetrabutylammonium salts of 2-ethyl-spirobifluorene monophosphonate and (+/-) 2,2'-diethyl-7,7'-didodecyloxy-spirobifluorene diphosphonate respectively, were synthesized and shown to bind strongly to a series of 1-O-octylglycosides in CD3CN. (C) 1997 Elsevier Science Ltd.