The host H, 9,9′-(ethyne-1,2-diyl)-bis(fluoren-9-ol), forms inclusion compounds with a series of alcohols with similar boiling points and displays selectivity in the sequence 3-pentanol > 2-pentanol > 3-methyl-2-butanol > 1-butanol. The structures of two polymorphic apohosts and the inclusion compounds formed with each alcohol have been elucidated. The thermal stability results agree with the selectivity results from competition experiments.