Complexation with diol host compounds. Part 32.† Separation of lutidine isomers by 1,1,6,6-tetraphenylhexa-2,4-diyne-1,6-diol

The title host compound forms inclusion compounds with 2,4-, 3,5- and 2,6-lutidine. In each case the host∶guest ratio is 1∶2 and the structures are stabilised by (Host)O–H· · ·N(Guest) hydrogen bonds. Competition experiments show that the host selects the guests in order of preference of 3,5-lutidine > 2,6-lutidine > 2,4-lutidine. These results are in general agreement with the lattice energy calculations.