Structures of the p-xylylenediammonium chloride and calcium hydrogensulfate adducts of the cavitand 'cucurbituril', C36H36N24O12

Structure determinations of two crystalline adducts of the cavitand cucurbituril, a cyclic hexameric dimethanoglycoluril of possible catalytic importance, are reported. Crystal data are also reported for 11 other adducts. Cucurbituril is a hexagonal cage with an internal cavity of diameter -5.5 A accessed by portals of diameter -4,~. In the p-xylylenediammonium chloride adduct of cucurbituril [C36H36N24 O 12.N H2 C H2 C6H4C H2 N H2.2 HCI. 10H20, Mr = 1386-1, F(000)= 1412, ~ =2.16cm -~, monoclinic, P2j/n, a=12.071(4), b=15.757(4), c= 14.485 (6) A, /3 =91.98 (3) °, V= 2753 (2) A 3, D,, = 1.63, Dx(Z = 2) = 1.67 gcm -3] the p-xylylenediammonium ion is a guest inside the cucurbituril cage. The structure was refined to R = 0.0624 based on 3694 independent observed reflections collected at 302 K using Mo Ka radiation. The second adduct