A ternary complex of 1,3-xylyl-18-crown-5, tert-butylammonium perchlorate and dichloromethane

C 16H24Os.C4H12N+.C10~-.CH2C12, M r = 554.91, monoclinic, P2~, a= 11.582 (1), b= 12.396 (2), c=9.281 (1)A, fl=91.59 (1)% V= 1332.0 (5)A 3, Z=2, Dx=1.383gcm -3, #(MoKct) = 4.0 cm -l, F(000) = 588, T= 187 K, final R = 3.4% for 2154 observed reflections. The crown-tert-butyl- ammonium cation complex is of the 'nesting' type: the aryl group of the crown ether and the cation are on the same face of the crown. The -NH + group is hydrogen- bonded to three next-nearest-neighbour O atoms of the macrocycle, which has approximate D3d symmetry. On the opposite face of the ring one C1 of dichloromethane forms a close contact with the -NH~ group (C1...N + 3.554 (3)A) through the cavity of the ring and also with the intra-annular CH of the aryl group (C...C1 3.827 (4) A). Introduction. As part of a study of the complexing properties of crown ethers (Reinhoudt, de Boer, Uiterwijk & Harkema, 1985, and references therein), the complex of 1,3-xylyl-18-crown-5 with tert-butyl- ammonium perchlorate was prepared in dichloro- methane solution. Upon standing the solution at room temperature, a crystalline complex was obtained and a structure determination was undertaken.