Benzo-cis-cyclohexano-14-crown-4 and its lithium thiocyanate complex
The structures of a 14-crown-4 ether containing both benzo and cyclohexano substituents, 2,6,13,17-tetraoxatricyclo-[16.4.0.0(7, 12)]docosa-1(18),19,21-triene, C(18)H(26)O(4), and its lithium complex, [2,6,13,17-tetraoxatricyclo[16.4.0.0(7,12)]docosa-1(18),19, 21-triene-kappa(4)O](thiocyanato-N)lithium(I), [Li(NCS)-(C(18)H(26)O(4))], are presented. The conformation of the free crown, (I), is not preorganized for cation binding, as its donor dipoles are oriented towards opposite sides of the crown ring. The Li(+)-crown complex, (II), exhibits two formula units in the asymmetric unit. The binding conformation observed in (II) does not completely reorient the dipoles to one point, resulting in a long Li-O bond length [2.068 (5) and 2.073 (5) A].
Bryan
JC
Chemical and Analytical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6119, USA. bryanjc@ornl.gov.
Sachleben
RA