| Abstract
| - The preorganized, macrobicyclic azaphane (1) exhibits remarkable strong, selective fluoridebinding comparable to the most effective bis(tren) cryptands despite binding anions via only three NHgroups coupled with three CH hydrogen bond donors. The lower intrinsic affinity of CH donors iscompensated by the high degree of preorganization exhibited by azacyclophane 1. Compound 1 is preparedvia a tripod−tripod cyclization reaction between 1,3,5-tris-bromomethyl-benzene and an aliphatic tripodalhexatosylated polyamine, followed by the reduction of the resulting bicyclic tosylamine. The crystal structuresof the bicyclic tosylamine 2 and four macrobicyclic polyammonium halide salts of 1 are reported. X-raystudies revealed the formation of inclusive 1:1 complexes of 1 with fluoride, chloride, bromide, and iodide.Potentiometric titrations showed very high binding constants for fluoride and chloride with a F-/Cl- selectivityof more than five logarithmic units. The final geometry of the anion cryptates is largely determined byoptimization of NH and CH···anion interactions coupled with unfavorable anion−π repulsion for the largeranions.
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