CONTROLLING CATENATIONS, PROPERTIES AND RELATIVE RING-COMPONENT MOVEMENTS IN CATENANES WITH AROMATIC FLUORINE SUBSTITUENTS

Four new fluorine-containing macrocyclic polyethers based on bis-p-phe nylene-34-crown-10 have been synthesized and subsequently catenated, s eparately, with cyclobis(paraquat-p-phenylene). The efficiencies of th e catenations are strongly influenced by the aromatic ring templates i n the macrocyclic polyethers. Incorporation of fluorine atom substitue nts into one of the hydroquinone rings in bis-p-phenylene-34-crown-10 had only a small effect on the percentage yields, whereas employing bi s-p-phenylene-34-crown-10 derivatives, in which both hydroquinone ring s have been at least partially fluorinated, resulted in a dramatic dec rease in catenation yields. In [2]catenanes incorporating macrocyclic polyethers containing one hydroquinone and one fluorinated hydroquinon e ring, in both the solution (H-1 and F-19 NMR, and UV-vis spectroscop ies, electrochemical studies and molecular modeling) and solid (X-ray crystallography and molecular modeling) states, by far the major trans lational isomers observed were the ones with the hydroquinone ring loc ated ''inside'' the cavity of the tetracationic cyclophane. The dimini shed strength of the noncovalent interactions arising as a result of a romatic fluorine substituents is also reflected in the rates of the mo vements of the two ring components (dynamic NMR spectroscopy). As well as their electron-withdrawing effect, the fluorine substituents have a pronounced effect (UV-vis spectroscopy, electrochemical studies and molecular modeling) on the geometry of the ArO-CH2 bonds within the (f luorinated) hydroquinone rings.