42-crown-14-based [2]catenane

A compound isolated from a synthesis directed toward 42-crown-14 (42C14) ha s been purified and characterized by means of IR, HPLC, NMR, MS, and DSC te chniques. Its infrared spectrum contains no OH, tosylate, or unsaturated un it signals. The HPLC retention time of the compound differs from that of "4 2C14" and other crown ethers examined. The chemical shifts of the singlets in the H-1 and C-13 NMR spectra differ from those of poly(ethylene oxide)s (PEOs), and crown ethers. The FAB mass spectra contain signals attributable to a compound with twice the mass of 42C14 and the fragmentation pattern i s consistent with [2]catenane 9 based on interlocked 42C14 units, because t he next major signals generally correspond to 42C14 and its adducts. The DS C results showed that the compound, a colorless wax at room temperature, wa s amorphous with a glass transition temperature which was 80% higher than t hose of aliphatic crown ethers, which are crystalline compounds with meltin g points > 40%C. Considering the high yield of the compound (8% in the reac tion mixture as determined by NMR, 1.7% isolated), it is believed that sodi um cation-crown ether-linear ether complexation was involved in templating its formation. Evidence for such complexation was also observed in the FAB MS.