Host-guest complex structure
modified crown ethers
Springer Online Journal Archives 1860-2000
Chemistry and Pharmacology
Abstract The twenty-membered macrocycle, 18,19-benzo-1, 16-diaza-4,7,10,13-tetraoxacycloeicosa-17,20-dione, C18H26N2O6 (1), aminosulfuric acid and water form a stoichiometric 1∶1∶1 inclusion compound. The crystal structure of [1·NH 3 + SO 3 − ]·H2O has been determined by X-ray crystallography. The crystal is monoclinic, space groupP21/c, a=7.967(1),b=13.447(3),c=20.779(4) Å, β=90.20(2) Å;Z=4. The finalR-value is 0.0434 for 4638 unique reflections withI〉2σ(I). The structure consists of the 1∶1 molecular complexes between the crown host and aminosulfuric acid revealing hydrogen bonding with the ligand ether and carbonyl oxygen atoms. The complexes are united in the layer-like structure by NH...O host-guest and NH...O=C〈host-host interactions. The water entity forms the second coordination sphere of the compound. Aminosulfuric acid exists in the complex as the zwitterion.
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