title: Is [N+-H...O] hydrogen bonding the most important noncovalent interaction in macrocycle-dibenzylammonium ion complexes?
abstract: We report a new host molecule in which one diethylene glycol chain (i.e., a loop possessing only three oxygen atoms) incorporated along with two phenolic aromatic rings is linked by a xylene spacer into a macroring. The design of the molecular structure of this macrocycle "amplifies" any potential [cation...pi], [N+-H...pi], and [N+C-H...pi] interactions between the dibenzylammonium (DBA+) ion and the phenolic rings of the macrocycle; as such, these species display a very strong binding affinity in CD3NO2 (Ka = 15,000 M(-1)). The macroring also coordinates to bipyridinium ions in a [2]pseudorotaxane fashion, which makes it the smallest macrocycle (i.e., a 25-membered ring) known to complex both DBA+ and bipyridinium ions in solution. To confirm unambiguously that these pseudorotaxanes exist in solution, we synthesized their corresponding interlocked molecules, namely rotaxanes and catenanes.
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, Taiwan, ROC.
authors.forename: Pin-Nan
authors.initials: PN
authors.lastname: Cheng
authors.forename: Po-Yi
authors.initials: PY
authors.lastname: Huang
authors.forename: Wan-Sheung
authors.initials: WS
authors.lastname: Li
authors.forename: Shau-Hua
authors.initials: SH
authors.lastname: Ueng
authors.forename: Wei-Chung
authors.initials: WC
authors.lastname: Hung
authors.forename: Yi-Hung
authors.initials: YH
authors.lastname: Liu
authors.forename: Chien-Chen
authors.initials: CC
authors.lastname: Lai
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Shie-Ming
authors.initials: SM
authors.lastname: Peng
authors.forename: Ito
authors.initials: I
authors.lastname: Chao
authors.forename: Sheng-Hsien
authors.initials: SH
authors.lastname: Chiu
mesh_terms: D050339:Benzylammonium Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D006860:Hydrogen Bonding; D047028:Macrocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D012680:Sensitivity and Specificity; D013237:Stereoisomerism
chemical_list: D050339:Benzylammonium Compounds; D047028:Macrocyclic Compounds