Is [N+-H...O] hydrogen bonding the most important noncovalent interaction in macrocycle-dibenzylammonium ion complexes?
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.
Cheng
Pin-Nan
PN
Department of Chemistry, National Taiwan University, Taipei, Taiwan, ROC.
Huang
Po-Yi
PY
Li
Wan-Sheung
WS
Ueng
Shau-Hua
SH
Hung
Wei-Chung
WC
Liu
Yi-Hung
YH
Lai
Chien-Chen
CC
Wang
Yu
Y
Peng
Shie-Ming
SM
Chao
Ito
I
Chiu
Sheng-Hsien
SH
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
D050339:Benzylammonium Compounds; D047028:Macrocyclic Compounds