Complexation Equilibria Involving Salts in Non‐Aqueous Solvents: Ion Pairing and Activity Considerations
作者:Harry W. Gibson、Jason W. Jones、Lev N. Zakharov、Arnold L. Rheingold、Carla Slebodnick
DOI:10.1002/chem.201002522
日期:2011.3.7
cations and even ionpairs is now an active area of investigation in supramolecular chemistry; unfortunately it is an area fraught with complications when these processes are examined in lowpolarity organic media. Using a pseudorotaxane complex as an example, apparent Ka2 values (=[complex]/[salt]o−[complex]}[host]o−[complex]}) for pseudorotaxane formation from dibenzylammonium salts (2‐X) and dibenzo‐[24]crown‐8
pseudorotaxane. Integration of pertinent signals allowed the associationconstants of pseudorotaxanes to be determined readily. Among the [22-30]crown ethers, the highest value of the associationconstant was that for the [24]crown ether/dibenzylammonium ion system; the [25-30]crown ether/ammonium ion systems exhibited moderate values of their associationconstants [K exp = 35-114 M -1 when using (ArCH 2 ) 2 NH