The clathrate formation of a series of differently upper-rim-functionalized tetrapropoxycalixarenes has been investigated. In the cases of 5,17-dinitro-, 3, and 5,17-diphthalimidocalixarene, 5, clathrates were obtained with benzene, toluene, p-xylene, and anisole, and for 3 also with o- and m-xylene, mesitylene, chlorobenzene, and nitrobenzene. The clathrate formation of 3 with toluene and p-xylene has been studied with 13C CP-MAS NMR spectroscopy. In the latter case X-Ray analys is at 173 K revealed that the p-xylene is located between the calix[4 ]arenes in channels. X-Ray analysis at 173 K and 13C CP-MAS spectroscopy of the clathrate of tetra-tert-butylcalixarene, 12, and acetonitrile showed that the guest is located in the cavity of the calixarene. In the case of calixarene tetracarbonate, 13, a 1:2 clathrate with acetonitrile was obtained with one guest molecule in- and one out side the cavity.
|Journal||Gazzetta chimica italiana|
|Publication status||Published - 1997|