Author/Authors :
Hoffmann، نويسنده , , Anke and Sebastiani، نويسنده , , Daniel and Sugiono، نويسنده , , Erli and Yun، نويسنده , , Sungoo and Kim، نويسنده , , Kwang S and Spiess، نويسنده , , Hans Wolfgang and Schnell، نويسنده , , Ingo، نويسنده ,
Abstract :
When crystallised from water/acetone mixtures, calix[4]hydroquinone (CHQ) forms supramolecular nanotubes which we studied by NMR spectroscopy and DFT calculations, using the 1H and – for the first time – 2H chemical-shift resolution achievable in the solid state under fast (30 kHz) magic-angle spinning. Acetone molecules are trapped in the bowl-shaped CHQ molecules inside the tubes and hydrogen-bonded to an extended chain of hydrogen bonds, which is formed by CHQ and water molecules along the tube axis. Both water and acetone molecules occupy well-defined average positions, but undergo fast reorientation motions during which their protons interchange their positions.