Thermal gravimetry, mass spectrometry and solid-state C-13 NMR spectroscopy - simple and efficient methods to characterize the inclusion behaviour of p-tert-butylcalix[n]arenes

摘要

The solid state inclusion of various organic solvent molecules in p-tert-butylcalix[4]arene and p-tert-butylcalix[6]arene has been studied by thermal gravimetry and electron impact mass spectrometry (EI-MS). The host-guest ratio varies from 1 : 2 to 4 : 1 and the nature of included guest has been determined by EI-MS. Thermal gravimetric analysis of solvent-p-tert-butylcalix[n]arene complexes gives a qualitative order of intramolecular forces involved. Structural information obtained by cross-polarization magic angle spinning (CP-MAS) C-13 NMR spectroscopy is in good agreement with known data from single-crystal X-ray diffraction analysis. [References: 46]