SPECTROSCOPIC STUDIES OF HYDROGEN-BOND STRUCTURES AND DYNAMICS OF PARTIALLY METHYLATED P-TERT-BUTYLCALIX[6]ARENES

Hydrogen-bond structures of partially methylated p-teut-butylcalix[6] arenes were investigated both in solution and the solid state by Fouri er transform infrared spectroscopy (FTIR). The hydrogen bonds in these macrocycles are preferentially of the three-centred and cooperative t ypes, The dynamic behaviour of these calix[6]arenes is characterized b y fast rearrangement of the methoxy groups in the calix[6]arene annulu s and was investigated by means of 2D NMR spectroscopy, The conformati onal behaviour is primarily dominated by an interplay of favourable hy drogen-bond formation and the tendency of 'self-inclusion' of the meth oxy groups.