화학공학소재연구정보센터
Journal of Physical Chemistry A, Vol.111, No.10, 1792-1799, 2007
Double quantum H-1 MAS NMR studies of hydrogen-bonded protons and water dynamics in materials
Two-dimensional double quantum (DQ) H-1 MAS NMR was used to investigate different proton environments in a series of alkali (Na, K, Rb, Cs) [Nb6O19](8-) Lindqvist salts, with the water and hydrogen-bound intercluster protons being clearly resolved. Through the analysis of the DQ H-1 NMR spinning sideband pattern, it is possible to extract both the mean and distribution of the motionally averaged intramolecular homonuclear H-1-H-1 dipolar coupling for the different water environments and the intercluster protons. Motional order parameters for the water environments were then calculated from the averaged dipolar couplings. The influence of additional intermolecular dipolar couplings due to multispin interactions were simulated and discussed.