Isotropic solid-state MQMAS NMR spectra for large quadrupolar interactions using satellite-transition selective inversion pulses and low rf fields

2021 ◽  
Vol 324 ◽  
pp. 106913
Author(s):  
Ivan Hung ◽  
Zhehong Gan
1994 ◽  
Vol 26 (3) ◽  
pp. 267-271 ◽  
Author(s):  
Koichi Hatada ◽  
Koichi Ute ◽  
Hiroshi Okuda ◽  
F W Hein Kruger ◽  
Otto Vogl

1992 ◽  
Vol 70 (12) ◽  
pp. 2914-2921 ◽  
Author(s):  
Nathalie Dufour ◽  
Anne-Marie Lebuis ◽  
Marie-Claude Corbeil ◽  
André L. Beauchamp ◽  
Pascal Dufour ◽  
...  

Complexes of the types [CH3Hg(aza)], [CH3Hg(Haza)]X, and [(CH3Hg)2(aza)]X are obtained by reacting CH3HgOH and/or CH3HgX (X = NO3, ClO4) with 7-azaindole (Haza). The weakly acidic N1-H proton on the pyrrole ring is displaced by the hydroxide, whereas the perchlorate and nitrate salts lead to CH3Hg+ coordination to the N7 lone pair on the pyridine ring. Detailed analysis of the infrared spectra of the complexes and their N-deuterated derivatives provides diagnostic regions for eventual prediction of the coordination mode in other systems. All compounds are characterized by means of 1H, 13C, and 199Hg NMR spectra in DMSO solution and solid-state CP-MAS 13C spectra. Comparison of the solution and solid-state 13C spectra show that the species present in the solids remain undissociated in DMSO. Each type of complex can be identified from a characteristic pattern of large displacements of the ligand 13C signals. The 1H spectra are less informative because substitution of the N1-H proton by CH3Hg+ induces only minor shifts. Metal solvation appears to have a major influence on the 13C and 199Hg chemical shifts of the CH3Hg+ groups.


1996 ◽  
Vol 86-88 ◽  
pp. 535-538 ◽  
Author(s):  
Masanari Takahashi ◽  
Hiroshi Toyuki ◽  
Masahiro Tatsumisago ◽  
Tsutomu Minami

1997 ◽  
Vol 36 (22) ◽  
pp. 4968-4982 ◽  
Author(s):  
Yangzhen Ciringh ◽  
Scott W. Gordon-Wylie ◽  
Richard E. Norman ◽  
George R. Clark ◽  
Susan T. Weintraub ◽  
...  

1997 ◽  
pp. 255-256 ◽  
Author(s):  
J. F. Green ◽  
K. D. Gwinn ◽  
G. W. Kabalka ◽  
C. L. Anderson

1999 ◽  
Vol 576 ◽  
Author(s):  
H. Kimura ◽  
K. Okita ◽  
M. Ichitani ◽  
M. Yonezawa ◽  
T. Sugimoto

ABSTRACTThe thermosetting mechanism of an organosilicon polymer containing carborane has been studied utilizing the 13and 29Si solid-state NMR method. The polymer having C≡C bonds in the main chain and CH═CH2, Si-H bonds, and carborane in the bulky side chain, shows a very highly thermal stability in air by curing. From 13C and 29Si NMR spectra of the polymer, it was found that the intermolecular cross-linking reactions of the polymer was due to (1) the diene reaction between Ph-C≡C and C≡C and (2) the addition reaction between side chain terminal and Ph-C≡C and between CH═CH2 and Si–H, and a very highly thermal stable structure is formed.


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