scholarly journals Nuclear spin conversion of water inside fullerene cages detected by low-temperature nuclear magnetic resonance

2014 ◽  
Vol 140 (19) ◽  
pp. 194306 ◽  
Author(s):  
Salvatore Mamone ◽  
Maria Concistrè ◽  
Elisa Carignani ◽  
Benno Meier ◽  
Andrea Krachmalnicoff ◽  
...  
1976 ◽  
Vol 54 (3) ◽  
pp. 239-251 ◽  
Author(s):  
R. F. Code ◽  
J. Higinbotham ◽  
A. R. Sharp

The properties of ammonium perchlorate were investigated in the temperature range between 1.3 and 50 K by nuclear magnetic resonance and relaxation experiments. The observed increase in the proton second moment from its high temperature value of ~ 1.18 G2 to the value of 4.30 G2 below 4.2 K was associated with a characteristic activation energy of ~ 4 × 10−21 J molecule−1 (~ 0.6 kcal mole−1). No evidence could be found for nuclear spin conversion between the symmetry species of the ammonium ion from measurements of the static proton magnetic susceptibility above 1.3 K. An asymptotic analysis of the low temperature proton lineshapes identified the broad wings of the lines with ammonium ions of T type symmetry. Measurements of the proton relaxation times T1 and T1ρ agreed with previous work by others on NH4ClO4, and were similar to observations on other ammonium compounds having low reorientational barriers.


1978 ◽  
Vol 56 (17) ◽  
pp. 2253-2258 ◽  
Author(s):  
Morley Brownstein ◽  
Ronald J Gillespie ◽  
John P. Krasznai

The reactions of IOF5 with SbF5 and with AsF5 have been investigated at low temperature by 19F nmr and Raman spectroscopy. It was found that SbF5 forms labile 1:1 and 2:1 complexes whereas AsF5 forms only a 1:1 complex. The IOF5 is bound through its oxygen atom to the Lewis acids AsF5, SbF5, or (SbF5)2.


Sign in / Sign up

Export Citation Format

Share Document