ISSN:
1573-1111
Keywords:
Alkalide
;
electride
;
azacage
;
cryptand
;
sodium NMR
;
lithium NMR
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The new lithium-selective complexant 5,12,17-trimethyl-1,5,9,12,17-pentaazabicyclo[7.5.5]nonadecane (TMPAND) was used to synthesize Li+(TMPAND)Na−, the first alkalide prepared from an azacage complexant. This sodide was characterized by a variety of methods. Differential scanning calorimetry experiments showed a reversible, endothermic, solid-solid phase transition at an onset temperature of −75 ± 3°C and with ΔH = 3.3 ± 1 kJ/mol.23Na NMR spectra showed a peak at −61 ppm, characteristic of a sodium anion, and a second minor peak at −10 ppm, probably due to the interaction of Na- with trapped electrons. The quadrupole coupling constant of the complexed lithium cation was found to be 0.19 MHz at −100°C, and7Li NMR spectra showed a discontinuity in the line width of the7Li NMR peak and in the quadrupole coupling constant at the phase transition.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01053867
