Figure 2 (a) TGA curve of Ni(TMBDC)(DABCO)0.5; (b) PXRD
patterns of Ni(TMBDC)(DABCO)0.5 before and after various
treatment.
TGA data were collected for the evaluation of the thermal stability of
the Ni(TMBDC)(DABCO)0.5. Figure 2(a) presents the TGA
curve of Ni(TMBDC)(DABCO)0.5. It is noticed that the TGA
curve showed a negligible weight loss (~5%) before 400
ºC which was attributed to the removal of guest molecules such as
H2O molecule. After 400 °C, a great weight loss
(~68%) occurred due to the decomposition of the
framework structure. It suggests that the
Ni(TMBDC)(DABCO)0.5 is thermally stable until 400 ºC.
We also examined the solvent stability and water vapor stability of the
Ni(TMBDC)(DABCO)0.5. Figure 2(b) shows the PXRD patterns
of Ni(TMBDC)(DABCO)0.5 before and after soaking in
various solvents or exposure to humid air for several days. It is
visible that the Ni(TMBDC)(DABCO)0.5 retained the
structural integrity after soaking separately in acetone, DCM, Hexanes
for 4 days and ethanol for 20 days, demonstrating excellent stability in
these organic solvents. Furthermore, the water vapor stability was
tested by exposing the Ni(TMBDC)(DABCO)0.5 to humid air
with 55% and 100% humidity for 4 days. The PXRD patterns of
Ni(TMBDC)(DABCO)0.5 after exposure to humid air are
similar to that of the fresh material, suggesting its excellent humid
stability. The water vapor stability could be attributed to the
hydrophobicity of the channel of Ni(TMBDC)(DABCO)0.5,
which is caused by the methyl group on the TMBDC ligand and the
methylene group on the DABCO ligand.