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weight loss, %
112 Chapter 4
100
Cu-BTC
80
60
D3
40
D1
D2
D4
20
100 200 300 400 500 600
T, C
Figure 4.43. TG curves of the prepared Cu-DEMOFs D1-4 in comparison with the parent Cu-BTC.
Metal source: Cu(BF 4 ) 2 6H 2 O. Solvent used for synthesis of the D1 and D2 (blue): DMF; for the D3
and D4 (red): EtOH.
The thermal stability of the all obtained Cu-DEMOF samples D1-4 (Figure 4.43) is
considerable preserved (decomposition temperature equals ca. 300 °C). A little decrease
of thermal stability in comparison with the parent Cu-BTC (decomposition temperature
is ca. 330 °C) might be attributed to the incorporation of ip DL into the MOF structures,
where formation of the defects at Cu2-PW is expected (Figure 4.5). For example, Cu-COO
bonds can be partially substituted by the weak interactions between benzene ring of ip
and Cu-centers in case of defects of type A (modified paddlewheel). In other case (defects
of type B), missing of complete nodes of the Cu2-PWs is probably to happen as well.
Consequently, presence of such defects (either A, B, or both of them) may cause the slight
decrease of the thermal stability of the final DEMOFs.
4.3.1.2 Cu-DEMOFs obtained using Cu(NO3)2·3H2O as metal precursor
The phase purity and crystallinity of all samples D5-8 have been confirmed by the PXRD
analysis of both as-synthesized and activated solids (Figures 4.44 and 4.45). Besides,