Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
116 Chapter 4<br />
4.3.2 Composition and porosity of the prepared Cu-DEMOFs<br />
In order to determine the presence and amount of the framework incorporated DL ip in<br />
the Cu-DEMOF solids, 1 H-NMR spectroscopic measurements have been performed on all<br />
activated samples (which were previously acid-digested). Apart from the resonance at ca.<br />
8.6 ppm, which originates from the aromatic protons of BTC, three additional peaks<br />
appear at ca. 7.6, 8.1 and 8.4 ppm in all Cu-DEMOF samples D1-8 (Figures 7.15-7.22),<br />
which could be attributed to the aromatic protons of ip DL. The ratio of incorporated ip to<br />
the total linkers-amount (BTC+ ip) in the obtained solids have been estimated from the<br />
integrals of the proton resonances in 1 H-NMR spectra and are listed in Table 4.9.<br />
Table 4.9. The incorporation of ip (calculated from the integration of proton-signals in 1 H-NMR<br />
spectra) and BET surface area (estimated from the N 2 sorption experiments (at 77 K)) of the<br />
obtained Cu-DEMOFs.<br />
Samples<br />
Metal source<br />
Synthesis<br />
solvent<br />
Molar ratio of ip : (BTC + ip)<br />
feeding<br />
incorporation<br />
(obtained)<br />
S BET (m 2 /g)<br />
D1 Cu(BF 4 ) 2·6H 2 O DMF 1/2 20% 1833<br />
D2 Cu(BF 4 ) 2·6H 2 O DMF 2/3 25% 2030<br />
D3 Cu(BF 4 ) 2·6H 2 O EtOH 1/2 12% 1931<br />
D4 Cu(BF 4 ) 2·6H 2 O EtOH 2/3 17% 1973<br />
D5 Cu(NO 3 ) 2·3H 2 O DMF+HBF 4 1/2 23%, 28%* 1841, -*<br />
D6 Cu(NO 3 ) 2·3H 2 O DMF+HBF 4 2/3 33%, 33%* 1305, 2030*<br />
D7 Cu(NO 3 ) 2·3H 2 O DMF 1/2 21% 1818<br />
D8 Cu(NO 3 ) 2·3H 2 O DMF 2/3 30% 1673<br />
* reported values in the literature. [140]<br />
On the whole, it might be concluded, that both metal salts that have been tested in present<br />
studies could be successfully utilized to introduce ip DL into Cu-BTC. Curiously, addition<br />
of HBF4 increases the amount of the incorporated ip (in about 2-3%) when Cu(NO3)2·3H2O<br />
is utilized. However, on the basis of the performed quantitative calculations and taking<br />
into account an error of integrals of the 1 H-NMR signals, this difference might be ignored.<br />
Hence, the incorporation amount of ip in the reproduced sample D5 can be also<br />
considered to be same as the reported values (Table 4.9). [140] In the case of usage<br />
Cu(BF4)2·6H2O, the reaction in DMF yields to higher extent of ip incorporation (about 8%
Change language