resolver

Chapter 3 39
Figure 3.9. IR spectra of the activated Ru-MOFs before (1-4) and after “solvent exchange” (1-
4_ex).
The PXRD patterns of the samples 1-4_ex match well with those of the [Cu3(BTC)2]n,
suggesting fully preserved structural integrity of the Ru-frameworks after employed
solvent exchange procedure (Figure 3.8). The IR spectra of the 1-4_ex further substantiate
that the structure of the Ru-MOFs is retained (Figure 3.9). Both reveal the chemical
stability of the 1-4 after solvent exchange. As expected, the amount of residual guest
molecules (in this case, acetic acid, etc.) hosted by the frameworks of 1, 2 and 3 decreases
considerably after applying an additional “solvent exchange”, which is clearly indicated
by the comparison of the 1 H-NMR data of the digested and activated Ru-MOFs samples
before (1-3) and after solvent exchange (1-3_ex) (Table 3.1 and Figure 3.6). In fact, the
integration of the signals attributed to AcOH (δ = 1.88-1.93 ppm) in 1_ex and 1
corresponds to 0.8:1 vs. 2.4:1. Notably, pivalic acid in 2 was removed even to a greater