Polyurethane–epoxy based azopolymers: Influence of chemical structure over photoinduced birefringence

Unprecedented high-temperature CO2 selectivity in N2-phobic nanoporous covalent organic polymers

“…The formation of azo-COPs was revealed by Fourier transform infrared spectroscopy (FTIR), elemental analysis, cross-polarization magic-angle spinning (CP/ MAS) 13 C NMR and ultraviolet-visible spectroscopies (Supplementary Figs S1-S3). The characteristic stretching band for -N ¼ N-functionality in the FTIR spectrum is clearly visible at 1,447 and 1,403 cm À 1 along with the respective bands for aromatic rings 33 . The FTIR bands located at 1,520 and 1,340 cm À 1 correspond to N-O stretching mode, suggesting the presence of unreacted terminal nitro groups.…”

Azo-functionalized microporous organic polymers: synthesis and applications in CO2 capture and conversion

“…The formation of Azo-MOP-N (N=1~4) was revealed by Fourier transform infrared (FTIR) spectroscopy, and crosspolarization magic-angle spinning (CP/MAS) 13 C NMR. In the FTIR spectra ( Figure S3, ESI), the structures of -N=Nfunctionality were confirmed by the characteristic bands at 1147 and 1403 cm -1 due to the symmetric and asymmetric vibrations of the azo group, 10a along with the respective bands for C-N stretching vibration (1280 cm -1 ) and aromatic rings (1450, 1500, 1580 and 1600 cm -1 ).…”

“…The FTIR bands located at 3437 and 3200 cm -1 corresponded to N-H stretching mode, suggesting the presence of unreacted terminal amino groups. 13 After coordinating with RuCl 3 ·3H 2 O, the stretching vibration for Ru-Cl bond (1076 cm -1 ) and bending vibration for the bound H 2 O molecule in RuCl 3 ·3H 2 O (1609 cm -1 ), was observed in the FTIR spectra of the obtained Azo-MOP-N-Ru (N=1~4) ( Figure S4, ESI). The presence of chemical shifts in CP/MAS 13 C NMR spectra ( Figure S5, ESI) of Azo-MOP-N (N = 1~4) located in the range of 113.3~152.1 ppm belonged to the aromatic carbons in the backbone, thus confirming the formation of the azo-linked aromatic polymers.…”

Directing two azo-bridged covalent metalloporphyrinic polymers as highly efficient catalysts for selective oxidation

“…2, in order to monitor the variations in the functional groups. The characteristic stretching band for N N functionality in the FT-IR spectrum was clearly visible at 1447 cm −1 along with the respective bands for aromatic rings [31]. Additionally, the FT-IR bands located at 1520 and 1340 cm −1 correspond to N O stretching mode, suggesting the presence of unreacted terminal nitro groups.…”