Carbonyl groups not involved in hydrogen bonding show absorption bands that were observed near 1723 cm−1, and carbonyl bands associated with poorly ordered hydrogen bonding were observed at 1710 cm−1.
The formation of separate phases of Si O and Si N bonds was observed at high fluence level (≅ 2 × 1018 ions-cm− 2).
While formation of the thin films composed of single-layer graphene nanosheets with minimum thickness of 0.37 nm and nearly without any functional group bonds was observed at the high temperature of 1000 °C in the one-step reducing procedure, similar high quality graphene thin films were obtained at the lower temperature of 500 °C in our two-step reducing temperature.
Furthermore, the short-distance hydrogen bonds, which is assumed to be so-called "low-barrier hydrogen bond", were observed at CDRs in three complexes.
Vibrational modes of metal-sulfur bonds were observed at wave numbers below 1000 cm−1 in the Fourier transform infrared spectrum at room temperature.
Instead, the signals for an additional double bond are observed at δH/δC 6.27/145.8 and 6.36/129.1 ppm, with a J = 5.4 Hz typical for a 5-membered endocyclic coupling.
That is, about 70% of the hydrogen bonds were observed at CDRs of the heavy chain and also the direct hydrogen bond with the shortest distance mainly existed at the loops of the heavy chain for all the complexes.
A peak attributed to π π* shake-up bonds is observed at 290.4 eV [20, 26]; and the peak at 283.2 eV originates from carbidic carbon [27].
The bending vibrations of the C-O-H bond were observed at 1202 and 1188 cm-1 (calculated and experimental IR and Raman spectra, respectively), too.
The asymmetric and symmetric stretching of CH bonds are observed at 2,927 and 2,853 cm-1, respectively and the stretching of C = O of the carboxylic acid (-COOH) group is observed at 1,734 cm-1.
