Understanding the VOC sorption processes on fluoro alkyl substituted phthalocyanines using ATR FT-IR spectroscopy and QCM measurements

The role of hydrogen bonding in the sensitivity of QCM sensors: A spectroscopic study on tosylamido phthalocyanines

“…Furthermore, the band at 3066 cm −1 attributed to the aromatic C H groups is very small in intensity and has also the shape of a derivative function, which is interpreted as a weak interaction between the acetonitrile molecules and the aromatic C H groups. The type of interaction was also observed in the previous experiments with fluoropropoxy Pcs [13]. However, the intensity of the bands is relatively low in the case of tosylamido substituted phthalocyanine indicating that the number of aromatic C H groups interacting with the system of acetonitrile is lower.…”

“…The coating process, the characterization of the films in various atmospheres using ATR and QCM techniques as well as the automated gas mixing system to produce the gas vapours are described in detail in [13].…”

“…Difference spectroscopy as a spectroscopic data evaluation method is used for identification of the parts of the Pc molecule interacting with VOCs [13]. Difference spectra were created by the subtraction of the spectra recorded at a certain humidity level in analyte free carrier gas from the spectra recorded during VOC exposure at the same humidity level (S voc, x%RH − S x%RH ).…”

“…Although various gas sorption studies have been performed on sensors based on phthalocyanine sensing layers only very few investigations into the sensing mechanism are reported [5,6,[9][10][11][12][13][14][15][16]. Vibrational spectroscopy, especially attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR), serves as a suitable technique for the determination of the structure of phthalocyanine thin layers and for the understanding of the analyte-Pc interaction on the molecular level [3,15,16].…”

Effects of humidity on the electrical properties of thermal inkjet-printed films of copper tetrasulfonated phthalocyanine (CuTsPc) onto paper substrates

“…Regarding humidity effects, Bohrer et al observed electrical current changes on cobalt and metal-free phthalocyaninebased chemiresistors due to the device exposure to water vapor, whereas Karimov and co-workers registered capacitance changes on copper phthalocyanine-coated electrodes for different RH values [51,52]. According to Bohrer et al vapor molecules in general interact at phthalocyanine free sites but can also compete for O 2 -bound sites [51,[53][54][55] and Karimov et al expect that water molecules can act as p-type dopants in MPcs similar to the O 2 effect [52]. Harbeck et al, using quartz crystal microbalance sensors and Fourier transform infrared (FTIR) spectroscopy, observed that water sorption in fact occurs at the core of substituted MPcs as well as weak hydrogen bonds in N-H groups of metal-free phthalocyanines [54].…”