Quantitative Analysis of Infrared Spectra of Binary Alcohol + Cyclohexane Solutions with Quantum Chemical Calculations

Abstract

Hydrogen bonding has profound effects on the behavior of molecules. Fourier-transform infrared spectroscopy is the technique most commonly used to qualitatively identify hydrogen-bonding moieties present in a chemical sample. However, quantitative analysis of infrared (IR) spectra is nontrivial for the hydroxyl stretching region where hydrogen bonding is most prominently expressed in organic alcohols and water. Specifically, the breadth and extreme overlap of the O–H stretching bands, and the order of magnitude variability of their IR attenuation coefficients complicates the analysis. In the present work, sequential molecular dynamics simulations and quantum mechanical calculations are used to develop a function to relate the integrated IR attenuation coefficient to the vibrational frequencies of hydroxyl bands across the O–H stretching region. This relationship is then used as a guide to develop an attenuation coefficient scaling function to quantitatively determine concentrations of alcohols in a hydrocarbon solution from experimental IR spectra by integration across the entire hydroxyl frequency range.

Breaking through the Separation Barrier of Zr(IV) and Hf(IV): Magical Effect of the Bisamide Ligand

“…Figure shows the FT-IR spectra of D001, octanol, and complex. The characteristic peaks attributable to C–OH and OH in octanol are found at 1036 and 3338 cm –1 . The hydrogen atom on the nitrogen atom of tertiary amide D001 is completely replaced, so there is no hydrogen bond association between molecules.…”

“…The characteristic peaks attributable to C−OH and OH in octanol are found at 1036 and 3338 cm −1 . 49 The hydrogen atom on the nitrogen atom of tertiary amide D001 is completely replaced, so there is no hydrogen bond association between molecules. At 1632 cm −1 of D001, a typical C�O stretching vibration peak corresponding to the amide I band can be found.…”

Wertheim’s Association Theory for Phase Equilibrium Modeling in Chemical Engineering Practice

“…Interpretations even into the early 2000s hypothesized that monomer, dimer, and polymer contributed to the absorbance, but instead the hydrogen bond configuration is important and every dimer and chain has a unbonded proton at the end and every polymer chain shares the same end configurations as a dimer. Quantum chemical calculations demonstrate that the solvated protons at the end of chains exhibit the same frequency and IR absorbance intensity as the unbonded configuration . Thus, the majority of spectroscopic interpretations available in the literature that rely on the monomer, dimer, polymer assumption are suspect.…”

“…Another complication is that the attenuation coefficient used to quantify hydroxyl concentration increases by a factor of approximately 35 compared to free protons for the most strongly bound protons, 231 meaning that a single attenuation coefficient cannot be used for quantification of hydroxyl configurations. The attenuation coefficients have conventionally been approximated for bonded hydroxyl configurations, typically as a constant for each hydroxyl configuration.…”

Partial and Аpparent Мolar Volume of Аzithromycin in Its Solutions in Еthanol, 1-Рropanol, and 1-Butanol at 300.15, 305.15, 310.15 K and Ambient Pressure

“…Alcohols are widely used as solvents in chemical and pharmaceutical industries, during extraction [6][7][8], as dispersing agents for nanomaterials [9][10][11][12] and for the synthesis of other organic compounds [13][14][15][16]. A large number of studies devoted to alcohols and their mixtures at various temperatures and pressures have been carried out using densimetry, viscometry, spectroscopy, and computer chemistry [17][18][19][20][21][22][23][24][25][26][27][28][29]. In clinical medicine, undesirable drug-alcohol interactions are of common concern [30].…”