Calculation Of Gauss Solvent Effect For In Situ Infrared

Solvent effect refers to the chemical and physical properties change of the same material in different solvents, due to the solute-solvent interaction between the solute and solvent. Study the mechanism of the solvent effect plays an important role in many aspects, such as the reaction activity and spectrum properties of organic compounds and the chemical physical properties of the solution. Therefore, the solvent effects research is always be the hot research topic in chemical field.The combination method of FTIR and five kinds of solvent parameters was used to study the solvent effect of benzaldehyde, trying to find the suitable parameter to research the solvent effect through studying the changing rule of the benzaldehyde carbonyl vibration frequency in single-solvent systems. Comparing the correlation results between five different parameters and benzaldehyde carbonyl vibration frequency, it shows that the correlation between V(c=o) and G was the best one, and the next was the one with S, the results of the correlation between V(c=o) and AN、DN、 ET(30) was relatively poor. All the parameters have limitations, and the parameter G can only be used in describing non-specific interactions.The density functional theory B3LYP/6-31G*method was chosen to calculate the infrared spectrum of benzaldehyde in gaseous state. The electrostatic effects of different solvents in benzaldehyde solutions were calculated using the self-consistent isodensity polarizable continuum model (SCI-PCM). Ab initio calculation was used to compute the hydrogen bonding between benzaldehyde and ethanol molecules. The interaction mechanism between benzaldehyde and solvent was discussed at the theoretical level, it gives excellent agreements with FT-IR spectra of title compound in solutions.Based on the study of benzaldehyde solvent effect, the silicon hydrogen bond stretching vibrations (v(Si-H)) of1,1,3,3-Tetramethyldisiloxane in each solvent were correlated with solvent parameter G. In situ-IR, GC and GC-MS were used to monitoring the silicon hydrogen addition reaction of the heptamethyltrisiloxane and allyl glycidyl ether. Comparing the reaction time, products and completion reaction degree of different systems to probe into the solvent effect of the silicon hydrogen addition reaction. The best solvent was chosen by comprehensive comparison, it gives guideline for chosing the suitable silicon hydrogen addition reaction solvent.