Infrared spectra of phenol and its chloro-substituted derivatives in low-temperature argon matrices were measured with an FTIR spectrophotometer. The observed spectra were analyzed with an aid of density functional theory where the B3LYP/6-31G* calculation level was used. A comparison between observed and calculated vibrational wavenumbers showed that the consistency depends on number and position of chlorine atoms.
Vibrational frequencies and infrared intensities of water dimer, trimer, tetramer and pentamer have been calculated with ab initio and density functional methods. Onsager model was also utilized to obtain the frequencies and infrared intensities in the liquid water as the solvent. Calculated spectra were compared with the FT-IR spectrum of liquid water. The presence or absence of water clusters in the liquid water has been discussed. The calculated stretching frequencies of the cyclic tetramer and pentamer indicated that these species are by no means the main structure of the liquid water at least qualitatively.
Structures and characters of adsorbed oxygen species on Ag (110) and Ag (111) surfaces have been studied by the AM1-d method in WinMOPAC. There are two types of adsorbed atomic oxygen species, O(ad)_4-coordinate-site and O(ad)_3-coordinatesite on Ag (110), only O(ad)_3-coordinate-site on Ag (111), but no adsorbed molecular oxygen species on Ag (110) or Ag (111). The AM1-d calculation results about the characters of adsorbed oxygen species qualitatively agree with the ab initio calculation results and experimental results in literatures. Ag parameter in WinMOPAC is usable for cluster calculations.
The relative sensitivity of phenacylesters and steroids measured by chemiluminescent detection in liquid chromatography using luminol was analyzed by their properties calculated using computational chemistry. The important reaction process was considered as the keto-enol form rearrangement. The partial charge of carbon atoms of carbonyl group changed significantly and correlated well with the relative sensitivity. The correlation coefficient (r2) was 0.970 (n=5) and 0.965 (n=8) for phenacylesters and steroids, respectively.