ABSTRACT
Vibrational analysis of the two conformers of furfural and 2-chlorobenzaldehyde has been carried out on the basis of their IR and Raman spectra measured in isotropic and anisotropic (nematic liquid crystalline) solvent. The average orientation of the individual conformers in the nematic solvent has been determined by means of a recently developed approach for low symmetry planar molecules using DFT calculations of the vibrational transitions moments. The complex shape of the carbonyl band additionally split into several components is interpreted as an effect of Fermi resonance.
Subject(s)
Benzaldehydes/chemistry , Furaldehyde/chemistry , Spectrophotometry/methods , Carbon/chemistry , Fourier Analysis , Models, Chemical , Models, Statistical , Molecular Conformation , Software , Spectrophotometry, Infrared/methods , Spectrum Analysis, Raman , VibrationABSTRACT
The infrared absorption spectra of 2-[4-( N -dodecanoylamino)phenyl]-5-(4-nitrophenyl)-1,3,4-oxadiazole (also denoted AF51) in solution and in the solid state as well as the solid-state Raman spectrum of the powdered compound are compared with the infrared linear dichroic (LD) spectra recorded at two orthogonal polarizations. The IR-LD spectra were measured in an anisotropic solvent-the nematic liquid crystal ZLI-1695 (Merck). The solvent spectrum taken under precisely the same experimental conditions and polarized radiation azimuths was subtracted from the polarized sample spectra in order to achieve pure oriented spectra of the compound studied. These spectra were further processed using a stepwise reduction procedure that allows for assignment of vibrational modes having mutually orthogonal dipole moments.
ABSTRACT
Two clinical cases are presented in the paper with one of the most common defects of dentitions as an indication for implantation-prosthesis--the absence of the upper central incisors as a results from acute trauma. A good functional and aesthetic effect has been attained. The constructions are in good order and have no changes in the teeth and implants during the almost two-year period.
Subject(s)
Dental Implants , Tooth Avulsion/rehabilitation , Adult , Dental Implantation, Endosseous/instrumentation , Humans , IncisorABSTRACT
New esters of the ethan phosphonic acids have been synthesized and their extraction properties studied with respect to Mo(VI), Re(VII), Fe(III),Au(III),Tl(III) and Sb(V). A possibility is shown for the analytical separation of molybdenum from rhenium (beta = 700). The state of these new extraction agents in carbon tetrachloride solution, and the mechanism of the extraction processes, have been investigated by means of infrared spectra.
