title: Theoretical and vibrational spectroscopic analysis of the CO stretching mode of cholesteryl alkanoates: the particular case of the cholesteryl acetate.
abstract: Structural and vibrational properties of the CO stretching bond of cholesteryl acetate and related steroids are investigated theoretically and by Micro-Raman spectroscopy. In this work, an analysis of the CO stretching mode for the cholesteryl acetate is presented. Experimental results in crystalline, isotropic liquid and liquid crystal phases are compared with quantum chemical calculations using semi empirical hamiltonians (AM1 and PM3) and the density functional theory. The calculations were performed on isolated molecules with different conformations as found on previous investigations giving strong evidence of their existence. Calculated frequencies are found to be very close to experiments and suggest the possible existence of the predicted conformers.
authors.affiliation: Département des Sciences Exactes, ENSET, BP 1523 Oran El Mnaouer, Algeria.
authors.forename: A
authors.initials: A
authors.lastname: Zanoun
authors.forename: F Hamza
authors.initials: FH
authors.lastname: Reguig
authors.forename: M
authors.initials: M
authors.lastname: Belhakem
authors.forename: A
authors.initials: A
authors.lastname: Krallafa
authors.forename: A
authors.initials: A
authors.lastname: Belaidi
authors.forename: D
authors.initials: D
authors.lastname: Bormann
authors.forename: G
authors.initials: G
authors.lastname: Vergoten
mesh_terms: D000473:Alkanes; D001696:Biomechanical Phenomena; D002248:Carbon Monoxide / Q000737:chemistry*; D002788:Cholesterol Esters / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D013059:Spectrum Analysis, Raman / Q000379:methods; D013314:Stress, Mechanical; D014732:Vibration
chemical_list: D000473:Alkanes; D002788:Cholesterol Esters; D002248:Carbon Monoxide; C060123:cholesterol acetate