IR SPECTRA, METHYLENE CHAIN VIBRATIONS AND ROTATIONAL ISOMERISM OF n-ALKYL TRICHLOROACETATES

Article abstract of DOI:10.1016/0022-2860(88)87005-4

IR spectra of ten n-alkyl trichloroacetates CCl3COO(CH2)nCH3 (R'-TCA) in the crystalline state (R'-TCAs with n=4, 5 in the glassy state) have been studied.End-group (CCl3COO-) vibrations have been assigned by referring to the previous results for methyl and ethyl analogs and four methylene band progressions have been analyzed.Interaction between methylene and end-group vibrations is discussed.It is suggested that in the crystalline state the nP-TCA (n=2) molecule takes a gauche conformation only in O-CH2-CH2CH3 group and the other R'-TCA molecules adopt the all-trans extended form relative to skeletal rotational axes.