Examination of the Matrix Isolation Fourier Transform Infrared Spectra of Organic Compounds: Part IV

Abstract

Matrix-isolated (MI) Fourier transform infrared spectra (FT-IR) have been collected on a series of aldehydes and acids. The values for the carbonyl absorption are intermediate between the higher values for vapor-phase (VP) and lower values for solid-state (SS) phases. Substituent effects on aromatic rings induce shifts in carbonyl absorptions in the same manner as found in VP and SS studies. The magnitude of the shifts is approximately the same for all three phases. The spectra reveal a splitting or broadening of the carbonyl absorption for both aldehydes and acids. The size of the molecule affects the degree of band broadening. In certain cases discrete conformers appear to have been isolated in the matrix.