Two-dimensional correlation analysis of the second overtone of the nu(OH) mode of octan-1-ol in the pure liquid phase

The temperature-induced variations in Fourier transform near-infrared (FT-N IR) spectra of pure liquid octan-1-ol were studied by two-dimensional corre lation analysis. For the first time, the second overtone of the OH stretchi ng band (3 nu (OH)) due to the dimeric species and the splitting of the sec ond overtone of the monomer band arising from the presence of two OH confor mers have been observed. Fourier self-deconvoluted (FSD) and second-derivat ive spectra also confirmed the splitting of the monomer band into two compo nents. It has been demonstrated that positions of the peaks appearing in th e two-dimensional contour maps correlating the first- and second-overtone r egions can be applied for determination of anharmonicity constants. The res ults presented in this paper suggest that the rule saying that the less ass ociated species have the stronger overtones holds on going from the first t o the second overtones as well.