2015: Monitoring the alcoholosis of isocyanates with infrared spectroscopy

Kössl, F; Lisaj, M; Kozich, V; Heyne, K; Kühn, O;

Chemical Physics Letters 2015, 621, p. 41-45;

The alcoholysis reaction of phenylisocyanate with cyclohexanol (I) and of 2,4-toluene-diisocyanate withchloraldhydrate (II) is studied by infrared absorption spectroscopy in combination with anharmonicfrequency calculations using density functional theory. It is shown that the progress of the reaction canbe monitored by measuring infrared marker bands in the isocyanate NCO and alcohol OH stretchingregions. Analysis of spectra obtained as a function of time for different temperatures yields a second-order kinetics with an Arrhenius activation energy of 6.7 ± 0.2 and 2.8 ± 0.3 kcal/mol for reaction I and II, respectively.