The temperature-induced formation of an intermediate modification (the precursor of the tetranuclear oxo complex) of straight-chain zinc carboxylates (even numbered between C6 and C18) was studied by means of temperature-dependent Fourier transform infrared spectroscopy and differential scanning calorimetry. The formation of this intermediate modification required only low interaction between the alkyl chains, which could be caused by temperature, solvent or geometric incompatibility. The infrared spectra proved that rearrangement of the carboxylate groups and destruction of the all-trans arrangement of the alkyl chains occurred simultaneously during the solid-liquid transition of the samples. A simple linear model was employed to interpret the measured enthalpies and the calculated entropies. The enthalpy contributions of the alkyl chains predominated in the transitions between the different modifications and in the formation of the polymeric sheet structure of the straight-chain zinc carboxylates.
- Differential scanning calorimetry
- Infrared spectrometry, temperature-dependent Fourier transform
- Zinc carboxylates, straight-chain
ASJC Scopus subject areas