Temperature-induced release of crystal water in the Co, Mo and Pt complexes of N,N-diacetatedithiocarbamate. FTIR spectroscopy and quantum chemical study

• M06-2X calculations are used for prediction of IR spectra of metal dithiocarbamates.
• Temperature-dependent IR spectra of dithiocarbamato-based complexes are presented.
• Temperature dependence of HB network within polycrystalline samples is exhibited.
• Different behavior of hydrogen-bonded and free water is observed.

We describe temperature-induced water release from the complexes of triammonium N,N-diacetatedithiocarbamate (dadtc) with Co(III) (1), Mo(VI) (2) and Pt(II) (3), by the combination of temperature-dependent IR spectroscopy and quantum chemical calculations. Transmission IR spectra show that in the compounds 1 and 2, where water molecules are hydrogen-bonded with complex moieties, water release occurs at about 80 °C. In the compound 3 water most probably exist as non-hydrogen-bonded and remains within the sample above 100 °C. The influence of an inert salt in maintaining the water and consequently bringing up the artefacts in spectra is eliminated by recording the spectra in the internal reflection regime (ATR). Possible interplay of water release from the samples 1 and 2 and samples phase transition is presumed and indicated by the baseline analysis of temperature-dependent transmission IR spectra.

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