Thermal decomposition mechanism of Ba(DPM)(2)

We have investigated the thermal decomposition behavior of Ba(DPM)(2) using thermogravimetry (TG), mass spectrometry (MS), ultraviolet (UV) absorption and in-situ Fourier transform infrared (FTIR) spectroscopy. FTIR has been used particularly for direct monitoring of the bond dissociation order in t he metal complex by thermal treatment in either N-2 or O-2. TG analysis shows that the ambient gas has a significant effect on the weig ht loss patterns of Ba(DPM)(2). The chemical bonds of Ba(DPM)(2) begin to d ecompose at low temperatures below 50 degreesC and are sequentially dissoci ated when the temperature is raised. The C-C(CH3)(3) and the Ba-O bonds are decomposed most easily at low temperatures, followed by the C-H bond, but the stable C-C and C-O bonds do not dissociate until the total complex is g asified. The decomposition sequence of the chemical bonds in Ba(DPM)(2) is similar to that of Sr(DPM)(2) but differs from that of Ti(O-iPr)(2)(DPM)(2) which is decomposed in the sequence of C(CH3)(3) > C-H and C-O > Ti-O. The major difference in the decomposition sequence between Ba and Ti complexes can be seen to derive from the intrinsic character of the individual metal -oxygen bond as observed by UV spectroscopy.