Thermal investigation and infrared evolved gas analysis of light lanthanide(III) complexes with pyridine-3,5-dicarboxylic acid

The characterisation of light lanthanide(III) complexes with pyridine-3,5-dicarboxylic acid of the formula Ln2pdc3·nH2O where Ln denotes lanthanides from La to Gd, pdc = C7H5NO42−; n = 6 for Ce(III), n = 7 for Pr(III) and Sm(III), n = 8 for La and n = 13 for Nd(III), Eu(III) and Gd(III) was performed by the thermal analysis TG-DTA and the simultaneous infrared evolved gas analysis TG-FTIR. Heating of the crystalline complexes resulted in the dehydration process at first. Next, dehydrated compounds decompose releasing of CO2, CO, CH4 and hydrocarbons. Free pyridine molecules were detected only in the gaseous products of lanthanum(III) complex decomposition.