Modern coordination chemistry increasingly turns to metal compounds with versatile ligands, special emphasis being recently paid to heterometallic complexes that exhibit a wider range of valuable properties compared to homometallic complexes. The preparation of multimetallic complexes enables their nanoscopic dimensions to be combined with cumulative action and can lead to novel or enhanced valuable properties. The basic task of the research was to get heterometallic complexes with higher 4f-luminescence quantum yield than in the corresponding homometallic complexes. It was reported that Bi(III) can be used as a sensitizer of luminescence of lanthanides in the visible and near-infrared (IR) spectral region [1, 2]. Heterometallic compounds can be also considered as molecular precursors for mixed-oxides upon adequate thermal treatment. We proposed to investigate the impact of the chlorine source and of the heating rate on the composition and morphology of the final residues. Considering these, five heterometallic compounds of general formula Pr{Bi(cdta)}3-yXy·zH2O (X = CH2ClCOO-, CHCl2COO-, CCl3COO-, ClO4-, Cl-; y = 1 or 2; z = 9 - 14; cdta4- = 1,2-cyclohexanediamintetetraacetate) have been synthesized and analyzed. The composition of the complexes has been determined by means of elemental analysis, thermogravimetry, IR spectrometry and single crystal X-ray diffraction. The crystal structures of the compounds represent two-or three-dimensional networks, with Bi(III) having a coordination number of 8 while praseodymium coordination number is 8, 9 or 10. The ligands 1,2-cyclohexanediamintetetraacetate are coordinated to Bi(III) ions through the 2N+4O atom sets. The coordination is completed to eight by bridging oxygen atoms of cdta4- or Cl- ions. The coordination sphere of Pr(III) is formed of water molecules, bridging oxygen atoms of cdta4- ligands and dichloro- or trichloroacetate ions. Non-ionized and non-coordinated dichloro- or trichloroacetic acids are also present in two structures. Thermogravimetric analysis results confirmed that at 0.5oC·min-1 heating rate the residue masses are in good agreement with the calculated values for the corresponding precursors. Notably, some residues represent heterometallic oxychlorides, while others are mixes-oxides thought all the precursors have chlorine in the composition. Accordingly, the appearance of the thermolysis products differs from precursor to precursor depending on the chorine source. It was determined that the heating rate affects the morphology of the residues. So, the products resulted after thermal treatment of the precursors at 10 oC·min-1 heating rate are formed of smaller grains than those eventually obtained at 0.5 oC·min-1.