AbstractThe water soluble backbone heterometallic polymer {[{(PTA)2CpRu‐µ‐CN‐RuCp(PTA)2}‐µ‐CdCl3]}n (1), which is easily obtained in large amount, was synthesized and its structure determined by single crystal X‐ray diffraction. Coordination‐polymer 1 becomes amorphous when milled under low pressure (0.5 MPa). The amorphous compound was characterized by MAS‐NMR, elemental analysis, TG and Raman spectroscopy. The Raman spectrum of the coordination polymer was assigned by comparison with the Raman spectrum obtained by DFT calculation of a simple model of 1. The analysis of both calculated and experimental Raman spectra showed that Raman spectroscopy can be used to determine if the PTA ligand is mono‐ or bidentate, giving rise to a method for characterization and future studies of polymeric complexes containing bidentate PTA. The phase transformation of 1 under pressure and temperature was studied by PXR, showing how is possible to model easily this Ru‐Ru‐Cd inorganic polymer into a variety of different solid forms with possible new properties.