A novel synthetic concept is presented which allows, for the first time, the preparation of soluble, constitutionally well-defined transition-metal coordination polymers of considerable molecular weights from kinetically unstable, pseudotetrahedral copper(I)- and silver(I)-phenanthroline complexes. It is demonstrated that rigorous exclusion of all molecules that might act as competitive ligands for the metal ions of the polymer constitutes the central requirement for obtaining solutions of “proper” coordination polymers, i.e., polymers having a constant number of repeating units per individual chain. Tetrachloroethane was found to be an appropriate solvent for this purpose. Solubility of the copper(I) and silver(I) coordination polymers – which are polyelectrolytes – in this rather apolar solvent was achieved by the attachment of two hexyl side chains to each polymer repeating unit. It was thus possible to prove the defect-free constitution of the obtained coordination polymers and to show their excellent stability in solution with the aid of 1H and 13C NMR spectroscopy. Moreover, formation of coordination polymers of considerable chain lengths is supported by the complete disappearance of end-group absorptions in the 1H NMR spectra and the results of viscosimetric investigations.