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This thesis presents efforts towards the synthesis and characterization of novel coordination polymers based on cobalt centers and O- and N- donor ligands, with emphasis on investigating potential valence-tautomeric (VT) and spin crossover (SCO) properties. Valence tautomerism constitutes a stimulated electron transfer between a redox-active metal center and a redox-active ligand. The majority of known VT systems are based on Co-dioxolene complexes, where the comparable energies of the frontier orbitals of the Co center and the dioxolene ligand allow the electron transfer to be initiated and controlled by various external stimuli. Spin crossover is a phenomenon occurring for some transition metal complexes, including Co(II), wherein the d electron configuration changes due to an application of an external perturbation. Stimuli used to control VT and SCO transitions are mostly temperature and light, with reported examples of the interconversions controlled by pressure, magnetic field or X-ray. A possibility of being switched between distinguishable electronic states makes VT and SCO complexes potential candidates for data storage, sensor devices and molecular electronics. Results in the field of VT and SCO compounds suggest that coordination polymers (CPs) could show additional interesting properties such as photomechanical effect, host-guest interactions and cooperativity effects. Four one-dimensional (1D) polymeric compounds of general formula {Co(3,5-dbdiox)2(N2L)}∞·S (3,5-dbdiox = 3,5-di-tert-butyldioxolene; N2L = bipyridyl- based ligand: 1,2-bis(4-pyridyl)ethane (1,2-bpe), 4,4-trans-azopyridine (azpy) and 1,3-bis(4-pyridyl)propane (1,3-bpp); S = solvent) have been synthesized and characterized crystallographically. Three compounds show a trans disposition of the nitrogen-donor ligands around the cobalt center, while the compound based on flexible 1,3-bpp consists of two types of chains, cis and trans. All compounds undergo thermally-induced VT transitions and in