The objective of the PhD Thesis is to develop and explore new molecular homogenous and heterogenous catalysts for the reduction of carbon dioxide and low-weight organic derivatives. The synthesized compounds will be characterized by various spectroscopic techniques. Special emphasis will be placed on the spectroelectrochemical characterization (IR, UV-Vis-NIR) of intermediates for full understanding of the mechanisms. Immobilization of the most promising molecular catalysts onto conductive support (electrode) will be also developed to perform heterogeneous catalysis.