A range of new manganese complexes featuring nitrogen coordination and mixed oxygen-/nitrogen coordination have been successfully synthesized and comprehensively characterized. Intriguingly, within the set of all-nitrogen coordinated compounds, only the Bis(N,N´-ditertbutylacetamidinato)manganese(II) (II), demonstrated a mononuclear configuration in the solid state, while the rest exhibited a dinuclear structure. Notably, despite this trend, the thermal characteristics of another compound, namely the Bis(N,N´-ditertbutylformamidinato)manganese(II) (IV), displayed enhanced thermal stability relative to II, suggesting a mononuclear transition in the gaseous phase. In contrast to II, compound IV exhibited constant evaporation behavior in isothermal thermogravimetry experiments. From DFT based reactivity investigations towards molecular oxygen, compound (IV) showed favorable interaction with O2. For the manganese ßketoiminates, an interesting structural trend could be observed. With the sterically demanding side chains like isopropyl and tertbutyl (compounds ßIII and ßIV) mononuclear compounds were formed, while with the employment of smaller side chains, dinuclear structures were obtained. Among all the compounds, the Bis(4-(isopropylamino)pent-3-en-2-onato)manganese(II) (ßIII) reveals the most promising physico-chemical properties which are relevant for ALD and CVD processes. In contrast to the all-nitrogen coordinated compound, this compound revealed unfavorable interaction with oxygen in DFT interaction studies. These observations led to reactivity studies of (ßIII) towards H2O which demonstrated favorable interaction with water as a suitable co-reactant. The combination of experimental investigations on precursor characteristics in combination with DFT studies gave a deep insight into the influence of ligand variation, the systematic changes on the ligand backbone and side chain variation on the chemico-physical properties of the new manganese compounds. Based on the physico-chemical properties of the compounds obtained, coupled with the theoretical DFT studies, the Mn ketoiminates seem highly promising for CVD and ALD of Mnbased materials, which we will pursue in our follow up study.