As a result of the Doctoral Thesis, new Eu3+ organic tris, Lewis base, and tetrakis complexes with different β,β’-triketonates and β-diketonates (derivatives of 2-acyldimedone, 2-acyl-1,3-indandione and dibenzoylmethane) were obtained and their emission properties in solvents, powder state, and polymer films were investigated and compared. Impact of complex structure and cation size of tetrakis complexes on emission properties were investigated. Two OLEDs with Eu3+ β-diketonate complex were fabricated. For the first time, aggregation enhanced emission was present for Eu3+ complexes with derivatives of dibenzoylmethane ligands. Also series of derivatives of 2-cinnamoyldimedone and 2-cinnamoyl-1,3-indandione were synthesized and their optical, electrochemical and thermal properties were investigated. Ground state geometries and HOMO/LUMO orbitals of all compounds were theoretically calculated using quantum chemistry program “ORCA”. Systematic investigation of different amino donor group and acceptor group impact on properties of obtained compounds were conducted.