Retta, Negussie (Professor)Bogale, Yiheyis2018-06-272023-11-092018-06-272023-11-092008-07http://etd.aau.edu.et/handle/12345678/3797A hydrated mononuclear complex [Co(H2O)2L].4H2O, where L is N,N’- bis(salicylidene)-3’,4’-diamino-2,2’:5’,2’’-terthiophene, has been synthesized and characterized by elemental analysis, molar conductance, magnetic moment and spectral data (FTIR, AA and UV-Vis spectroscopy). Cobalt(II) ion coordinates with four donor atoms of the ligand and two water molecules. The ligand behaves as a dibasic tetradentate ONNO donor by involving oxygen’s of the deprotonated phenol groups and Nitrogen’s of the imine functions. Electronic spectra and room temperature effective magnetic moment of the complex reveal a high-spin octahedral geometry in solid state. Key words: mononuclear, N, N’-bis (salicylidene)-3’, 4’-diamino-2, 2’:5’, 2’’-terthiophene, Cobalt(II), dibasic tetradentate, imine, high-spin octahedral geometryenMononuclearN, N’-bis (salicylidene)-3’, 4’-diamino-2, 2’:5’, 2’’-terthiopheneCobalt(II)Dibasic tetradentateImineHigh-spin octahedral geometryThesis