The interest in polynuclear cobalt clusters is motivated by the fact that some of them exhibit the single-molecule magnets phenomenon [1]. Recently we have reported a series of heteronuclear {MnII2CoII2MnIII2} and {CoII4FeIII2} clusters starting from [Co(ib)2] (where: ib = isobutyric acid) and aminoalcohols. [2]. In this research we were interested in the influence of the pure cobalt ions on the magnetic properties of the final material. For this reason [Co(ib)2] was reacted with aminoalcohols (in this case with bda = N-butyldiethanolamine) giving rise to the pentanuclear mixed-valence cluster [CoII3CoIII2(ib)6(Hbda)2(bda)2]-1.5MeCN. The molecular structure of the cluster consists of five distorted octahedral cobalt ions arranged in a half-ring fashion bridged by four bda ligands (two fully deprotonated and two monodeprotonated, which form short hydrogen bonds of 2.526 and 2.536 Å to the monodentate ib groups) and four ib ligands. Two additional monodentate deprotonated ib ligands (as evident from short C=O distances of 1.235 and 1.268 Å) coordinate to the peripheral cobalt atoms (Figure). Analyzing the Co-N and Co-O bond distances reveals that the central and peripheral cobalt atoms are in the oxidation state +2, while the remaining two atoms are in the oxidation state +3.   Magnetic data of {Co5} cluster are in accordance with three high-spin Co(II) and two low-spin Co(III) centers. The latter induce a small temperature independent paramagnetic contribution to the magnetic susceptibility, therefore almost isolating the Co(II) centers. The data are analyzed using the computational framework CONDON 2.0. They show three high-spin Co(II) centers in a distorted octahedral ligand field, which are in good approximation isolated. The Heisenberg parameter reveals very weak antiferromagnetic exchange interactions (-2J = 0.08 cm^-1).