Reaction of piperazine with isothiocyanate (iPrO)2P(S)NCS leads to N-thiophosphorylated bis-thiourea (iPrO)2P(S)NHC(S)NC 4H8NC(S)NHP(S)(OiPr)2 (H2L). Recrystallization of H2L from DMSO leads to the formation of the new ligand (iPrO)2P(S)NC4H8NP(S)(OiPr)2 (1). Reaction of doubly deprotonated L with CoII leads to the [Co2L2] complex. The thermal properties of [Co 2L2] in an air atmosphere were studied by means of TGA with the observed final residue corresponding to [CoPS3]2. The crystal structure of [Co2L2] was elucidated by single crystal X-ray diffraction. Two metal cations are in a tetrahedral 1,5-S 2S′2 environment formed by the CS and PS sulfur atoms. Investigation of the temperature dependence of the magnetic susceptibility is consistent with two effectively non-interacting Co II S = 3/2 ions.