The coordination capabilities of the pyrazolyl containing ligands pz*(CH2) 2NH (CH2) 2pz*, pz*(CH2) 2NH (CH2) 2NH2, pz*(CH2) 2S (CH2) 2pz* and pz*(CH2) 2S (CH2) 2NH2 (pz*= 3, 5-Me2pz) towards the synthon (NEt4) 2 [ReBr3 (CO) 3](1) were studied. Depending on the reaction conditions, neutral or cationic Re (I) tricarbonyl complexes have been isolated:[ReBr (CO) 3 (κ2-pz*(CH2) 2NH (CH2) 2pz*)](2),[ReBr (CO) 3 (κ2-pz*(CH2) 2S ( ...