Syntheses and reactivity studies of solvated dirhenium acetonitrile complexes

Fully and partially solvated triply-bonded Re2]4+ complexes have been synthesized and their X-ray structures are described. A fully solvated dirhenium salt with BArf tetrakis(3,5-bis(trifluoromethyl)phenyl)borate] as the counter anion Re2(CH3CN)10]BArf]4 () has been characterized. The solubility of the complex in CH2Cl2 and THF in addition to CH3CN offers the possibility of improved reactivity. The structure of Re2(micro-O)(CH3CN)10]BF4]4 () that possesses a linear Re(III)-O-Re(III)]4+ unit is reported. Protonation reactions of cis-Re2Cl2(dppm)2(O2CCH3)2 and trans-Re2Cl4(dppm)2 with HBF4.Et2O in acetonitrile afforded cis and trans Re2(dppm)2(CH3CN)6]BF4]4 ( and ), respectively. Prolonging the reaction time, however, does not lead to fully solvated complex Re2(CH3CN)10]BF4]4. The neutral nitrogen donor ligands pynp (2-(2-pyridyl)-1,8-naphthyridine) and tznp (2-(2-thiazolyl)-1,8-naphthyridine) react readily with Re2(CH3CN)10]BF4]4 to provide trans-Re2(pynp)2(CH3CN)4]BF4]4 and trans-Re2(tznp)2(CH3CN)4]BF4]4. The X-ray structures trans-Re2(pynp)2(CH3CN)4]BF4]4 () and trans-Re2(tznp)2(CH3CN)4]BF4]3PF6] () have been determined.