The synthesis and characterization of rhenium nitrosyl complexes. The X-ray crystal structures of [ReBr2(NO)(NCMe)3], [Re(NO)(N5)] (BPh4)2] and [ReBr2(NO)(NCMe) {py-CH2-NH∼CH2CH2-N(CH2-py)2}]

Reactions of low oxidation state rhenium-nitrosyl complexes with polyamine ligands have been examined. Rhenium(II)-nitrosyl complexes gave an array of unstable products that were difficult to isolate cleanly. The rhenium(l)-nitrosyl complex [ReBr2(NO)(NCMe)(3)] gave multiple products which were more easily isolated. The major product from the reaction of [ReBr2(NO)(NCMe)(3)] with the potentially pentadentate ligand N-1,N-1,N-2-tris(2-pyridinylmethyl)-1,2 ethanediamine was the dicationic species [Re(NO)(N5)](2+), which was isolated as the bis-tetraphenylborate salt. The other major product [ReBr2(NO)(NCMe) (py-CH2NH similar to CH2CH2N(CH2-py)(2)}], was separated from a number of other neutral species via chromatography. This species contains the same potentially pentadentate ligand, only here it is coordinated through only two of its amine functional groups. Left dangling is the secondary amine and both of its pyridyl groups. Both amine complexes are diamagnetic and both display their respective parent ions in the ESI(+) mass spectra. The dication [Re(NO)(N-5)](2+) shows its half mass parent peak at 275 m/z while [ReBr2(NO)(NCMe)[py-CH2NH similar to CH2CH2N(CH2-py)(2)}] shows its parent peak at 751 m/z. The infrared spectrum of [ReBr2(NO)(NCMe)[py-CH2NH similar to CH2CH2N(CH2-py)(2)}] displays its v(N=O) at 1676 cm(-1). And the infrared spectrum of [Re(NO)(N5)](BPh4)(2) displays its v(N=O) at 1714 cm(-1). (C) 2013 Elsevier B.V. All rights reserved.