The reactivity of [ReBr3(MeCN)(dppe)] towards gaseous nitric oxide. The X-ray structure of [ReBr3(MeCN)(dppe)] and [ReBr3(NO)(dppe)]0.57[ReOBr3(dppe)]0.43 and DFT calculations for [ReBr3(NO)(dppe)] and [ReOBr3(dppe)]

The [ReOBr3(dppe)] (dppe=bis(diphenylophosphino)ethane) complex reacts with acetonitrile in the presence of excess of triphenylphpsphine to give a new monomeric nitrile rhenium(III) complex-[ReBr3(MeCN)(dppe)] (1). The reaction of 1 with gaseous nitric oxide leads to the mixed [ReBr3(NO)(dppe)]0.57[ReOBr3(dppe)]0.43 complex (2) with rhenium atoms on +2 and +5 oxidation states. This paper presents the synthesis, spectroscopic characterisation and X-ray structure of 1 and 2. The geometries of [ReBr3(NO)(dppe)] and [ReOBr3(dppe)] have been optimized using the density functional theory (DFT) and the electronic transitions of [ReBr3(NO)(dppe)] and [ReOBr3(dppe)] have been calculated with the time-dependent DFT method (TDDFT). The UV-vis spectrum of 2 has been interpreted on the basis of the experimental data for [ReOBr3(dppe)] and the calculated transitions for [ReOBr3(dppe)] and [Re(NO)Br3(dppe)].