Synthesis, crystal, molecular and electronic structure of rhenium nitrosyl with pyrazole in the coordination sphere

The reaction of [ReBr3(NO)(PPh3)2] complex with pyrazole (pzH) has been examined and a new rhenium nitrosyl – [ReBr3(NO)(PPh3)(pzH)] – has been obtained. The X-ray structure of the [ReBr3(NO)(PPh3)(pzH)] complex has been determined and its electronic structure has been calculated with the density functional theory (DFT) method with the use of B3LYP functional. Additional information about binding in the [ReBr3(NO)(PPh3)(pzH)] complex has been obtained by NBO analysis. The time-dependent DFT method (TDDFT) has been used for calculations of spin-allowed doublet–doublet electronic transitions of [ReBr3(NO)(PPh3)(pzH)], and on this basis the UV–Vis spectrum has been discussed.