Synthesis, structure, and reactivity of (η5:η1-C5Me4(CH2)2NMe2)Re(CO)2. Electron transfer behavior of a nitrosyl derivative

• The dimethylamino group is easily displaced by two electron donor ligands.
• Re(III) complexes exhibited a trans stereochemistry, the NMe2 remained coordinated.
• The assignment of the NO stretching band was confirmed by 15N enriched compound.
• The new {ReNO}6 was prepared and characterized and the redox behavior was studied.

The UV irradiation of a hexane solution of the complex (η5-C5Me4(CH2)2NMe2)Re(CO)3 (1) afforded the chelated species (η5:η1-C5Me4(CH2)2NMe2)Re(CO)2 (2). The molecular structure of 2 has been determined by X-ray crystallography. The reaction of 2 with two-electron donor ligands yields (η5-C5Me4(CH2)2NMe2)Re(CO)2(L) (1, L = CO; 3, L = PMe3). The chelated species 2 also reacts with MeOTf, HBF4, and I2 to form the cationic compounds trans-[(η5-C5Me4(CH2)2NMe2)Re(CO)2X]+ ([4]+, X = Me; [5]+, X = H; [6]+, X = I). The trans stereochemistry of 4–6 have been assigned on the basis of ν(CO) IR intensities and 13C NMR spectroscopy. Also, complex 2 reacts with nitrosyl tetrafluoroborate to yield [(η5-C5Me4(CH2)2NMe2NO)Re(CO)2(NO)]BF4 ([7]2+). The redox behavior of the {ReNO}6 complex [7]2+ was studied and the products obtained after two-electron reduction were characterized by IR. DFT calculations were done to optimize the structure of [7]2+ and to study the effect of the sidearm coordination on the electronic structure of a cyclopentadienyl {ReNO}8 complex.

The NMe2 group in the complex (η5:-2 (2) is easily displaced by two electron donor. However, the cationic species Re(III) with a trans stereochemistry, in which the NMe2 sidearm remained coordinated. The redox behaviour of the nitrosyl derivative was studied and the DFT calculations were done to optimize the structure.Figure optionsDownload as PowerPoint slide