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

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.