420796-88-9Relevant academic research and scientific papers
[(η5-C5Me5)Fe(Ph2PCH 2 CH2CH2PPh2)][SO3CF3 ] (see abstract)
Argouarch, Gilles,Hamon, Paul,Toupet, Lo?c,Hamon, Jean-René,Lapinte, Claude
, p. 1341 - 1348 (2008/10/08)
The iron chloro complex Cp*(dppp)FeCl (Cp* = pentamethylcyclopentadienyl, dppp = 1,3-bis(diphenylphosphino)propane; 2) was prepared from FeCl2(dppp) and Cp*Li in 85% yield. The air-stable compound 2 was characterized by IR-FT, 1H, 31P, and 13C NMR, cyclic voltammetry (CV), and X-ray crystal analysis. The experimental data indicate that this complex possesses the same electronic properties as its homologue Cp*(dppe)FeCl (dppe = 1,2-bis(diphenylphosphino)ethane; 2′), but shorter distances between the chlorine atom and the hydrogen atoms of the dppp ligand give rise to through-space interactions. The hydride 3 was obtained by treatment of the chloro derivative 2 with LiAlH4 (95%). The changes in the Fe-H bond stretching and redox potential induced by replacement of dppe by dppp is in agreement with the existence of two conformers for the iron hydrides 3 and 3′. The 16-electron species [Cp*(dppp)Fe][OSO2CF3] (4[OTf]) is obtained by treatment of 3 with methyl triflate in diethyl ether (82%). The pseudo-C2v conformation of 4[OTf] is established by an X-ray analysis. Complex 4[OTf] possesses a triplet ground state, as shown by the magnetic susceptibility measurements, 1H NMR, and M?ssbauer spectroscopy. The UV-vis data obtained for 4[OTf] and its homologue 4′[PF6] suggest that the increase of the bite angle of the bis-phosphine should produce a decrease of the HOMO-LUMO gap of the triplet ground state with a pseudo-C2v symmetry.
