Abstract A number of mono-and di-phosphaterrocenes have been synthesised and their NMR (1 H, 31 P) and Mössbauer spectra measured. The presence of a phosphorus atom in the cyclopentadienyl (Cp) moiety causes a reduction of about 0.3 mm s− 1 in the quadrupole splitting (QS) compared with what of ferrocene. The effect appears to be additive, as does the effect of Cp ring substituents. Thus 2, 5-diphenylphosphaferrocene (I), 3, 3′, 4, 4′- ...
[Mathey, Francois; Mercier, Francois; Charrier, Claude; Fischer, Jean; Mitschler, Andre Journal of the American Chemical Society, 1981 , vol. 103, # 15 p. 4595 - 4597]