Electrochemistry of di-tert-butylphosphinopentaphenylferrocene (Q-phos) and derivatives

Activation of H2 by frustrated Lewis pairs derived from mono- and bis-phosphinoferrocenes and B(C6F5)3

“…The 31 P NMR spectrum of 7 comprises a doublet at 49.0 ppm with a P-H coupling constant of 446 Hz, while the 11 B NMR signal is a doublet at À25.4 ppm with B-H coupling of 90 Hz. These data, together with the 1 H, 19 F and 13 C{ 1 H} NMR data, are consistent with the formulation of 7 as [(Z 5 -C 5 Ph 5 )Fe(Z 5 -C 5 H 4 PHtBu 2 )][HB(C 6 F 5 ) 3 ]. This was subsequently confirmed by X-ray crystallography (Fig.…”

“…18 The growth of a reversible wave at 0.12 V was attributable to the presence of parent phosphine, [(Z 5 -C 5 Ph 5 )Fe(Z 5 -C 5 H 4 PtBu 2 )]. 19 Collectively, these data demonstrate the unique reactivity of bulky phosphinoferrocenes with B(C 6 F 5 ) 3 . Steric demands about P preclude reaction with B(C 6 F 5 ) 3 to give simple Lewis acid-base adducts.…”

“…These data support the formation of phosphonium and borate centers. The 19 F NMR spectrum shows signals at À117.8 and À130.1 ppm attributable to a C 6 F 4 fragment in addition to resonances attributable to C 6 F 5 and BF units. These data support the formulation of 1 as [(Z 5 -C 5 H 5 )Fe(Z 5 -C 5 H 4 PtBu 2 (C 6 F 4 )BF(C 6 F 5 ) 2 )] (Scheme 1), in which the phosphinoferrocene has effected attack at the para-carbon of a C 6 F 5 ring, prompting fluoride transfer to B.…”

Study of ferrocene derivatives Fe(C5H4X)(C5H5−n Y n ) by cyclic voltammetry and matrix-activated laser desorption/ionization time-of-flight mass spectrometry

“…The val ue determined by us for the redox potential is 41 mV rela tively to ferrocene and agrees with the published data. 26 A comparison of the redox potentials of compounds 6 and 9 suggests that the introduction of phenyl substituents into …”