An experimental and computational study of 1,1′-ferrocene diamines

A Redox‐Switchable Germylene and its Ligating Properties in Selected Transition Metal Complexes

“…Although the THF/[ n Bu 4 N][Al{OC(CF 3 ) 3 } 4 ] electrolyte was stored over sodium and thoroughly dried glassware was used in a special setup for inert conditions developed by Heinze, 4 is rapidly hydrolyzed by trace amounts of water to the parent amine 2 (Figure ). The latter shows a quasi‐reversible redox process centered at E 0 1/2 =−0.69 V (vs. the ferrocene/ferrocenium couple, Fc/Fc + ), which perfectly fits to studies reported previously by Diaconescu and Siemeling . The quasi‐reversible oxidation of 4 detected at E 0 1/2 ≅0.15 V is slightly more anodically shifted compared to the value reported by Siemeling and co‐workers ( E 0 1/2 =−0.055 V), which may be attributed to differences in the experimental conditions or artefacts resulting from the relatively large Δ E p value of approximately 400 mV observed in our case.…”

“…Compound 4 is a (very) moisture and air‐sensitive red solid that is thermally stable (m.p.=235–237 °C). The UV/Vis spectrum of 4 in THF shows broad bands around λ =456 ( ϵ =962 dm −3 mol −1 cm −1 ) and 294 nm ( ϵ =16 360 dm −3 mol −1 cm −1 ), which correspond to ferrocene‐based d – d transitions and fall in the typical range found for 1,1′‐ferrocene diamines …”

Redox‐Active N‐Heterocyclic Germylenes and Stannylenes with a Ferrocene‐1,1′‐diyl Backbone

“…As reported previously, the corresponding amine precursors 1 R H 2 are all oxidised in a chemically reversible one‐electron oxidation process at very negative potentials. Differences between the E 1/2 values mildly reflect the various degrees of electron donation by the amino substituents, that is, −0.730, −0.680, and −0.630 V for R=Np, Mes, and TMS, respectively.…”

“…Therefore, we chose this particular alkyl substituent for the present study, with mesityl and trimethylsilyl, two popular bulky non‐alkyl substituents, which have also been utilised successfully to obtain stable monomeric N‐heterocyclic germylenes and stannylenes . Diaminoferrocene derivatives of the type [fc(NHR) 2 ] ( 1 R H 2 ; R=Np, Mes, and TMS) are easily accessible starting materials for our purposes. We note that a decade ago Wrackmeyer et al.…”

Rare Earth Arene-Bridged Complexes Obtained by Reduction of Organometallic Precursors

“…Our group previously synthesized group 3 metal monoalkyl complexes supported by ferrocene diamide ligands (Chart 8) (Diaconescu, 2010a;Diaconescu, 2010b) and studied their reactivity toward various organic substrates, including aromatic N-heterocycles (Carver and 16 Diaconescu, 2008;Miller et al, 2009) and other unsaturated substrates ). The 1,1′-ferrocenediyl (fc) diamide ligands have the general formula fc(NR)2; the system studied the most by us has R = Si t BuMe2 , while other versions, such as R = SiMe3 (Monreal et al, 2007), SiPhMe2 (Duhović and Diaconescu, 2013), adamantyl (Wong et al, 2010), 2,4,6-trimethylphenyl, and3,5-dimethylphenyl (Lee et al, 2011) have been explored only briefly. Group 3 metal alkyl complexes supported by a pincer-type pyridine diamide ligand, 2,6-bis(2,6-di-iso-propylanilidomethyl)pyridine (N2N py ) (Guerin et al, 1995), were also synthesized for a reactivity comparison study (Chart 8) (Jie and Diaconescu, 2010).…”