1,1′-Bis(phosphoranylidenamino)ferrocene palladium(II) complexes: An unusual case of dative Fe→Pd bonding

Evaluation of heterocumulenic ferrocene derivatives for “click” chemistry type reactions

“…We have therefore briefly investigated the reaction of 1 and 2 with fc(PPh 2 ) 2 (dppf), which mimics two adjacent reactive sites in a SAM which contains terminal phosphanyl groups. Related reactions of 2 with monophosphanes PR 3 (R = Ph, Cy) were reported by Metallinos et al to afford the respective bis(iminophosphorane) fc(N = PR 3 ) 2 in moderate isolated yields [24], while Otón et al described an almost quantitative yield of crude product in the reaction of 2 with PPh 3 [25]. We performed the reaction of 1 (2 equiv.)…”

Transition‐Metal Complexes with Ferrocene‐Bridged Bis(imidazolin‐2‐imine) and Bis(diaminocyclopropenimine) Ligands

“…[5i] As noted in the introduction, some ferrocene-containing ligands may form Fe-Pd bonds in Pd II complexes. [11][12][13][14][15] Characteristics of such complexes are a very large separation of ferrocene H α and H 1 H NMR signals (Δδ up to 2.1 ppm), short Fe-Pd distances (as short as 2.63 Å) and, as determined by Mössbauer spectroscopy, smaller values for the quadrupole splitting in the complex than in the free ligand.…”

“…[1c,1d] Additionally, ferrocene ligands may be capable of forming Fe-M bonds towards a chelated metal atom, resulting in a κ 3 coordination mode. Ferrocene complexes, such as ferrocene dithiolates [11] or dithio- ethers, [12] diphosphanes [13] bis(iminophosphoranes) [14] or bisguanidines, [15] readily form Fe-Pd bonds in Pd II complexes. In this study, we wish to report the synthesis and characterization of various complexes of metal chloride salts with the electron-rich ferrocene-bridged bis(imidazolin-2-imine) ligand fc(NIm) 2 (1; Figure 1).…”

Beyond Common Metal–Metal Bonds, κ3‐Bis(donor)ferrocenyl→Transition‐Metal Interactions

“…The iminophosphoraneferrocene ligands [Fe(C 5 H 4 NPCy 3 ) 2 ], (Cy‐=cyclohexyl) and [Fe(C 5 H 4 NPPh 3 ) 2 ] show different reactivity when bound to PdCl 2 . The palladium complex [PdCl 2 (Fe(C 5 H 4 NPPh 3 ) 2 ))] ([ 9 Cl 2 ]) was in equilibrium with [ 9 Cl]Cl (Scheme ) containing a proposed Fe→Pd bond based on the UV/Vis and 1 H NMR analysis . The chloride was removed by salt metathesis with NaB(Ar F ) 4 and the molecular structure of [ 9Cl ]B(Ar F ) 4 showed a Fe→Pd bond (d Fe−Pd =2.674/ α 18°) .…”

“…The palladium complex [PdCl 2 (Fe(C 5 H 4 NPPh 3 ) 2 ))] ([ 9 Cl 2 ]) was in equilibrium with [ 9 Cl]Cl (Scheme ) containing a proposed Fe→Pd bond based on the UV/Vis and 1 H NMR analysis . The chloride was removed by salt metathesis with NaB(Ar F ) 4 and the molecular structure of [ 9Cl ]B(Ar F ) 4 showed a Fe→Pd bond (d Fe−Pd =2.674/ α 18°) . In contrast, [PdCl 2 (Fe(C 5 H 4 NPCy 3 ) 2 )] ([ 10 Cl 2 ]) did not show similar behavior and [ 10 Cl 2 ] did not react with NaB(Ar F ) 4 .…”