Well-defined iron bis(diphosphine) complexes are active catalysts for the dehydrogenative C–H borylation of aromatic and heteroaromatic derivatives with pinacolborane. The corresponding borylated compounds were isolated in moderate to good yields (25–73%) a 5 mol% catalyst loading under UV irradiation (350 nm) at room temperature. Stoichiometric reactivity studies isolation an original trans-hydrido(boryl)iron complex, Fe(H)(Bpin)(dmpe)2, allowed us propose mechanism showing role some key...

We report herein the use of (dihydrido)iron catalyst, Fe(H)2(dmpe)2, for selective reduction CO2 into either bis(boryl)acetal or methoxyborane depending on hydroborane used as a reductant. In one-pot two-step procedure, in situ generated was shown to be reactive and versatile source methylene create new C-N but also C-O C-C bonds.

Abstract First‐row two‐coordinate complexes are attracting much interest. Herein, we report the high‐yield isolation of linear iron(I) complex salt [K(L)][Fe{N(SiMe 3 ) 2 } ] (L=18‐crown‐6 or crypt‐222) through reduction either [Fe{N(SiMe its three‐coordinate phosphine adduct (PCy )]. Detailed characterization is gained X‐ray diffraction, variable‐temperature NMR spectroscopy, and magnetic susceptibility studies. One‐ two‐electron oxidation reaction with I further found to afford...

Anionic two-coordinate complexes of first-row transition-metal(I) centres are rare molecules that expected to reveal new magnetic properties and reactivity. Recently, we demonstrated a N(SiMe3)2(-) ligand set, which is unable prevent dimerisation or extraneous coordination at the +2 oxidation state iron, was nonetheless able stabilise anionic Fe(I) even in presence Lewis base. We now report analogous Cr(I) Co(I) with exclusively this amido isolation [Mn(I){N(SiMe3)2}2]2(2-) dimer features...

Abstract The 3d‐metal mediated nitrene transfer is under intense scrutiny due to its potential as an atom economic and ecologically benign way for the directed amination of (un)functionalised C−H bonds. Here we present isolation characterisation a rare, trigonal imido cobalt(III) complex, which bears rather long cobalt–imido bond. It can cleanly cleave strong bonds with bond dissociation energy up 92 kcal mol −1 in intermolecular fashion, unprecedented cobalt complexes. This resulted amido...

Imidyl and nitrene metal species play an important role in the N-functionalisation of unreactive C-H bonds as well aziridination olefines. We report on synthesis trigonal imido iron complexes [Fe(NMes)L2]0,- (L = -N{Dipp}SiMe3); Dipp 2,6-diisopropyl-phenyl; Mes (2,4,6-trimethylphenyl) via reaction mesityl azide (MesN3) with linear precursors [FeL2]0,-. UV-vis-, EPR-, 57Fe Mössbauer spectroscopy, magnetometry, computational methods suggest for reduced form electronic structure a...

The rational design of 3d-metal-based single-molecule magnets (SMM) requires a fundamental understanding their intrinsic electronic and structural properties how they translate into experimentally observable features. Here, we determined the magnetic linear iron(I) silylamides K{crypt}[FeL2] [KFeL2] (L = −N(Dipp)SiMe3; crypt 4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo[8.8.8]hexacosan). For former, slow-relaxation magnetization with spin reversal barrier Ueff 152 cm–1 as well closed-waist...

This report describes a series of rare low-coordinate 3d transition metal alkyne complexes resulting from the reaction quasi-linear metal(I) silylamides, K{18c6}[MX2] (18c6 = 18-crown-6; X -N(SiMe3)2), -N(Dipp)SiMe3; Dipp 2,6-diisopropylphenyl), chromium, manganese, iron, and cobalt with aliphatic aromatic alkynes. We evaluated interaction alkynes in dependence substituents. Whereas only weak reversible coordination is observed for cobalt, formation side-on type [M(L2)(η2-RCCR)]- takes place...

We report on the synthesis of a variety trigonal imido cobalt complexes [Co(NAryl)L2 ]- , (L=N(Dipp)SiMe3 ), Dipp=2,6-diisopropylphenyl) with very long Co-NAryl bonds around 1.75 Å. Their electronic structure was interrogated using physical and spectroscopic methods such as EPR or X-Ray absorption spectroscopy which leads to their description highly unusual imidyl complexes. Computational analyses corroborate these findings further reveal that high-spin state is responsible for character....

Chelating phosphines are widely used as robust and reliable ligands in catalysis. We show that the anionic iron(i) complex [FeI(N(SiMe3)2)2]- is able to selectively cleave a P-aryl bond of 1,2-bis(diphenylphosphino)benzene. Furthermore, related cis-1,2-bis(diphenylphosphino)-ethylene (dppee) binds not P donors but ethylene unit, (catalytically) transformed trans-isomer.

The synthesis of quasilinear metal(<sc>i</sc>) silylamides [KM(N(Dipp)SiR₃)₂] chromium to cobalt, their diverse speciation in solid state and solution as well reactivity towards alkynes are reported.

Abstract First‐row two‐coordinate complexes are attracting much interest. Herein, we report the high‐yield isolation of linear iron(I) complex salt [K(L)][Fe{N(SiMe 3 ) 2 } ] (L=18‐crown‐6 or crypt‐222) through reduction either [Fe{N(SiMe its three‐coordinate phosphine adduct (PCy )]. Detailed characterization is gained X‐ray diffraction, variable‐temperature NMR spectroscopy, and magnetic susceptibility studies. One‐ two‐electron oxidation reaction with I further found to afford...

Herein, we disclose the facile reduction of pyridine (and its derivatives) by linear 3d-metal(I) silylamides (M=Cr-Co). This reaction resulted in intermolecular C-C coupling to give dinuclear metal(II) complexes bearing a bridging 4,4'-dihydrobipyridyl ligand. For iron, demonstrated that is reversible solution, either directly or with substrates, via presumed monomeric complex pyridyl radical anion. In course this investigation, also observed incorporating iron facilitated isomerisation...

Quasi-linear anionic 3d-metal(I) silylamides are a new and promising class of molecules. Due to their highly negative reduction potential we wanted test capability reduce substrates under coordination monoanionic radicaloid form. In proof principle study, present the results reaction metal(I) chromium cobalt with 2,2′-bipyridine (bipy), redox non-innocence reducibility which was already established. course these studies complexes type K{18-crown-6}[M(hmds)2(bipy)] (hmds = –N(SiMe3)2) were...

A family of four-coordinate FeII complexes formed with N,N'-chelating amido-pyridine ligands was synthesized, and their magnetic properties were investigated. These distorted tetrahedral exhibit significant anisotropy zero-field splitting parameter D ranging between -17 -12 cm-1. Ab initio calculations enabled identification the structural factors that control nature rationalization variation in these complexes. It is shown a reduced N-Fe-N angle involving chelating nitrogen atoms at origin...

Iron(i) species are debated as key intermediates during the C-halide activation step in Kumuda type C-C cross-coupling catalysis. However, there is only limited knowledge on reactivity of isolable iron(i) complexes towards organohalides. Using known two-coordinate complex K{18c6}[FeI(N(SiMe3)2)2] we disclose its proficiency to rapidly cleave different types carbon halide bonds including even C-F bonds. Mechanistic studies indicate stepwise one-electron processes with involvement organoradicals.

Abstract Der 3d‐Metall‐vermittelte Nitrentransfer ist Gegenstand intensiver Forschung aufgrund seines Potentials als atomökonomischer und umweltfreundlicher Ansatz zur direkten Aminierung (un)funktionalisierter C‐H‐Bindungen. Wir berichten nun über die Isolierung Charakterisierung eines selten trigonalen Imidocobalt(III)‐Komplexes mit einer sehr langen Cobalt‐Imid‐Bindung. Er kann auf intermolekularer Weise, präzedenzlos für Imidocobaltkomplexe, starke C‐H‐Bindungen...

Carbonyl and iminyl based radical anions are reactive intermediates in a variety of transformations organic synthesis. Herein, the isolation ketyl, more importantly unprecedented ketiminyl aldiminyl coordinated to cobalt iron complexes is presented. Insights into electronic structure these unusual metal bound provided by X-Ray diffraction analysis, NMR, IR, UV/Vis Mössbauer spectroscopy, solid solution state magnetometry, as well detailed computational analysis. The very facilitate...

By employing the 2,2'-thiobis(2,4-di-tert-butylphenolate) ligand ((S)L(2-)) a novel oxovanadium(V) complex, (PPh(4))(2)[(S)LV(O)(μ(2)-O)(2)V(O)(S)L] (1), was synthesised that exhibits haloperoxidase activity: on addition of H(2)O(2) sequence successive peroxide formation and intramolecular thioether oxidation events (sulfoxide sulfone) led to mixture five products, which were all identified unambiguously, partly through an independent synthesis characterisation. It shown internal proceeds...

Syntheses and magnetic behavior of bis(trimethylsilyl)amido tricyclopentylphosphane complexes [M{N(SiMe 3 ) 2 } (PCyp )] manganese(II), iron(II), cobalt(II) are described. Crystal structures for this series rare phosphane adducts homoleptic bis(trimethylsilyl)amide have been solved. The Fe Co derivatives found to possess large anisotropy, with zero‐field splitting (ZFS) parameters, D , –38 –57 cm –1 respectively. Both compounds exhibit slow relaxation their magnetization in an applied field.

Abstract A [Fe‐S‐Fe] subunit with a single sulfide bridging two low‐coordinate iron ions is the supposed active site of iron‐molybdenum co‐factor (FeMoco) nitrogenase. Here we report dinuclear monosulfido bridged diiron(II) complex similar geometry that can be oxidized stepwise to diiron(II/III) and diiron(III/III) complexes while retaining core. The series has been characterized crystallographically, electronic structures have studied using, inter alia, 57 Fe Mössbauer spectroscopy SQUID...

Abstract A series of halido bis(silylamido) metalates chromium to cobalt is reported. Reaction [NBu 4 ]Br with linear metal silylamides ML 2 (M=Mn−Co, L=−N(SiMe 3 ) , −N(Dipp)SiMe ; Dipp=2,6‐ i Pr−C 6 H leads NBu [M(Br)L ] whereas for either intramolecular deprotonation (L=−N(SiMe or ligand exchange (L=−N(Dipp)SiMe observed. Attempts their reduction KC 8 showed in part the formation metal(I) silylamide complexes but also degradation. In contrast, analogous compounds bearing a [K{18c6}] +...

Abstract The synthesis of a T‐shaped imido nickel complex is reported, obtained by the reaction phenyl azide with linear nickel(I) silylamide K{18‐crown‐6}[NiL 2 ] (L=−N(Dipp)SiMe 3 ; Dipp=2,6‐di iso propylphenyl). In addition, an unusual shift SiMe unit from ancillary ligand to putative [Ni=NPh] observed. Examination resulting [Ni=NDipp] for its electronic properties leads description as low‐spin nickel(III) imide and revealed only limited activity respect H‐atom abstraction C−H bonds or...

In this report, we present intricate pathways for the synthesis of linear nickel(I) silylamide K{m}[Ni(NR2)2] (NR2 = -N(SiMe3)2). This is achieved first via reduction nickel(II) trisamide Li(donor)4[Ni(NR2)3] (Li(thf)x[1]) with KC8 in presence 18-crown-6 or crypt.222. due course, behavior as a source masked two-coordinate hexamethyldisilazanide explored, leading to formation and N-donor adducts, well metal-metal-bonded dinickel(I) K(toluene)[Ni2(NR2)3] (K(toluene)[5]). Finally, convenient...