Christophe Fliedel

French National Centre for Scientific Research | CNRS · Laboratoire de Chimie de Coordination (LCC), Toulouse

Palladium dichloride (6‐10) and nickel dichloride (11‐15) complexes of a series of N‐substituted/functionalized bis(diphenylphosphino)amine‐type ligands (1‐5) were synthesized and characterized, using multinuclear NMR and FT‐IR, MS and EA. The solid‐state structures of complexes 6, 8·2CHCl3, 12 and 15 could be confirmed by XRD. All the complexes we...

The solution behavior of complex [Rh(COD)(μ-OAc)]2 in the absence and presence of PPN+OAc- in dichloromethane has been investigated in detail by multinuclear NMR spectroscopy. Without additional acetate ions, the compound shows dynamic behavior at room temperature, consistent with an inversion of its C2v structure. Addition of PPN+OAc- reveals an e...

The addition of benzoyl peroxide to [CoII(acac)2] in a 1 : 2 ratio selectively produces [CoIII(acac)2(O2CPh)], a diamagnetic (NMR) mononuclear CoIII complex with an octahedral (X-ray diffraction) coordination geometry. It is the first reported mononuclear CoIII derivative with a chelated monocarboxylate ligand and an entirely O-based coordination s...

Stable latexes containing unimolecular amphiphilic core-shell star-block polymers with a triphenylphosphine(TPP)-functionalized hydrophobic core and an outer hydrophilic shell based on anionic styrenesulfonate monomers have been synthesized in a convergent three-step strategy by reversible addition-fragmentation chain-transfer (RAFT) polymerization...

Rinaldo Poli's significant contribution to coordination chemistry, catalysis and computational chemistry has been benefitting scientific communities for decades. In addition, Rinaldo Poli has been providing valuable support to many chemistry societies and journals. This special collection presents about 30 excellent research articles and reviews in...

Core-crosslinked micelles (CCMs) with a permanently charged anionic shell of sodium poly(styrene sulfonate) (PSS–Na⁺) chains have been developed by a convergent three-step one-pot RAFT polymerization starting with 4-cyano-4-thiothiopropylsulfanyl pentanoic acid (CTPPA, R0-SC(S)SnPr) as chain transfer agent, which includes polymerization-induced sel...

This article highlights the most representative results on the use of coordination compounds in polymerization reactions, since the version of the Comprehensive Coordination Chemistry II by Gibson and Marshall (2003). Noteworthy developments of more efficient catalysts and related significant advancements in coordination polymerization of olefins,...

The present account reviews the most recent noteworthy developments on the synthesis, structure and catalytic applications of Zn‐NHC species, a class of complexes that have attracted attention over the past five to ten years due to their enhanced robustness and hydrolytic stability versus classical Zn organometallics. In particular, thanks to NHC s...

Rhodium nanoparticles (Rh NPs) embedded in different amphiphilic core-crosslinked micelle (CCM) latexes (RhNP@CCM) have been synthesized by [RhCl(COD)(TPP@CCM)] reduction with H2 (TPP@CCM = core-anchored triphenylphosphine). The reduction rate depends on temperature, on the presence of base (NEt3) and on the P/Rh ratio. For CCMs with outer shells m...

Unimolecular amphiphilic nanoreactors with a poly(4‐vinyl‐N‐methylpyridinium iodide) (P4VPMe⁺I⁻) polycationic outer shell and two different architectures (core‐cross‐linked micelles, CCM, and nanogels, NG), with narrow size distributions around 130–150 nm in diameter, were synthesized by RAFT polymerization from an R0‐4VPMe⁺I⁻140‐b‐S50‐SC(S)SPr mac...

This article highlights the role of reversible homolytic metal-carbon bond cleavage processes in organometallic chemistry. Most considerations pertain to thermal bond activation. First, general aspects of the bond cleavage process, including the “persistent radical effect” and the determination/calculation of thermodynamic (bond dissociation enthal...

The novel pentadentate tetrapodal proligand 2,6-bis[(2-hydroxyphenyl)sulfanylmethyl]pyridine (1·H2) and its cobalt(II) complex [Co(1)] (2) were synthesized and characterized by several analytical (EA, ESI-MS) and spectroscopic methods (NMR or EPR, FT-IR), including X-ray crystallography for 1·H2. Cyclic voltammetry studies showed that 2 undergoes a...

The bulk methyl methacrylate (MMA) polymerisation can be achieved with excellent control by ATRP in the presence of FeBr3/EBrPA/Mt+X-, where EBrPA = ethtyl 2-bromophenylacetate and Mt+X- can be one of several inorganic compounds (carbonate, bicarbonate, phosphate, hydroxide, chloride, bromide) of an alkali metal cation. The most effective cations a...

The use of [Mn(RF)(CO)5] (RF = CF3, CHF2, CH2CF3, COCF2CH3) to initiate the radical polymerization of vinylidene fluoride (F2C=CH2, VDF) and the radical alternating copolymerization of vinyl acetate (CH2=CHOOCCH3, VAc) with tert-butyl 2-(trifluoromethyl)acrylate (MAF-TBE) by generating primary RF • radicals is presented. Three different initiating...

Atom Transfer Radical Polymerization (ATRP), a metal‐catalyzed process, is a most powerful method for macromolecular engineering, producing polymers with targeted and low‐dispersity molar masses and with high chain‐end fidelity. This is due to the persistent radical effect, which dramatically reduces the spontaneous radical terminations, prolonging...

Since their early development, N-heterocyclic carbene (NHC) ligands and their related metal complexes have attracted much attention, due to their high performances in many catalytic processes. Structural variations on the heterocycle allowed to fine tune their steric and electronic properties. Introduction of one (or more) additional donor group(s)...

Compound (1‐carbomethoxyethyl)pentacarbonylmanganese(I), [MnR(CO)5] (R = CHMeCOOMe, 1), was synthesized from K⁺[Mn(CO)5]– and methyl 2‐bromopropionate and isolated in pure form. Upon thermal activation, the Mn–R bond is homolytically cleaved and the resulting 1‐carbomethoxyethyl radical is able to initiate the polymerization of methyl acrylate (MA)...

Cyanoisopropyl radicals, generated thermally by the decomposition of azobis(isobutyronitrile) (AIBN), participate in reductive radical termination (RRT) under the combined effect of copper(I) complexes and proton donors (water, methanol, triethylammonium salts) in acetonitrile or benzene. The investigated copper complexes were formed in situ from [...

The title compound, [Mn{SC(O)CF2CH3}(CO)5], has been isolated as a by-product during the reaction of K[Mn(CO)5] with CH3CF2COCl. It is built up from a di­fluoro­methyl­propane­thio­ate bonded to an Mn(CO)5 moiety through the S atom. The Mn atom has an almost perfect octa­hedral coordination sphere. It is one of the rare examples of compounds contai...

Ethyl α-bromophenylacetate (EBrPA) is able to initiate the bulk radical polymerisation of methyl methacrylate (MMA) under thermal conditions (90 °C) in the presence of a variety of simple alkali or alkaline-earth metal or nBu4N salts (Mt+X- with X- = chloride, bromide, iodide, carbonate, bicarbonate, sulfate, bisulfate, nitrate, hydroxide and hexaf...

Thermal decarbonylation of the acyl compounds [Mn(CO)5(CORF)] (RF=CF3, CHF2, CH2CF3, CF2CH3) yielded the corresponding alkyl derivatives [Mn(CO)5(RF)], some of which have not been previously reported. The compounds were fully characterized by analytical and spectroscopic methods and by several single‐crystal X‐ray diffraction studies. The solution‐...

This contribution brings to light the first example of an α-F elimination process in manganese organometallic chemistry. As shown in a recent contribution (Chem. Eur. J., DOI: 10.1002/chem.201804007) the thermal decomposition of compounds [Mn(R F )(CO) 5 ] (R F = CF 3 , 1; CHF 2 , 2; CH 2 CF 3 , 3) in C 6 D 6 at 70-100 °C leads primarily to homolyt...

This article is an account of work, mostly carried out in the authors' laboratory, on the use of organometallic compounds with homolytically fragile metal-carbon bonds as dormant species in the controlled radical polymerization of a variety of monomers in what is now universally called “organometallic-mediated radical polymerization” (OMRP). The ar...

The reaction between [M(acac)3] (M = Fe, Co, acac = acetylacetonate) and the diamino-bis(phenol) pro-ligands (2-OH-3,5-tBu2-C6H2CH2)2NCH2(2-NC5H4) (H21) and (2-OH-5-tBu-C6H3CH2)2NCH2CH2CH2N(CH3)2 (H22) afforded the [κ⁴-(N2,O2)M(acac)] complexes [Fe(1)(acac)] (3), [Fe(2)(acac)] (4), [Co(1)(acac)] (5) and [Co(2)(acac)] (6) in moderate yields after cr...

Discrete two-coordinate Zn(II) organocations are first reported, presently of the type (NHC)Zn-R+, thanks to NHC stabilization. In preliminary reactivity studies, such entities, which are direct cationic analogues of long-known ZnR2 species, act as effective and tunable π-Lewis acid catalysts in alkene, alkyne and CO2 hydrosilylation.

A series of mononuclear Salen-supported gallium amido/alkoxide derivatives were prepared and structurally characterized and subsequently used as initiators in rac-lactide ring-opening polymerisation (ROP). The reaction of variously substituted salen ligands (1a-1f) with 0.5 equiv of Ga2(NMe2)6 allowed the isolation of the corresponding (salen)Ga-NM...

The vinyl acetate (VAc) radical polymerization initiated by V-70 at 30 °C in the presence of [CoII(OPN)2] (OPN = deprotonated 9-oxyphenalenone), 1, leads to PVAc of lower molecular weight (MW) than expected for organometallic-mediated radical polymerization (OMRP), whether reversible termination or degenerate transfer conditions are used. This repr...

This review provides a summary, including spectroscopic and structural data, of the metal complexes accessible with mono-oxide, sulfide and selenide bis(diphenylphosphino)amine (DPPA)-based ligands and their N-substituted/functionalized derivatives. The nature of the E (O, S, Se) donor in these mixed P,P. E donor ligands strongly influences the nat...

The reactivity of the N-functionalized DPPA-type ligands (Ph2P)2N(p-Z)C6H4 [Z = H (1a), SMe (1b), OMe (1c)] with AgBF4 was investigated and revealed an unexpected influence of the para substituent Z of the N-aryl ligand. In acetone, the mononuclear bis-chelated [Ag{(1a–1c)-P,P}2]BF4 (2a·BF4–2c·BF4) and dinuclear bridged [Ag2{μ2-(1a–1c)-P,P}2](BF4)2...

Tri-organyl and tri-coordinate N-heterocyclic carbene Zn-NHC alkyl cations (nNHC)2Zn-Me+ (nNHC = C2-bonded-IMes/-IDipp; 3+ and 4+) were first synthesized and structurally characterized via ionization of the corresponding neutral precursors (NHC)ZnMe2 with [Ph3C][B(C6F5)4] in the presence of 1 equiv. of free NHC. Cations 3+-5+ are the first Zn catio...

Starting from the short-bite ligands N-thioether-functionalized bis(diphenylphosphino)amine-type (Ph2P)2N(CH2)3SMe (1) and (Ph2P)2N(p-C6H4)SMe (2), the Fe(II) complexes [FeCl2(1)]n (3), [FeCl2(2)]2 (4), [Fe(OAc)(1)2]PF6 (5), and [Fe(OAc)(2)2]PF6 (6) were synthesized and characterized by Fourier transform IR, mass spectrometry, elemental analysis, a...

The aim of this review is to highlight how the diversity generated by N-substitution in the well-known short-bite ligand bis(diphenylphosphino)amine (DPPA) allows a fine-tuning of the ligand properties and offers a considerable scope for tailoring the properties and applications of their corresponding metal complexes. The various N-substituents inc...

The present contribution highlights the most recent and representative developments on the use of Ga and In species in homogeneous catalysis. Recent studies of various ligand-supported Ga(III) and In(III) compounds in cyclic esters polymerization catalysis for the production of biodegradable polyester materials are also included. Various organic tr...

The coordination of two heterofunctional P,P,S ligands of the N-functionalized DPPA-type bearing an alkylthioether or arylthioether N-substituent, (Ph2P)2N(CH2)3SMe (1) and (Ph2P)2N(p-C6H4)SMe (2), respectively, toward cobalt dichloride was investigated to examine the influence of the linker between the PNP nitrogen and the S atoms. The complexes [...

The reaction of 1 equiv of [M(CH2Ph)4] (M = Zr, Hf) and 1,3-bis(3,5-di-tert-butyl-2-hydroxyphenyl)imidazolinium chloride [tBu(OCO)H3, 1] cleanly yielded the corresponding M-NHC chloro benzyl derivatives [[tBu(OCO)]M(Cl)(CH2Ph)] (2Zr and 2Hf) along with 3 equiv of toluene. For both metal complexes, the effective formation of a (κ3-OCO) metal chelate...

Starting from the short-bite ligands N-thioether-functionalized bis(diphenylphosphino)amine-type (Ph2P)2N(CH2)3SMe (1) and (Ph2P)2N(p-C6H4)SMe (2), the Fe(II) complexes [FeCl2(1)]n (3), [FeCl2(2)]2 (4), [Fe(OAc)(1)2]PF6 (5), and [Fe(OAc)(2)2]PF6 (6) were synthesized and characterized by Fourier transform IR, mass spectrometry, elemental analysis, a...

Reaction of the diphosphine (P,P) ligand N(PPh2)2(n-PrSMe) (1) or N(PPh2)2(p-(SMe)C6H4) (2) with [Ni(NCMe)6][BF4]2 in a 2:1 molar ratio afforded the bis-chelated, dicationic Ni(II) complexes [Ni(1)2][BF4]2 (3) and [Ni(2)2][BF4]2 (4), respectively. Both complexes were characterized in solution by various spectroscopic techniques and in the solid sta...

The P,O-type phosphinophenol proligands (1∙H, 2-PPh2-4-Me-6-Me-C6H2OH; 2∙H, 2-PPh2-4-Me-6-tBu-C6H2OH) readily react with one equiv. of ZnEt2 to afford in high yields the corresponding Zn(II)-ethyl dimers of the type [(κ2-P,O)Zn-Et]2 (3 and 4) with two μ-OPh bridging oxygens connecting the two Zn(II) centers, as determined by X-ray diffraction (XRD)...

The reactions of TCNE- and TCNQ-functionalized (TCNE: tetracyanoethylene and TCNQ: 7,7',8,8'-tetracyanoquinodimethane) zwitterionic benzoquinonemonoimines with a Cu(i)-BIAN complex (BIAN = bis(o,o'-bisisopropylphenyl)acenaphthenequinonediimine) have been investigated and found to follow a diversity of interesting patterns. The complexes [Cu(BIAN)(N...

A novel family of Al(III) complexes supported by a tridentate, dianionic N-heterocyclic carbene bis-phenolate ligand ((OCO)(2)) was prepared via various synthetic routes, and the derived compounds were all structurally characterized. The methane elimination reaction of the protio ligand N,N'-bis(2-hydroxy-3,5-di-tert-butylphenyl)-4,5-dihydroimidazo...

The present contribution comprehensively reviews the synthesis, structural characterization and current applications of group 13 metal complexes supported by heteroatom-bonded carbene ligands. Detailed structural analysis and comparison of the structure/reactivity trends of group 13 metal carbene species constitute the primary purpose of the presen...

Four novel Zinc–NHC alkyl/alkoxide/chloride complexes (4, 5, 9 and 9′) were readily prepared and fully characterized, including X-ray diffraction crystallography for 5 and 9′. The reaction of N-methyl-N′-butyl imidazolium chloride (3.HCl) with ZnEt2 (2 equiv.) afforded the corresponding [(CNHC)ZnCl(Et)] complex (4) via a protonolysis reaction, as d...

Two new Ar-BIAN Cu(II) complexes (where Ar-BIAN = bis(aryl-imino)acenaphthene) of formulations [CuCl2(Mes-BIAN)] (1) (Mes = 2,4,6-Me3C6H2) and [CuCl2(Dipp-BIAN)] (2) (Dipp = 2,6-iPr2C6H3) were synthesised by direct reaction of CuCl2 suspended in dichloromethane with the respective ligands Mes-BIAN (L1) and Dipp-BIAN (L2), dissolved in dichlorometha...

Starting from the new ligands bis(diphenylphosphino)(N-4-(methylthio)phenyl)amine (4, N(PPh2)2(p-C6H4)SMe) and its monosulfide derivative (Ph2P)N{P(S)Ph2}(p-C6H4)SMe (4·S), we have prepared and characterized, including by X-ray crystallographic studies, their Ni(II) complexes [NiCl2{(Ph2P)2N(p-C6H4)SMe-P,P}] (5) and [NiCl2{(Ph2P)N{P(S)Ph2}(p-C6H4)S...

We describe the synthesis of the new Zn–N-heterocyclic carbene (NHC) alkoxide complexes [(S,CNHC)ZnCl(OBn)]2 (5) and [(O,CNHC)ZnCl(OBn)]2 (6) for use as ring-opening polymerization (ROP) initiators for lactide polymerization. Complexes 5 and 6 are readily available through an alcoholysis reaction between BnOH and the corresponding Zn–NHC ethyl spec...

A rigid S-functionalized metalloligand is used to pair Janus Au-coated silica microspheres and the resulting assemblies are assessed with optical microscopy. New Pd complexes provide stable molecular interconnects, and the metal centre controls the structure of the linker and provides the desired rigidity, by virtue of its well-established coordina...

This review summarizes the recent progress in the field of S-functionalized N-heterocyclic carbene ligands and their metal complexes. The syntheses of the azolium precursors and of the corresponding metal complexes are discussed as a function of the five different S-containing chemical groups examined here: thiolate, thioether, thiophene, sulfonate...

The coordination chemistry of the DPPA-type functional phosphine bis(diphenylphosphino)(N-thioether)amine N(PPh2 )2 (CH2 )3 SMe (1) and its monosulfide derivative, (Ph2 P)N{P(S)Ph2 }(CH2 )3 SMe (1⋅S), towards Ni(II) precursors has been investigated. The crystal structures of N{P(S)Ph2 }2 (CH2 )3 SMe (1⋅S2 ), [NiCl2 {(Ph2 P)2 N(CH2 )3 SMe-P,P}] (2),...

A variety of N-heterocyclic carbene (NHC) zinc adducts of the type NHC–ZnMe2 [2a, NHC = 1,3-dimesitylimidazol-2-ylidene; 2b, NHC = 1,3-(2,6-iPr2Ph)2-imidazol-2-ylidene; 2c, NHC = 1,3-di-tert-butylimidazol-2-ylidene] and NHC–Zn(C6F5)2 [4a, NHC = 1,3-dimesitylimidazol-2-ylidene; 4b, NHC = 1,3-(2,6-iPr2Ph)2-imidazol-2-ylidene; 4c, NHC = 1,3-di-tert-bu...

New cationic Ag(i) complexes were prepared by reaction of AgBF4 with two thioether-functionalized bis(diphenylphosphino)amine ligands, Ph2PN(p-ArSMe)PPh2 () and Ph2PN(n-PrSMe)PPh2 (), and compared with those obtained from the unfunctionalized ligands Ph2PN(Ph)PPh2 () and Ph2PN(n-Bu)PPh2 (), respectively. The complex [Ag3(μ3-Cl)2(μ2--P,P)3](BF4) (·B...

A series of new cationic and neutral (Ar-BIAN)copper(I) complexes [in which Ar-BIAN = bis(aryl)acenaphthenequinonediimine] was synthesised and characterised by elemental analysis, 1D and 2D NMR spectroscopy and single-crystal Xray diffraction. The cationic complexes of the general formula [Cu(Ar-BIAN)L2]BF4 [L2 = (PPh3)2 (1), dppe (2), dppf (3), (A...

Polylactide (PLA) is an attractive polymeric material due to its origin from annually renewable resources and its biodegradability. The ring-opening polymerization (ROP) of lactide initiated by Lewis acidic and oxophilic metal-based catalysts constitutes the method of choice to access PLA in a controlled and stereoselective manner. The design and s...

This chapter highlights the most recent and representative results on the use of organoaluminum compounds in polymerization catalysis with a special emphasis on discrete Al-incorporating catalysts. The first part of this contribution summarizes recent and noteworthy developments on well-defined Al-based initiators for the controlled (and stereocont...

Zinc alkyl cations supported by N,N-BIAN-type bidentate ligands were found to be highly active in the immortal ROP of ε-caprolactone to yield narrowly disperse and chain length-controlled poly(ε-caprolactone), whether in solution or bulk polymerization conditions.

We report a one-step synthesis for new N-aryl-N0-thioether imidazolium salts that are precursors to (S,CNHC) ligands in N-heterocyclic carbene (NHC) complexes. The crystal structure of the N-(2,6- diisopropylphenyl)-N0-ethyl-(ethyl)-sulfide imidazolium hexafluorophosphate 8 3 HPF6 was determined by X-ray diffraction and revealed H-bonding interacti...

The synthesis of bis(thioether)-functionalized imidazolium salts, the characterisation of the first S,C(NHC),S free carbene ligand and the corresponding Ag(i) and Pd(ii) functional carbene complexes are reported. The latter have been prepared from the isolated Ag(i) carbene complexes using the transmetallation procedure or by reaction of the imidaz...

We report the preparation of bromo-aryl functionalized bis(diphenylphosphino)amine ligands of the type Ph2PNArPPh2 (1, Ar = p-BrC6H4; 2, Ar = p-BrC6H4–C6H4) and their coordination properties. Mono- and dinuclear complexes were formed with Cu(I), Au(I), Pd(II), Pt(II) and tetranuclear cobalt carbonyl clusters were obtained. The crystal structures of...

The Ag(I) and hemilabile Pd(II) carbene complexes obtained from novel thioether-functionalized imidazolium salts synthesised in one-step illustrate the diversity of coordination modes of these new S, C(NHC) ligands.

A new imidazolinium [(SIBiphen)H](BF4) was synthesized in three steps from 2-aminobiphenyl. The reaction of the salt with Pd(OAc)2, NaI and t-BuOK gave a dimeric Pd(II) complex [(SIBiphen)PdI2]2, which was analyzed by an X-ray diffraction study. The reaction of [Pd(allyl)Cl]2, the imidazolinium salt and t-BuOK in THF at −78°C gave the monomeric Pd...