Decarboxylation syntheses of transition metal organometallics,II.trans-carbonyl(polyhalogenophenyl)bis(triphenylphosphine)rhodium(I) compounds

Summary The rhodium(I) carboxylates,trans-RhO₂CR(CO)(PPh₃)₂ (R = C₆F₅, C₆Cl₅,p-HC₆F₄,m-HC₆F₄,o-HC₆F₄,p-McOC₆F₄, 4,5-H₂C₆F₃, 3,5-H₂C₆F₃, or 2,6-F₂C₆H₃, have been prepared by reaction of RhH(CO)(PPh₃)₃ with the appropriate polyhalogenobenzoic acids in ethanol and/or by reaction oftrans-RhCl(CO)(PPh₃)₂ with the appropriate thallous carboxylates in benzene. Decarboxylations with formation of polyhalogenoarylrhodium(I) compounds,trans-RhR(CO)(PPh₃)₂ (R = C₆F₅, C₆Cl₅,p-HC₆F₄,m-HC₆F₄,p-MeOC₆F₄, 4,5-H₂C₆F₃ or 3,5-H₂C₆F₃), have been achieved either by decomposition of the corresponding rhodium(I) carboxylates in pyridine or by reaction oftrans-RhCl(CO)(PPh₃)₂ and the thallous carboxylates in pyridine, but the derivatives R =o-HC₆F₄ or 2,6-F₂C₆H₃ could not be obtained by this method. The rate of decarboxylation decreased in the sequence R = C₆F₅ >p-MeOC₆F₄ >p-HC₆F₄ >m-HC₆F₄ > 4,5-H₂C₆F₃ > 3,5-H₂C₆F₃.Part 1, ref. 10.Preliminary communication, ref. 9.     

Untersuchungen zu Synthese und Reaktionen von Fluorphenylquecksilber-Derivaten mit den Liganden 2-FC6H4, 2,6-F2C6H3 und 2,4,6-F3C6H2

Investigations on Syntheses and Reactions of Fluorophenylmercury Compounds with the Ligands 2-FC₆H₄, 2,6-F₂C₆H₃, and 2,4,6-F₃C₆H₂ 2,6-F₂C₆H₃HgCl and 2,4,6-F₃C₆H₂HgCl are synthesized via the reactions of the corresponding phenylmagnesium compounds and HgCl₂. 2-FC₆H₄HgCl is selectively obtained only in a reaction involving intermediately formed Cd(2-FC₆H₄)₂. The diphenylmercury derivative Hg(2,4,6-F₃C₆H₂)₂ is obtained while stirring a dichloromethane solution of 2,4,6-F₃C₆H₂HgCl for several days. The direct mercuration of 1,3,5-trifluorobenzene with Hg(OCOCF₃)₂ yields, depending on the stoichiometry, 2,4,6-trifluorophenylmercury trifluoroacetate and 1,3-bis(trifluoroacetatomercuri)-2,4,6-trifluorobenzene which is converted into the corresponding chloromercuri derivative by treatment with hydrochloric acid in CH₃CN. As a product of the reaction of 1,3,5-trifluorobenzene and HgO in CH₃COOH only 2,4,6-trifluorophenylmercury acetate is isolated although spectroscopic evidence has been found for double and triple mercurated derivatives. All compounds are characterized by elemental analyses, nmr and mass spectra. The reaction of Hg(2,4,6-F₃C₆H₂)Cl and Cd(CF₃)₂ · 2 CH₃CN gives Hg(2,4,6-F₃C₆H₂)CF₃ which slowly dismutates in CH₂Cl₂ solution into Hg(2,4,6-F₃C₆H₂)₂ and Hg(CF₃)₂. The ligand exchange of Hg(2,4,6-F₃C₆H₂)₂ and TeCl₄ selectively gives Te(2,4,6-F₃C₆H₂)₂Cl₂ and Hg(2,4,6-F₃C₆H₂)Cl. Transmetalations of Hg(2,4,6-F₃C₆H₂)₂ and gallium or tin give NMR spectroscopic evidence for the new derivates Ga(2,4,6-F₃C₆H₂)₃ and Sn(2,4,6-F₃C₆H₂)₄.     

Organolanthanoids : II. Preparation and identification of some organolanthanoid species in solution

The organolanthanoid derivatives R₂M (R  C₆F₅, M  Yb or Eu; R  $\text{o}$-HC₆F₄ or PhCC, M  Yb) have been prepared by reaction of the corresponding diorganomercury compounds with ytterbium or europium metal in tetrahydrofuran at room temperature, and ($\text{o}$-HC₆F₄)₂Yb has been obtained by an analogous reaction at 0°C. The compounds were identified by determination of the amounts of polyfluoroarene or phenylacetylene and lanthanoid ions formed on acidolysis of the filtered reaction mixtures. Reaction of samarium with bis(pentafluorophenyl)mercury and of ytterbium with bis(2,3,4,5-tetrafluorophenyl) mercury at room temperature gives more complex products including RMF₂, MF₂ and RMF derivatives (R  C₆F₅, M  Sm; R  $\text{o}$-HC₆F₄, M  Yb), polyfluoropolyphenyls, and more complex organometallic species. These are considered to be derived from decomposition of initially formed (C₆F₅)₂Sm, (C₆F₅)₃Sm, and ($\text{o}$-HC₆f₄)₂Yb derivatives. The decomposition paths include fluoride elimination to give polyfluorobenzynes, reduction of polyfluoroaryl groups by lanthanoid(II) species, and hydrogen abstraction from tetrahydrofuran.     

Darstellung und Eigenschaften neuer Tris(fluoraryl)borane

Preparation and Properties of New Tris(fluoroaryl)boranes B(2-FC₆H₄)₃, B(4-FC₆H₄)₃, B(2,6-F₂C₆H₃)₃ and B(C₅F₄N)₃ are prepared from the reactions of RMgX with boron trifluoride, B(OC₆F₅)₃ and B(SC₆F₅)₃ from C₆F₅XH (X = O, S) and boron trichloride. The synthetic routes and the properties of these mainly new compounds are described.     

Synthesis, NMR spectroscopic characterisation and reactions of 2,6-difluorophenylxenon fluoride, 2,6-F2C6H3XeF

[2,6-F₂C₆H₃Xe][BF₄] is quantitatively transferred into 2,6-F₂C₆H₃XeF in reactions with [NMe₄]F. The latter has been isolated as a colourless solid which is stable in dichloromethane solution at room temperature for approximately 1 h. 2,6-F₂C₆H₃XeF readily reacts with Me₃SiX (X = Cl, Br, CN, NCO, OCOCF₃, OSO₂CF₃, C₆F₅, 2,6-F₂C₆H₃) to give compounds of general compositions 2,6-F₂C₆H₃XeX which were identified by multinuclear NMR experiments. Evidence was found for C₆H₅Xe(2,6-F₂C₆H₃) as a product of the reaction with C₆H₅SiF₃.     

Synthesen und Eigenschaften neuer Tris(fluorphenyl)antimon- und -bismut-Verbindungen. Kristallstruktur von Tris(2,6-difluorphenyl)bismut

Syntheses and Properties of Some New Tris(fluorophenyl)antimony and -bismuth Compounds. Crystal Structure of Tris(2,6-difluorophenyl)bismuth (2,6-F₂C₆H₃)₃Bi, (2,4,6-F₃C₆H₂)₃Bi, and (2,6-F₂C₆H₃)₃Sb are prepared via Grignard reactions with BiBr₃ and SbBr₃, respectively. The syntheses and properties of the new compounds and the crystal structure of (2,6-F₂C₆H₃)₃Bi are described. From the reaction of BiBr₃ with Ag(OCOC₆H₃F₂) the bismuth benzoate Bi(OCOC₆H₃F₂)₃ is formed in 83% yield. Attempts to prepare (2,6-F₂C₆H₃)₃Bi by decarboxylation of the bismuth benzoate failed.     

Neue Synthesen und Kristallstrukturen von Bis(fluorphenyl)quecksilber,Hg(Rf)2 (Rf = C6F5, 2, 3, 4, 6‐F4C6H, 2, 3, 5, 6‐F4C6H, 2, 4, 6‐F3C6H2, 2, 6‐F2C6H3)

New Syntheses and Crystal Structures of Bis(fluorophenyl) Mercury, Hg(R_f)₂ (R_f = C₆F₅, 2, 3, 4, 6‐F₄C₆H, 2, 3, 5, 6‐F₄C₆H, 2, 4, 6‐F₃C₆H₂, 2, 6‐F₂C₆H₃) Bis(fluorophenyl) mercury compounds, Hg(R_f)₂ (R_f = C₆F₅, C₆HF₄, C₆H₂F₃, C₆H₃F₂), are prepared in good yields by the reactions of HgF₂ with Me₃SiR_f. The crystal structures of Hg(2, 3, 4, 6‐F₄C₆H)₂ (monoclinic, P2₁/n), Hg(2, 3, 5, 6‐F₄C₆H)₂ (monoclinic, C2/m), Hg(2, 4, 6‐F₃C₆H₂)₂ (monoclinic, P2₁/c) and Hg(2, 6‐F₂C₆H₃)₂ (triclinic, P1) are described.     

Decarboxylation syntheses of transition metal organometallics. III polyfluorophenylplatinum(II) complexes with nitrogen donor ligands

Summary The platinum(II) carboxylates,trans-Pt(O₂CR)₂(py)₂ and Pt(O₂CR)₂bpy (R=C₆F₅,p-HC₆F₄,m-HC₆F₄, oro-HC₆F₄; bpy=2,2-bipyridyl), have been prepared by reactions oftrans-Pt(OH)₂(py)₂ or Pt(OH)₂bpy with the appropriate polyfluorobenzoic acids, whilst [Pt(py)₄](O₂CC₆F₅)₂ has been obtained from reaction oftrans-PtCl₂(py)₂ with thallous pentafluorobenzoate in pyridine at room temperature. In boiling pyridine, the platinum(II) polyfluorobenzoates undergo either decarboxylation givingtrans-PtR₂(py)₂ and PtR₂bpy (R= C₆F₅,p-HC₆F₄, orm-HC₆F₄) complexes or substitution, giving [Pt(py)₄](O₂CC₆F₄H-o)₂ and [Ptbpy(py)₂](O₂CC₆F₄H-o)₂. Reactions oftrans-PtX₂(py)₂ and PtX₂bpy (X=Cl or Br) with appropriate thallous polyfluorobenzoates in boiling pyridine have yielded the complexestrans-PtR₂(py)₂, PtR₂bpy, PtCl(R)bpy (R=C₆F₅,p-HC₆F₄, orm-HC₆F₄ in each case),trans-PtCl(R)(py)₂ (R = C₆F₅ orm-HC₆F₄),trans-PtBr(C₆F₅)(py)₂, and PtBr(C₆F₅)bpy. The complexestrans-PtR₂(py)₂ (R=C₆F₅ orp-HC₆F₄) have also been prepared from potassium tetrachloroplatinate(II) and the appropriate thallous polyfluorobenzoate in boiling py, andtrans-Pt(C₆F₅)₂(py)₂ has been similarly obtained fromcis-PtCl₂(py)₂ and C₆F₅CO₂Tl. Significant decarboxylation was not observed on reaction oftrans-PtCl₂(py)₂ or PtCl₂bpy with thallous 2,3,4,5-tetrafluorobenzoate.Part II, ref. 4;Preliminary communication, ref. 3;     

Organomercury compounds XX Reactions of lithium polyfluorobenzenesulphinates with mercuric salts

The lithium polyfluorobenzenesulphinates, Li O₂SR (R = C₆F₅, $\text{p}$-HC₆F₄, $\text{m}$-HC₆F₄, or $\text{o}$-HC₆F₄), and the dilithium tetrafluorobenzenedisulphinates, $\text{p}$- and $\text{o}$-(LiO₂S)₂C₆F₄, have been prepared by reaction of the appropriate polyfluoroaryllithium compounds with sulphur dioxide. All compounds were isolated as hydrates and gave the corresponding $\text{S}$-benzylthiouronium salts on treatment with $\text{S}$-benzylthiouronium chloride. From reactions of the lithium sulphinates with suitable mercuric salts in water, generally at room temperature, the derivatives RHgX (R = C₆F₅, X = Cl, Br, CH₃CO₂, or PhSO₂; R = $\text{p}$-HC₆F₄, X = Cl, Br, or CH₃CO₂; R = $\text{m}$-HC₆F₄, X = Cl or Br; R = $\text{o}$-HC₆F₄, X = Cl), $\text{p}$-(XHg)₂C₆F₄ (X = Cl, Br, or CH₃CO₂), and $\text{o}$-(XHg)₂C₆X₄ (X = Cl or Br) have been prepared. Similarly, the bispolyfluorophenylmercurials R₂Hg (R = C₆F₅, $\text{p}$-HC₆F₄, or $\text{m}$-HC₆F₄) have been prepared from the corresponding lithium sulphinates and either mercuric salts or polyfluorophenylmercuric halides in aqueous $\text{t}$-butanol. A possible mechanism for the sulphur dioxide elimination reactions is discussed.     

Synthesis of (adamantylimido)vanadium(V)-alkyl complexes containing aryloxo ligands and their use as the catalyst precursors for ring-opening metathesis polymerization of norbornene, and ring-opening polymerization of tetrahydrofuran

Various (adamantylimido)vanadium(V) dialkyl complexes containing aryloxo ligands, V(NAd)(CH₂SiMe₃)₂(OAr) [Ad = 1-adamantyl (1); Ar = Ph (a), 4-FC₆H₄ (b), 2,6-F₂C₆H₃ (c), 2,6-Me₂C₆H₃ (d), C₆F₅ (e)], have been prepared and identified. These complexes were employed as the catalyst precursors for ring-opening metathesis polymerization (ROMP) of norbornene (NBE) in the presence of PMe₃ at 80 °C. The activity was strongly affected by the aryloxo substituent and increased in the order: C₆H₅ < 4-FC₆H₄ < 2,6-Me₂C₆H₃ << 2,6-F₂C₆H₃, C₆F₅. The same trend was observed in the ROMPs by the arylimido-aryloxo analogues, V(NAr′)(CH₂SiMe₃)₂(OAr) (2a-e; Ar′ = 2,6-Me₂C₆H₃), under the same conditions, and the activities by the arylimido analogues were generally higher than the adamantylimido analogues in most case. The (imido)vanadium(V) complexes containing O-2,6-F₂C₆H₃ (1,2c) or OC₆F₅ (1,2e) exhibited high catalytic activities, and these results strongly suggest that electronic as well as steric factors play a role. Living ring-opening polymerization of THF proceeded in the presence of V(NAd) (CH₂SiMe₃)(OAr)₂ (Ar = 2,6-Me₂C₆H₃, C₆F₅) and [Ph₃C][B(C₆F₅)₄], affording high molecular weight polymers with narrow molecular weight distributions (ex. M_n = 2.11 × 10⁵, M_w/M_n = 1.18).     

Syntheses of polyfluorophenylcobalt(III) schiff base complexes using organothallium reagents

The complexes RCo(acacen) [R = C₆F₅, p-HC₆F₄, or o-HC₆F₄; H₂acacen = N,N′-ethylenebis(acetylacetonimine)] and RCo(salen) [R = C₆F₅ or p-HC₆F₄; H₂salen = N,N′-ethylenebis(salicylaldimine)] have been prepared by reaction between Co(acacen) or Co(salen) and the appropriate bromobis(polyfluorophenyl)thallium(III) compounds, and have been isolated as pyridinates. Spectroscopic evidence for formation of C₆F₅Co(salophen) [H₂salophen = _N,N′-o-phenylenebis(salicylaldimine)] has also been obtained. The reactivity of the thallium compounds increased in the sequence Ph₂TlBr ? (o-HC₆F₄)2TlBr < (p-HC₆F₄)₂TlBr < (C₆F₅)₂TlBr, and of the cobalt complexes in the sequence Co(salophen) < Co(salen) < Co(acacen). Possible mechanisms are discussed.     

Organothallium compounds : XVII. Halogenobis(polyfluorophenyl)thallium(III) complexes

The preparations, stabilities and structures of the complexes R₂TlX and R₂ LTlX (R = C₆F₅, p-HC₆F₄, or o-HC₆F₄; X = Br or Cl; L = Ph₃PO, 2,2′-bipyridyl (bpy) or Ph₃P) have been examined or (R = C₆ F₅) reinvestigated. The derivatives R₂TlX are monomeric in acetone, from which the complex (p-HC₆F₄)₂ Me₂COTIBr has been isolated. In this solvent, the complexes R₂LTlX (L = Ph₃PO, bpy, or Ph₃P) undergo partial dissociation by loss of L. When L = bpy, there is also slight ionization into R₂LTl⁺ and R₂TlX^?₂. The acceptor properties of R₂TlX compounds towards uncharged ligands decrease R = C₆F₅ ? p-HC₆F₄ > o-HC₆F₄ > Ph. Dimeric behaviour is observed for R₂TIX compounds in benzene, whilst R₂LTlX (L = Ph₃PO or bpy) derivatives show slight but significant association. In the solid state, R₂TlX compounds are considered to be polymeric with five coordinate thallium, and R₂LTlX derivatives to be dimeric with five (L = Ph₃PO) or six (L = bpy) coordinate thallium by contrast with four coordinate dimeric and four or five coordinate monomeric structures previously proposed for the respective pentafluorophenyl derivatives. Halogen bridging is unsymmetrical for R = C₆F₅ or p-HC₆F₄, but may be more symmetrical for R = o-HC₆F₄ when L = Ph₃PO or bpy. Reported structural data for the complexes (C₆F₅)LTlX (L = Ph₃AsO, Ph₃P, Ph₃As, or 1,10-phenanthroline; X = Br or Cl) and (C₆F₅)₂TlCl^?₂ are reinterpreted and the proposed structures revised.     

Organothallium compounds XII NMR spectra of some polyfluorophenylthallium (III) compounds

The PMR and ¹⁹F NMR spectra of the complexes R₂TlBr (R = C₆F₅, $\text{o}$-HC₆F₄, $\text{m}$-HC₆F₄, 3,5-H₂C₆F₃, or 3,6-H₂C₆F₃ and R₃Tl(diox) (R = C₆F₅, $\text{m}$-HC₆F₄, or 3,5-H₂C₆F₃; diox = 1,4-dioxan) have been recorded. Proton and fluorine chemical shifts, thallium-proton, thallium-fluorine, fluorine-fluorine, and fluorine-proton coupling constants, and thallium substituent chemical shifts are given and discussed     

Organo group VB chemistry: Part VI. On the electric dipole moments of some substituted tertiary phenylphosphines, -arsines, -stibines and -bismuthines

The dipole moments of the following series of tertiary substituted aryl-group VB compounds were measured: (a) (C₆H₅)₃M and (XC₆H₄)₃M with M = P, As, Sb, Bi and X = 4-F, 4-Cl, 4-CH₃, 3-F, 3-Cl; and (b) (3-XC₆H₄)_3?n PR_n with R = C₆H₅, 4-FC₆H₄ and X = F, Cl. These experimental molecular moments are discussed as a consistent set of data that allows the calculation, within the framework of the vectorial additive method, of suitable group moments, bond moments and configurational parameters.     

Synthesis,Structures and Reactivity of Lanthanoid(II) Formamidinates of Varying Steric Bulk

New reactive, divalent lanthanoid formamidinates [Yb(Form)₂(thf)₂] (Form=[RNCHNR]; R=o‐MeC₆H₄ (o‐TolForm; 1 ), 2,6‐Me₂C₆H₃ (XylForm; 2 ), 2,4,6‐Me₃C₆H₂ (MesForm; 3 ), 2,6‐Et₂C₆H₃ (EtForm; 4 ), o‐PhC₆H₄ (o‐PhPhForm; 5 ), 2,6‐iPr₂C₆H₃ (DippForm; 6 ), o‐HC₆F₄ (TFForm; 7 )) and [Eu(DippForm)₂(thf)₂] ( 8 ) have been prepared by redox transmetallation/protolysis reactions between an excess of a lanthanoid metal, Hg(C₆F₅)₂ and the corresponding formamidine (HForm). X‐ray crystal structures of 2 – 6 and 8 show them to be monomeric with six‐coordinate lanthanoid atoms, chelating N,N′‐Form ligands and cis‐thf donors. However, [Yb(TFForm)₂(thf)₂] ( 7 ) crystallizes from THF as [Yb(TFForm)₂(thf)₃] ( 7 a ), in which ytterbium is seven coordinate and the thf ligands are “pseudo‐meridional”. Representative complexes undergo C? X (X=F, Cl, Br) activation reactions with perfluorodecalin, hexachloroethane or 1,2‐dichloroethane, and 1‐bromo‐2,3,4,5‐tetrafluorobenzene, giving [Yb(EtForm)₂F]₂ ( 9) , [Yb(o‐PhPhForm)₂F]₂ ( 10) , [Yb(o‐PhPhForm)₂Cl(thf)₂] ( 11) , [Yb(DippForm)₂Cl(thf)] ( 12) and [Yb(DippForm)₂Br(thf)] ( 16) . X‐ray crystallography has shown 9 to be a six‐coordinate, fluoride‐bridged dimer, 12 and 16 to be six‐coordinate monomers with the halide and thf ligands cis to each other, and 11 to have a seven‐coordinate Yb atom with “pseudo‐meridional” unidentate ligands and thf donors cis to each other. The analogous terbium compound [Tb(DippForm)₂Cl(thf)₂] ( 13 ), prepared by metathesis, has a similar structure to 11 . C? Br activation also accompanies the redox transmetallation/protolysis reactions between La, Nd or Yb metals, Hg(2‐BrC₆F₄)₂, and HDippForm, yielding [Ln(DippForm)₂Br(thf)] complexes (Ln=La ( 14 ), Nd ( 15 ), Yb ( 16 )).     

Reactions of (η5-C5H5)2Tir compounds with organic cyanides

The syntheses and properties of the titanium(III) complexes Cp₂Tir · R′CN (R = C₆H₅, o-, m-, p-CH₃C₆H₄, CH₂C₆H₅, C₆F₅, Cl; R′ = CH₃, t-C₄H₉, C₆H₅, o-CH₃C₆H₄, 2,6-(CH₃)₂C₆H₃) are described. In the complexes the nitrogen atom of the cyanide ligands is coordinated to the metal. The thermal stabilities of the complexes depend markedly on R and R′; on heating they undergo a novel reaction in which two cyanide ligands are coupled by formation of a CC bond, while the metal is oxidized to titanium(IV).     

Progress in NMR spectroscopy,Volume 11 : edited by J.W. Emsley,J. Feeney and J.R. Sutcliffe,Pergamon Press,Oxford, 1978, vii + 298 pages; $ 40.00 (£ 20)

Protonolysis of the complexes trans-[Pt(PEt₃)₂(R)(Me)] (R = C₆H₅ ; m-MeC₆H₄ ; o-MeC₆H₄ ; m-FC₆H₄ ; p-FC₆H₄ ; m-CF₃C₆H₄ and C₆F₅) by hydrogen chloride in methanol/water ($\text{90}\text{10}$ v/v) selectively cleaves the alkyl group yielding trans-[Pt(PEt₃)₂(R)Cl] and methane. A kinetic study of these reactions suggests that the primary step involves a proton transfer to the carbonmetal σ-bond with release of CH₄ in a three-center transition state.     

Synthesis and Structural Studies of Group 2B Transition Metal Complexes with the Bulky Nitrogen Ligand Bis[ N-(2,6-diisopropylphenyl) imino]acenaphthene

Group 2B transition metal complexes of bis[N-(2,6-diisopropylphenyl)imino]acenaphthene (o,o-iPr₂C₆H₃-BIAN), namely, [Hg(o,o-iPr₂C₆H₃-BIAN)Cl₂] (1), [Zn(o,o-iPr₂C₆H₃-BIAN)₂](ClO₄)₂ (2), and [Cd(o,o-iPr₂C₆H₃-BIAN)₂](ClO₄)₂ (3) have been synthesized and characterized. In complexes 2 and 3, IR, NMR, and conductivity measurements confirm the coordination of two (o,o-iPr₂C₆H₃-BIAN) ligands to the metal center with two discrete perchlorate anions. X-Ray crystal structure of 1 indicates a distorted tetrahedral geometry with two nitrogen atoms from (o,o-iPr₂C₆H₃-BIAN) ligand and two chloride atoms coordinating to the Hg(II) center.     

β-Diketiminato Rare-Earth Metal Complexes: The Influence of Monoatomic Substituents in the N-aryl Moieties on Structures and Properties

Treatment of β-diketiminate ligands bearing different N-aryl monoatomic substituents [HL^H = (C₆H₅)N = C(Me)CH=C(Me)NH(C₆H₅), HL^F = (2,6-F₂C₆H₃)N=C(Me)CH=C(Me)NH(2,6-F₂C₆H₃), and HL^Cl = (2,6-Cl₂C₆H₃)N=C(Me)CH=C(Me)NH(2,6-Cl₂C₆H₃)] with Ln(CH₂SiMe₃)₃(THF)₂ (Ln = Y and Lu) afforded a variety of β-diketiminato rare-earth metal complexes depending on substituents, namely, phenyl ring C–H bond activated complexes (L')(L^H)Lu(THF) ( 1b , L' = (C₆H₄)N = C(Me)CH=C(Me)N(C₆H₅)), six-coordinate homoleptic complexes (L^H)₃Ln [Ln = Y ( 1aa ), Lu ( 1bb )], five-coordinate monoalkyl complexes (L^F)₂Ln(CH₂SiMe₃) [Ln = Y ( 2a ), Lu ( 2b )], and four-coordinate dialkyl complexes (L^Cl)Ln(CH₂SiMe₃)₂ [Ln = Y ( 3a ), Lu ( 3b )]. All these complexes were characterized with NMR spectroscopy, and lutetium complexes 1b , 1bb and 3b were structurally validated by single-crystal X-ray diffraction analysis. Moreover, dialkyl complexes 3 promoted the polymerization of 2-vinylpyridine (2-VP) to produce atactic poly(2-vinylpyridine) (P2VP) with quantitative yield. On activation with an equimolar amount of [Ph₃C][B(C₆F₅)₄], complexes 3 afforded highly isotactic P2VP with an mm value up to 94 %. Both ¹H NMR spectrum and MALDI-TOF mass analysis of an oligomer indicate that the polymerization was initiated by coordination insertion of 2-VP into the Y-CH₂SiMe₃ bond.     

A first methodical approach to salts with unsymmetrical fluorophenyl(pentafluorophenyl)difluoroiodonium(V) cations [Rf(RF)IF2] (Rf=x-FC6H4, x=2, 3, 4; RF=C6F5)

A promising approach to the unknown type of [Ar′(Ar)IF₂]X salts is offered. x-FC₆H₄IF₄ (x=2, 3, 4) reacts with C₆F₅BF₂ in CH₂Cl₂ and forms [x-FC₆H₄(C₆F₅)IF₂][BF₄] salts in good yields. For [4-FC₆H₄(C₆F₅)IF₂][BF₄] the fluoro-oxidizer property is shown in reactions with weakly reducing agents like E(C₆F₅)₃ (E=P, As, Sb, Bi) and ArI (Ar=4-FC₆H₄, C₆F₅). The fluorine/aryl substitution method is also applied to the synthesis of [(4-FC₆H₄)₂IF₂][BF₄], an example with two identical aryl groups in the difluoroiodonium(V) moiety.