Aspects of transmetallation reactions of 2-Me2NCH2C6H4- and 2,6-(Me2NCH2)C6H3-Metal (Pd,Pt, Hg,Tl) complexes with metal carboxylates and low-valent metal (Pd,Pt) complexes

A study has been made of reactions involving organometallic compounds containing ortho-Me₂NCH₂ substituted aryl ligands. The single step syntheses of the new compounds [(2-Me₂NCH₂C₆H₄)₂TlCl], [ [{(S)-2-Me₂NCH(Me)C₆H₄}₂TlCl], [{(S)-2-Me₂NCH(Me)C₆H₄}TlCl₂], [{2,6-(Me₂NCH₂)₂C₆H₃}TlClBr] and [{2,6-(Me₂NCH₂)₂C₆H₃}HgCl] are described. Stable internal NTl coordination at low temperatures has been established for the C-chiral thallium compounds. Reactions of the other Tl and Hg compounds and of [(2-Me₂NCH₂C₆H₄)₂Hg] with Pd(O₂CMe)₂, and also of the reverse reaction of cis-[(2-Me₂NCH₂C₆H₄)₂Pd] with Hg(O₂CR)₂ or Tl(O₂CR)₃, gave transmetallation of one organo ligand and led to a single mono-organopalladium compound and corresponding by-products. Reaction of cis-[(₂-Me₂NCH₂C₆H₄)₂Pd] with Pd(O₂CR)₂ gave the dimeric compound [{(2-Me₂NCH₂C₆H₄)Pd(O₂CR)}₂]. cis-[(2-Me₂NCH₂C₆H₄)₂Pt] did not react with Pd(O₂CMe)₂, while reaction of trans-[(2-Me₂NCH₂C₆H₄)₂Pt] or cis-[(2-Me₂NC₆H₄CH₂)₂Pt] with Pd(O₂CMe)₂ resulted in decomposition. Upon heating, trans-[(2-Me₂NCH₂C₆H₄)₂Pt] was isomerized to cis-isomer. A redox reaction between [(2-Me₂NCH₂C₆H₄)₂Hg] and [Pt(COD)₂] (COD  1,5-cyclo-octadiene) and [Pd₂(DBA)₃] (DBA  dibenzylideneacetone) gave the cis-isomers of [(2-Me₂NCH₂C₆H₄)₂M] (M  Pd, Pt).The results are discussed in terms of influence of internal coordination of the CH₂NMe₂ group. It is concluded that although internal coordination of the CH₂NMe₂ ligand can stabilize metal—carbon bonds it cannot prevent cleavage of such bonds by electrophiles. In this respect, there is no difference in the behaviour of Hg(O₂CR)₂ and Tl(O₂CR)₃. The reactions are influenced by the metal—nitrogen bond strength, which follows the order PtN > PdN > HgN, TlN. The reactivity of Pt compounds is greatly influenced by their structure and type of ligand. It is proposed that cleavege of PdC bonds occurs mainly by a mechanism involving direct electrophilic attack at the carbon centre.     

Group IB organometallic chemistry: XXXIII. ArAuPPh3, ArAu(CNR), (ArAu)n and Ar4Cu2Au2 compounds in which the aryl group contains 2-MeO, 2,6-(MeO)2, 2-Me2N, 2-Me2NCH2 and (S)- or (R)-2-Me2NCHMe substituents as potential ligands

The synthesis and structural characterization by ¹H NMR and ¹⁹⁷Au Mössbauer spectroscopy as well as by chiral labelling of the built-in ligands of three different types of arylgold(I) compounds is described.¹⁹⁷Au Mössbauer data revealed that the benzyl- and arylgold(I) triphenylphosphine complexes which bear potential coordinating substituents at an ortho position still contain linearly coordinated Au^I with 2c-2e gold(I)carbon bonds. The observation of isochronous NME resonances in (S)-2-Me₂NCH(Me)C₆H₄AuPPh₃ confirms that no additional intramolecular AuN coordination occurs in solution. Preliminary results of an X-ray diffraction study of 2,6-(MeO)₂C₆H₃AuPPh₃ are reported (R = 0.040, PAuC₁ angle 172.6°. Unsymmetrical AuC₁C₂ and AuC₁C₆ angles of 126.4 and 117.4°, respectively).Pure, uncomplexed arylgold(I) compounds have been isolated from the reaction of diarylgoldlithium compounds (arylaurates) with trimethyltin bromide. (S)-2-Me₂NCHMeC₆H₄Au has a dimeric structure which most likely consists of two monomeric units associated by intermolecular AuN coordination thus forming a ten-membered chelate ring. The structure of insoluble 2-Me₂NCH₂C₆H₄Au and 2-Me₂NC₆H₄Au are less clear. The former compound probably has a structure similar to (S)-2-Me₂NCHMeC₆H₄Au (IS/QS values for two-coordinate Au^I centers). However, the strongly deviating IS and QS values of 2-Me₂NC₆H₄Au indicate that a polynuclear structure for this compound similar to that proposed for 2-Me₂NC₆H₄Cu cannot be excluded (a polymeric structure containing 2-Me₂NC₆H₄ groups which span three Au atoms by 3c-2e Au₂C bonds and AuN coordination).The mixed Au/Cu cluster (2-Me₂NCH₂C₆H₄)₄Au₂Cu₂ is accessible via the $\text{1}\text{2}$ reaction of (2-Me₂NCH₂C₆H₄)₄Au₂Li₂ with CuI. Molecular weight and ¹H NMR studies point to a tetranuclear structure in solution, while mass spectrometry shows fragment ions with m/e corresponding to (2-Me₂NCH₂C₆H₄)₃Au₂Cu₂⁺, (2-Me₂NCH₂C₆H₄)₃Cu₂Au⁺, (2-Me₂NCH₂C₆H₄)₂CuAu₂⁺ and of (2-Me₂NCH₂C₆H₄)₂Au⁺.     

N-(2-吡咯甲基)-1-苯基乙亚胺·二甲基铝的合成、结构及其催化丙交酯的活性

通过席夫碱配体N-（2-吡咯甲基）-1-苯基乙亚胺与三乙基铝按物质的量之比为1：1在无氧无水的条件下反应,合成了席夫碱铝的有机金属化合物N-（2-吡咯甲基）-1-苯基乙亚胺·二甲基铝。其结构分别用核磁氢谱、碳谱,元素分析和X射线单晶衍射技术进行了表征。铝化合物在催化外消旋丙交酯开环聚合反应中表现出了中等的活性并得到了以等规聚合为主的高聚物。     

N-(2-吡咯甲基)-1-苯基乙亚胺·二甲基铝的合成、结构及其催化丙交酯的活性

通过席夫碱配体N-（2-吡咯甲基）-1-苯基乙亚胺与三乙基铝按物质的量之比为1：1在无氧无水的条件下反应,合成了席夫碱铝的有机金属化合物N-（2-吡咯甲基）-1-苯基乙亚胺·二甲基铝。其结构分别用核磁氢谱、碳谱,元素分析和X射线单晶衍射技术进行了表征。铝化合物在催化外消旋丙交酯开环聚合反应中表现出了中等的活性并得到了以等规聚合为主的高聚物。     

Group IB organometallic chemistry : XXXII. Arylcopper compounds ArnCun as intermediates in organometallic synthesis. Single-step synthesis and dynamic NMR spectroscopy of diorganotin dihalides Ar2-nRnSnX2 (Ar  2-Me2NCH2C6H4 or (S)-2-Me2NCHMeC6H4; n  0 or 1)

The selective, single-step synthesis of (2-Me₂NCHZC₆H₄)RSnX₂, in which Z  H or Me, R  Me or Ph and X  Cl or Br, starting from the tetranuclear copper cluster compound (2-Me₂NCHZC₆H₄)₄Cu₄ and RSnX₃ is described. Reaction of (2-Me₂NCH₂C₆H₄)₄Cu₄ with SnBr₄ in a 1/2 molar ratio afforded (2-Me₂NCH₂C₆H₄)₂SnBr₂ in almost quantitative yield.¹H NMR spectroscopic data of these novel compounds, which are monomeric in solution, indicate that: (i) intramolecular SnN coordination renders the Sn atom in (2-Me₂NCHZC₆H₄)RSnX₂ pentacoordinate, with the organo ligands residing in the equatorial plane of a trigonal bipyramidal structure, and the Sn atom in (2-Me₂NCH₂C₆H₄)₂SnBr₂ hexacoordinate, with trans organo groups and a cis arrangement for the Br and the N atoms; (ii) in pyridine the Sn atom in (2-Me₂NCHZC₆H₄)RSnX₂ becomes hexacoordinate by complex formation with the solvent but that intramolecular SnN coordination has been retained.The stereochemical lability of the pentacoordinate Sn center in the diorganotin dihalides (2-Me₂NCHZC₆H₄)RSnX₂, which contain a dissymmetrical equatorial plane, has been established on the basis of the dynamic NMR spectra of     

Reactivity of 6-(2-tolyl)- and 6-(2,6-xylyl)-2,2′-bipyridines with palladium(II) derivatives. Selective C(sp)H vs. C(sp)H activation

Two new 6-substituted 2,2′-bipyridines, L, 6-(2-tolyl)bipy, L¹, and 6-(2,6-xylyl)bipy, L², have been synthesized. Their reactions with Na₂[PdCl₄] or {Pd(OAc)₂} afford either 1:1 adducts [Pd(L)X₂] (X=Cl, OAc) or five-membered cyclometallated derivatives [Pd(L¹-H)X] arising from C(sp²)H activation. From the chloro-alkyl intermediates [Pd(L)(Me)Cl], in the presence of Na[BAr′₄] (Ar′=3,5-(CF₃)₂C₆H₃), cationic species [Pd(L)(Me)(S)]⁺ (L=L¹, L²; S=CH₃CN) can be obtained. At variance, in less coordinating solvents, e.g. dichloromethane, unexpected activation of a C(sp³)H bond occurs with loss of methane, to afford 6-membered cyclometallated derivatives. The latter species were isolated as [Pd(L-H)(PPh₃)][BAr′₄].     

The chemical oxidation and electronic spectra of the complexes trans-[M(CNR)2(Ph2PCH2CH2PPh2)2] (M = Mo or W)

Oxidation of the complexes $\text{trans}$-[M(CNR)₂(dppe)₂] (A) (M = Mo or W; R = Me, Bu^t or CH₃C₆H₄-$\text{4}$; dppe = Ph₂PCH₂CH₂PPh₂) with diiodine or silver (I) salts gives the paramagnetic cations $\text{trans}$-[M(CNR)₂(dppe)₂]⁺, (M = Mo, R = CH₃C₆H₄-$\text{4}$; M = W, R = Bu^t) and $\text{trans}$-[M(CNR)₂(dppe)₂]²⁺ (M = Mo, R = Me or CH₃C₆H₄-$\text{4}$; M = W, R = Me or Bu^t). Mixtures of products are generally produced when dichlorine or dibromine are the oxidising agents, however pure salts, the seven-coordinate complex cations [MX(CNC₆H₄CH₃-$\text{4}$)₂(dppe)₂]⁺ (B, X = Cl or Br) have been isolated. A simple molecular orbital scheme is proposed for complexes (A) and used to discuss their electronic spectra and their oxidation.     

Alkoxy,amido and thiolato complexes of tris (3, 5-dimethylpyrazolyl)borato(nitrosyl) molybdenum fluoride,chloride and bromide

The complexes Mo{HB(Me₂pyz)₃}(NO)XY {HB(Me₂pyz)₃  HB(3, 5-Me₂C₃HN₂)₃; X=Y=F, Cl or Br; X=F, Y=OEt, NHMe or SBuⁿ; X=Cl, Y=NHR (R=Me Et, Buⁿ, Ph, p-MeC₆H₄), NMe₂ and SR (R=Buⁿ, C₆H₁₁, CH₂Ph, Ph); X=Br, Y=NHMe, NMe₂ and SBuⁿ} have been prepared and characterised spectroscopically. Their properties are generally similar to those of their iodo-analogues.     

Über diphenyl- und bis(3-nitrophenyl)bleidihalogenide und über bis(3-nitrophenyl)bleihalogenokomplexe

Diaryllead dihalides R₂PbX₂ may be prepared easily by treatment of R₂Pb(OAc)₂ (OAcCH₃COO) with HX in acetic acid (R = C₆H₅; X = F, Cl, Br, I. R = 3-NO₂C₆H₄; X = Br, I). (3-NO₂C₆H₄)₂Pb(OAc)₂ forms soluble complexes when dissolved in acetic acid containing an excess of HX; (3-NO₂C₆H₄)₂PbCl₂ may be isolated from those solutions. Treatment of these solutions with CsOAc and [(C₆H₅)₄P]X, respectively, yield the complex salts M_n[(3-NO₂C₅H₄)₂PbX_2+n] (X = Cl; M = Cs, (C₆H₅)₄P; n = 0.5. X = Br; M = Cs; n = 0.5. M = (C₆H₅)₄P; n = 2, as acetic acid solvate).In addition the preparations of [(C₆H₅)₄P]_n[(3-NO₂C₆H₄)₂PbX_2+n] (X = Cl; n = 1. X = Br; n = 1, 2, as acetone solvate) and of (3-NO₂C₆H₄)₂PbF₂ (as hydrate) are described.     

Characterisation of the first authenticated organomercury hydroxide, 4-Me2NC6H4HgOH

4-Me₂NC₆H₄HgOH was prepared from 4-Me₂NC₆H₄HgOAc. Full characterisation showed that it crystallises as discrete molecules, the first example of a true organomercury hydroxide in the solid state. The structures of 4-Me₂NC₆H₄HgOAc and (4-Me₂NC₆H₄)₂Hg are also discussed.     

Preparation and characterization of mono-cyclopentadienylvanadium dihalide bis-phosphine complexes; crystal structure of (η5-C5H5)VCL2(PMe3)2

Mono-cyclopentadienyl complexes CpVX₂(PR₃)₂ and Cp′VX₂ (PR₃)₂ (Cp = η⁵- C₅H₅; Cp′ = η⁵-C₅H₄Me; R = Me, Et; X = Cl, Br) have been prepared by reaction of VX₃(PR₃)₂ with CpM (M = Na, T1, SnBuⁿ3, 1/2 Mg) or Cp′Na. Attempts to prepare analogous complexes with other phosphine ligands, PPh₃, PPh₂ Me, PPhMe₂, Pcy₃, DMPE and DPPE failed. Reduction of CpVCl₂(PEt₃)₂ with zinc or aluminium under CO (1 bar) offers a simple method for the preparation of CpV(CO)₃(PEt₃). The crystal structure of the trimethylphosphine complex CpVCl₂(PMe₃)₂ is reported.     

New organomercury(II) compounds containing intramolecular N → Hg interactions: crystal and molecular structure of [2-(Me2NCH2)C6H4]HgCl and [2-(Me2NCH2)C6H4]Hg[S(S)PPh2]

[2-(Me₂NCH₂)C₆H₄]HgCl (1) was prepared by reacting HgCl₂ with [2-(Me₂NCH₂)C₆H₄]Li in diethyl ether. The reactions of 1 with the sodium or ammonium salt of the appropriate thiophosphinato ligand, in 1:1 molar ratio, afford the isolation of [2-(Me₂NCH₂)C₆H₄]Hg[S(S)PR₂] [R=Me (2), Et (3), Ph (4)], [2-(Me₂NCH₂)C₆H₄]Hg[S(O)PPh₂] (5) and [2-(Me₂NCH₂)C₆H₄]Hg[S(S)P(OⁱPr)₂] (6). The compounds were investigated by IR and multinuclear NMR (¹H, ¹³C and ³¹P) spectroscopy. The molecular structures of 1 and 4 were determined by single-crystal X-ray diffraction. Due to the strong intramolecular coordination of the N atom of the pendant CH₂NMe₂ arm [Hg(1)-N(1) 2.764(6) and 2.725(4) Å in 1 and 4, respectively] both compounds exhibit a T-shaped (C,N)HgX core in the molecular unit, with almost linear arrangement of the covalent bonds [C(1)-Hg(1)-Cl(1) 176.93(18)° in 1, and C(1)-Hg(1)-S(1) 169.54(16)° in 4]. The crystals of 1 contain discrete monomeric molecules, while the crystals of 4 contain dimer associations built through asymmetric bridging dithiophosphinato ligands [Hg(1)-S(1) 2.3911(16) Å, Hg(1)?S(2a) 3.102(2) Å], thus resulting in an overall pseudo-trigonal bipyramidal (or seesaw) (C,N)HgS₂ core, with the nitrogen atom and the weekly bonded sulfur atom in equatorial positions [N(1)-Hg(1)?S(2a) 82.01(10)°].     

1,1′-Disubstituierte Titanocen-dithiolen-Chelate des Typs (η5-Me3EC5H4)2Ti(S2C2R2) (E = C,Si, Ge)

1,1′-Disubstituted Titanocene Dithiolene Chelates of Type (η⁵-Me₃EC₅H₄)₂Ti(S₂C₂R₂) (E = C, Si, Ge) Reaction of the titanocene dichlorides (η⁵-Me₃EC₅H₄)₂TiCl₂ (E = C, 1a ; E = Si, 1b ; E = Ge, 1c ) with the 1,2-dithiolates (NaS)₂C₂H₂, (NaS)₂C₂(CN)₂ or (LiS)₂C₆H₃Me-4 gave the new titanocene dithiolene chelates (η⁵-Me₃EC₅H₄)₂Ti(S₂C₂H₂) ( 2a–c ), (η⁵-Me₃EC₅H₄)₂Ti[S₂C₂(CN)₂] ( 3a–c ) and (η⁵-Me₃EC₅H₄)₂Ti(S₂C₆H₃Me-4) ( 4a–c ). These have been characterized by ¹H NMR, IR, and mass spectroscopy, and have been compared with the unsubstituted η⁵-C₅H₅ analogues 2d, 3d and 4d . Activation energies for the chelate ring inversion in solution of 2a–c, 3a–d and 4a–c have been estimated by temperature-dependent ¹H NMR spectroscopy.     

Gallium tri-chloride derivatives of the sterically demanding pyridines 2,6-Ar2C6H3N (Ar = 2,4,6-Me3C6H2 or 2,4,6-Pr3C6H2)

The sterically demanding pyridines 2,6-Ar₂C₆H₃N [Ar = 2,4,6-Me₃C₆H₂ (1) or 2,4,6-Prⁱ₃C₆H₂ (2)] were prepared by a palladium catalysed Kumada C–C coupling reaction in high yield. Pyridine 1 reacted with one equivalent of GaCl₃ to afford the tetra-chloro gallate–pyridinium ion pair complex [GaCl₄]⁻[2,6-(2,4,6-Me₃C₆H₂)₂C₆H₃NH]⁺ (3). Contrastingly, pyridine 2 reacted with one equivalent of GaCl₃ to afford the anticipated donor-acceptor complex [GaCl₃{2,6-(2,4,6-Prⁱ₃C₆H₂)₂C₆H₃N}] (4). Complexes 1–4 have been characterised variously by single crystal X-ray diffraction, NMR, CHN, and mass spectrometry.     

Chirale carbonylchloro(η5-cyclopentadienyl)molybdän- und -wolfram-komplexe mit N,N-diphenylphosphino-α-aminosäureestern: (η5-C5H5)(CO)(Cl)M(Ph2P)2NCHRCO2Me (M = Mo,W)

The reaction of (η⁵-C₅H₅)M(CO)₃Cl (M = Mo, W) with optically active bis(diphenylphosphino)-α-(S)-aminoacid methylesters gives (η⁵-C₅H₅)(CO)(Cl)-M(Ph₂P)₂NCHRCO₂Me (II) with an “asymmetric” metal atom. The diastereomers of II can be easily distinguished by their ¹H- and ³¹P-NMR spectra. With l-valine the diastereomers can be separated. The diastereomerie ratio at equilibrium has been determined. The ester group of (OC)₄W(Ph₂P)₂NCH₂CO₂Me can be reduced to the corresponding alcohol without cleavage of the WP and PN bond, respectively.     

Conformational analysis in diastereoisomer equilibria of square-pyramidal [C5H5(CO)2Mo pyridine-2-imine]PF6 complexes

Synthesis and characterization of sonic new square-pyramidal pyridine-2-imine complexes [C₅,H₅,(CO)₂,MoNC₅,H₄,CX=NCH(R₁)(R₂)]PF₆ with X = CH₃, C₆H₅ and chiral amine, 1-phenyl-isobutylamine and amino acid methyl ester H₂NCH(COOCH₃)(R) with (R) = (CH₂C₆H₅) and (C₂H₅) have been reported. In combination with Mo chirality (R) and (S), mixtures of two diastereoisomeric pairs of enantiomers with racemic amine and amino acids were obtained which were separated by fractional cystallization. The diastereoisomers differ in the chemical shift of most of their ¹H NMR signals and interconvert on heating in acetone-d₆ at 80°C for 80 hr and 40°C for 200 hr. On the basis of three conformational determining effects (i) C-H or C-alkyl of the asymmetric centre eclipses the ligand plane, (ii) MC₅H₅/C₆H₅ attraction and (iii) MC₅H₅/alkyl repulsion in order of decreasing significance, the chemical shifts of the C₅H₅ signals, their differences as well as the diastereoisomer ratio at equilibrium for all the complexes has been rationalised.     

Alternativ-Liganden. XXIII. Rhodium(I)-Komplexe mit Donor/Akzeptor-Liganden des Typs (Me2PCH2CH2SiX2 und (2-Me2PC6H4)SiXMe2 (X = F,Cl)

Alternative Ligands. XXIII Rhodium(I) Complexes with Donor/Acceptor Ligands of the Type (Me₂PCH₂CH₂)₂SiX₂ and (2-Me₂PC₆H₄)SiXMe₂ (X = F, Cl) Donor/acceptor ligands of the type (Me₂PCH₂CH₂)₂SiX₂ and (2-Me₂PC₆H₄)SiXMe₂ (X = F, Cl) react with [Rh(CO)₂Cl]₂ (₁) to give the mononuclear complexes RhCl(CO)(Me₂PCH₂CH₂)₂SiX₂ [X = F( 4 ), Cl ( 5 )] and RhCl(CO)[2-Me₂PC₆H₄)SixMe₂]₂ [X = F ( 8 ), Cl ( 9 )], respectively. In case of the ligands (Me₂PCH₂CH₂)₂SiCl₂ ( 3 ) and (2-Me₂PC₆H₆)SiClMe₂ ( 7 ) the Rh(I) complexes formed in the first step partly undergo oxidative addition reactions of SiCl bonds yielding rhodium(III) compounds of low solubility. Only for 8 the coordination shifts Δδ = δ(complex)?δ(ligand) and coupling constants give some indication to possible Rh→Si interactions. However, the molecular structure of 8 determined by X-ray diffraction does not show RhSi or RhF bonding contacts. The new compounds were characterized by analytical (C, H) and spectroscopic investigations (MS, IR,-NMR).     

The solid state structure of arene-mercury(II) complexes from magic-angle spinning carbon-13 NMR and the solution carbon-13 NMR of some complexes of mercury(II) with arenes having bulky aliphatic substituents

The cross-polarization magic angle spinning ¹³C NMR spectra of Hg(SbF₆)₂ - 2 Arene (Arene = C₆HMe₅, 1,2,4,5-C₆H₂Me₄, 1,2,3,4-C₆H₂Me₄, or C₆H₆) have been measured. The spectra of the complexes of C₆HMe₅ and 1,2,4,5-C₆H₂Me₄ are consistent with static η¹-bonding of the mercury to the arene at an unsubstituted carbon atom, while the spectra of the 1,2,3,4-C₆H₂Me₄ and C₆H₆ complexes show the arene to have time-averaged C_s or C₂, and C₆ symmetry respectively, at the temperature of measurement (300 K).The reduced temperature ¹³C NMR spectra of Hg(Arene)_n²⁺ (n = 1 or 2; Arene = 1,3,5-C₆H₃R₃ (R = Me, i-Pr, or t-Bu)) in SO₂ solution are also reported and affirm that in these intramolecularly mobile species the mercury bonds in an η¹-manner, with unsubstituted aryl carbon atoms being the strongly preferred point of mercury attachment. This site preference is further demonstrated by the solution ¹³C NMR spectra of Hg(Arene)_n²⁺ (Arene = 1,2,3,4-C₆H₂-Me₄, n = 1 or 2; Arene = 1,4-C₆H₄R₂, R = Me or t-Bu, n = 1). The spectra of the 1,4-C₆H₄R₂ complexes and Hg(p-C₆H₄-t-BuMe)²⁺ provide clear evidence for steric influence of the binding site.Like Hg(C₆Me₆)₂²⁺, but unlike most of the complexes of substituted benzenes which have been studied, Hg(1,3,5-C₆H₃-i-Pr₃)₂²⁺ exchanges only slowly with excess free ligand.     

The synthesis, structure and ethene polymerization activity of octahedral heteroligated (salicylaldiminato)(β-enaminoketonato)titanium complexes: The X-ray crystal structure of {3-Bu-2-(O)C6H3CHN(Ph)}{(Ph)NC(Me)C(H)C(Me)O}TiCl2

Treatment of the mono(salicylaldiminato)titanium complexes {3-Bu^t-2-(O)C₆H₃CHN(Ar)}TiCl₃(THF) (Ar = C₆H₅, 2,4,6-Me₃C₆H₂ or C₆F₅) with the potassium β-enaminoketonates (C₆H₅)NC(CH₃)C(H)C(R)OK (R = CH₃, CF₃) yielded the first examples of heteroligated (salicylaldiminato) (β-enaminoketonato)titanium dichloride complexes. The complex {3-Bu^t-2-(O)C₆H₃CHN(C₆H₅)}{(C₆H₅)NC(CH₃)C(H)C(CH₃)O}TiCl₂ was structurally characterized by X-ray diffraction and has an orientation with trans-O,O,cis-Cl,Cl, cis-N,N distorted octahedral geometry. These complexes polymerize ethene when activated with MAO; the highest productivity, 5650 kg PE (mol metal)⁻¹ h⁻¹ atm⁻¹, was afforded by {3-Bu^t-2-(O)C₆H₃CHN(C₆F₅)}{(C₆H₅)NC(CH₃)C(H)C(CF₃)O}TiCl₂ at 60 °C.