Some mixed cyclopentadienyl–indenyl zirconium complexes with PhCH2 or PhCH2CH2 substituents in ethylene polymerization

(RCp)(R′Ind)ZrCl₂ complexes 1 – 6 (Cp = cyclopentadienyl; Ind = indenyl; 1 , R = PhCH₂ and R′ = H; 2 , R = PhCH₂ and R′ = PhCH₂; 3 , R = PhCH₂CH₂ and R′ = H; 4 , R = PhCH₂CH₂ and R′ = PhCH₂; 5 , R = o‐Me? PhCH₂CH₂ and R′ = H; 6 , R = o‐Me? PhCH₂ and R′ = H) were synthesized and characterized with ¹H NMR, elemental analysis, mass spectrometry, and infrared spectroscopy. Their catalytic behaviors were compared with those of (Et₃SiCp)(PhCH₂CH₂Cp)ZrCl₂, (PhCH₂Cp)₂ZrCl₂, (PhCH₂‐ CH₂Cp)₂ZrCl₂, (o‐Me? PhCH₂CH₂Cp)₂ZrCl₂, and (Ind)₂ZrCl₂ in ethylene polymerization in the presence of methylaluminoxane. Complex 5 showed high activity up to 2.43 × 10⁶ g of polyethylene (PE)/mol of Zr h, and complex 4 produced PE with bimodal molecular weight distributions. The methyl group at the 2‐position of phenyl in complex 5 increased the activity greatly. The relationships between the polymerization results and the structures were analyzed with NMR spectral data. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1261–1269, 2005     

Reactions of Titanium Alkoxides with N-Methylaminoalcohols

N-methylaminoalkoxides of titanium of the type Ti(OR)_4?n(O · CHR′ · CH₂ · NR″R?)_n where R = Et and Pr¹; n = 1–4; and R′ = R″ = H, R? = Me; R′ = H, R″ = R? = Me; R′ = R″ = R? = Me, synthesized by the reactions of titanium alkoxides with aminoalcohols, show interesting variations in their properties like physical state, volatility and molecular complexity. I.r. and p.m.r. spectra of these derivatives have been recorded. A few interchange reactions with methanol and tert-butanol have also been carried out. These aminoalkoxides get cleaved with acetyl chloride and undergo insertion reactions with phenylisocyanate, thus providing the first examples of insertion reactions in such derivatives.     

Preferred Conformations of Stabilized Phosphorus Ylides

The stabilized phosphorus ylides, Ph₃P=C(CO.R′)CO.OR; 1, R=Et, R′=CH₂P⁺Ph₃; 2, R=R′=Me; 3, R=Et, R′=Me; 4, R=Prⁱ; R′=Me; 5, R=Bu^t; R′=Me, adopt a near planar conformation in the crystal which allows extensive electronic delocalization. The keto and alkoxylic oxygens are oriented and align favorably with the cationoid phosphorus. These conformations bring methyl hydrogens in the ester residue into proximity with the face of a phenyl group and lead to π-shielding and upfield shifts of the ¹HNMR signals of 3 over a wide temperature range (-50–95°C) in (CD₃)₂CO, CDCl₃ and DMSO_d-6. Geometries of 2 and 3, optimized by using the HF 3-21 (G^*) or 6-31 (G^*) basis sets, are very similar to those in the crystal, but semiempirical treatments generate structures in which either the ester or keto moiety is twisted out of plane.

     

The synthesis and spectroscopic properties of some (π-allyl) dicarbonyl-semicarbazonatohalogenomolybdenum(II) complexes

Reaction of [MoX(CO₂(NCMe)₂(η³-C₃H₄R)] in CH₂Cl₂ at room temperature with an equimolar quantity of (R′R″)CNNHCONH₂ gave high yields of the bidentate coordinated semicarbazone complexes [MoX(CO)₂{(R′R″)CNNHCONH₂}(η³-C₃H₄R)] (X = Cl, Br or I; R = H or Me; R′,R″ = H or Me and Me, Et, ⁿPr or Ph) via displacement of two acetonitrile ligands.     

Reaktionen von Lithiumhydridosilylamiden RR′(H)Si–N(Li)R″ mit Chlortrimethylsilan in Tetrahydrofuran und unpolaren Lösungsmitteln: N‐Silylierung und/oder Cyclodisilazanbildung

Reactions of Lithium Hydridosilylamides RR′(H)Si–N(Li)R″ with Chlorotrimethylsilane in Tetrahydrofuran and Nonpolar Solvents: N‐Silylation and/or Formation of Cyclodisilazanes The lithiumhydridosilylamides RR′(H)Si–N(Li)R″ ( 2 a : R = R′ = CHMe₂, R″ = SiMe₃; 2 b : R = R′ = Ph, R″ = SiMe₃; 2 c : R = R′ = CMe₃, R″ = SiMe₃; 2 d : R = R′ = R″ = CMe₃; 2 e : R = Me, R′ = Si(SiMe₃)₃, R″ = CMe₃; 2 f – 2 h : R = R′ = Me, f : R″ = 2,4,6‐Me₃C₆H₂, g : R″ = SiH(CHMe₂)₂, h : R″ = SiH(CMe₃)₂; 2 i : R = R′ = CMe₃, R″ = SiH(CMe₃)₂) were prepared by reaction of the corresponding hydridosilylamines RR′(H)Si–NHR″ 2 a – 2 i with n‐butyllithium in equimolar ratio in n‐hexane. The unknown amines 1 e – 1 i and amides 2 f – 2 i have been characterized spectroscopically. The wave numbers of the Si–H stretching vibrations and ²⁹Si–¹H coupling constants of the amides are less than of the analogous amines. This indicates a higher hydride character for the hydrogen atom of the Si–H group in the amide in comparison to the amines. The ²⁹Si‐NMR chemical shifts lie in the amides at higher field than in the amines. The amides 2 a – 2 c and 2 e – 2 g react with chlorotrimethylsilane in THF to give the corresponding N‐silylation products RR′(H)Si–N(SiMe₃)R″ ( 3 a – 3 c , 3 e – 3 g ) in good yields. In the reaction of 2 i with chlorotrimethylsilane in molar ratio 1 : 2,33 in THF hydrogen‐chlorine exchange takes place and after hydrolytic work up of the reaction mixture [(Me₃C)₂(Cl)Si]₂NH ( 5 a ) is obtained. The reaction of the amides 2 a – 2 c , 2 f and 2 g with chlorotrimethylsilane in m(p)‐xylene and/or n‐hexane affords mixtures of N‐substitution products RR′(H)Si–N(SiMe₃)R″ ( 3 a – 3 c , 3 f , 3 g ) and cyclodisilazanes [RR′Si–NR″]₂ ( 6 a – 6 c , 6 f , 6 g ) as the main products. In case of the reaction of 2 h the cyclodisilazane 6 h was obtained only. 2 c – 2 e show a very low reactivity toward chlorotrimetyhlsilane in m‐xylene and toluene resp.. In contrast to Me₃SiCl the reactivity of 2 d toward Me₃SiOSO₂CF₃ and Me₂(H)SiCl is significant higher. 2 d react with Me₃SiOSO₂CF₃ and Me₂(H)SiCl in n‐hexane under N‐silylation to give RR′(H)Si–N(SiMe₃)R″ ( 3 d ) and RR′(H)Si–N(SiHMe₂)R″ ( 3 d ′) resp. The crystal structures of [Me₂Si–NSiMe₃]₂ ( I ) ( 6 f , 6 g and 6 h ) have been determined.     

Synthesis of N-[chloro(diorganyl)silyl]anilines

A series of N-[chloro(diorganyl)silyl]anilines RR′Si(NR″Ph)Cl (R, R′ = Me, Ph, CH₂=CH, ClCH₂, Cl(CH₂)₃; R″ = H, Me) was prepared via the reaction of diorganyldichlorosilanes with aniline or N-ethylaniline in the presence of triethylamine.     

Darstellung neuer Alkylaminofluorsilane

Preparation of New Alkylaminofluorosilanes Aminofluorosilanes of the composition RSiF₂NR′R″ (R = H, CH₃, C₂H₃, C₆H₅; R′ = Si(CH₃)₃; R″ = C(CH₃)₃; R′ = R″ = i-C₃H₇), as well as C₆H₅SiF₂N[C(CH₃)₂CH₂]₂CH₂ are obtained by the reaction of fluorosilanes with the lithium salts of the corresponding amines in a molar ratio 1:1. The further reaction of these compounds with the lithium salts of alkylamines and anilin leads to the formation of the diaminofluorosilanes RSiFNR′R″NHR? (R? = C(CH₃)₃, i-C₃H₇, C₆H₅). The ¹H, ¹⁹F, ²⁹Si n.m.r. and mass spectra of the above mentioned compounds are reported.     

ÜBER EINIGE REAKTIONEN DER DIALKYLBENZYLPHOSPHINIMIDE

Abstract

Dialkylbenzylphosphine imides C₆H₅CH₂–PRR′[dbnd]N″ (R, R′ = CH₃, C₂H₅; R″ = H, CH₃, Si(CH₃)₃ react with aliphatic and aromatic aldehydes in benzene solution on heating to 80°C directly and in high yields according to a Horner-Wittig-reaction with formation of an olefine whereas ketones like benzophenone and acetophenone only perform an O/NR″ exchange (R″ = H).

Dialkylbenzylphosphinimide C₆H₅CH₂–PRR′[dbnd]N″ mit R, R′ = CH₃, C₂H₅ und R″ = H, CH₃, Si(CH₃)₃ reagieren mit aliphatischen und aromatischen Aldehyden in benzolischer Lösung beim Erwärmen auf 80°C direkt und mit hohen Ausbeuten im Sinne einer Horner-Wittig-Reaktion unter Olefinbildung, während sich mit Ketonen wie Benzophenon oder Acetophenon nur ein O/NR″-Austausch (R″ = H) vollzieht.     

Reaction of Hexafluoroacetone with Aminophosphites Containing the 2,2,2-Trifluoro-1-(trifluoromethyl)ethyl Grouping

Abstract

The reactions of dihaloaminophosphines RNHPF₂, (R=H, Me, tBu) and R₂NPCl₂ (R?Me, Et, SiMe₃; R₂?CH₂(CH₂CMe₂)₂ with LiOCH(CF₃)₂ yield the corresponding aminophosphites R₂NP[OCH(CF₃)₂)_2. Hexafluoroacetone reacts with RNH[OCH(CF₃)₂]₂ as well as MeNHPF₂ and tBuNHPF₂ in good yields to the 1,3,5λ⁵-oxazaphosphetanes 1-4, which show rapid pseudorotation at room temperature.     

Enol ethers and acetals: acylation with dichloroacetyl,acetyl and benzoyl chloride in ionic liquid medium

Synthesis of 4-alkoxy-1,1-dichloro-3-alken-2-ones [CHCl₂C(O)C(R²)C(R¹)-OR, where R, R¹, R² = Et, H, H; Me, Me, H; Et, H, Me; Me, –(CH₂)₂–; Me, –(CH₂)₃–; Et, Et, H; Et, Bu, H; Et, i-Pr, H; Et, i-Bu, H; Me, Ph, H; Me, thien-2-yl, H] from acylation of enol ethers and acetals with dichloroacetyl chloride, in ionic liquid ([BMIM][BF₄] or [BMIM][PF₆]) is reported. The synthesis of alkenones [R³–C(O)C(R²)C(R¹)-OR], where R/R¹/R²/R³ = Et/H/H/Ph, t-Bu/H/H/Ph, Me/-(CH₂)₄/Ph, Me/-(CH₂)₄/Me] from the reaction of enol ethers with benzoyl chloride or acetyl chloride, in ionic liquid [BMIM][BF₄], is also reported. Last products are described for the first time.     

Synthesis and reactivity of metal-containing monomers

Optically active mixed alkoxy orthotitanates with general formula Ti(OR¹)₂(OR²)(OR³) (R¹=Et, Buⁿ; R²=CH₂CH₂OCOC(Me)=CH₂; R³=menthyl, CH(Me)CH₂Me, CH(Ph)CH(NHMe)Me, CH(C₉H₆N)(C₉H₁₄N)) were obtained for the first time by transesterification. The Ti^IV monomers synthesized were characterized by elemental analysis, ozonolysis, and¹H and¹³C NMR and IR spectroscopy. Polymer products with optical activity were obtained by liquid phase radical copolymerization of Ti^IV-containing monomers. For Part 51, see Ref. 1. Deceased. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1739–1743, September, 1999.     

Cumulated double bond systems as ligands : IV. 1H and 13C NMR studies of the intra- and inter-molecular exchange processes of cationic dialkylsulfurdiimine compounds of RhI,IrI and PtII

The preparation and properties are described of trans-[(Ph₃P)₂(CO)M(RNSNR)] [ClO₄] (M  Rh^I, Ir^I; R  Me, Et, i-Pr, t-Bu) and of cis- or trans-[L₂Pt(RNSNR)X] [ClO₄] (X  Cl^?, L  Et₂S, PhMe₂As, PhMe₂P, R  Me, t-Bu; X  CH₃, L  PhMe₂P, R  Me).¹H and ¹³C NMR data show the existence of various isomers in solution which may interconvert via intra- and inter-molecular exchange processes. A general reaction scheme for the intramolecular exchange processes is discussed.     

The First Butyltin(IV) Homo- and Heterobimetallic Diethanolaminates

Equimolar reactions of BuSn(OPrⁱ)₃ with diethanolamines, RN(CH₂CH₂ OH) ₂ (abbreviated as RdeaH₂, where R = H or Me), afford dimeric isopropoxo-bridged six-coordinate butyltin(IV) complexes [{Bu(η³-Rdea)Sn(μ-OPrⁱ)}₂] (R = H ( 1 ), Me ( 2 )). Interactions between BuSn(OPrⁱ)₃ and diethanolamines (RdeaH₂) in a 1:2 molar ratio yield monomeric derivatives of the type [BuSn(Rdea)(RdeaH)] (R = H ( 3 ), R = Me ( 4 )). These homometallic complexes on 1:1 reactions with an appropriate metal alkoxide form monomeric heterobimetallic complexes of the type [BuSn (Rdea)₂ {M(OR′)_n}] (R = H, M = Al, R′ = Prⁱ, n = 2 ( 5 ); R = H, M = Ti, R = Prⁱ, n = 3 ( 6 ); R = H, M = Zr, R′ = Prⁱ, n = 3 ( 7 ); R = Me, M = Al, R′ = Prⁱ, n = 2 ( 8 ); R = Me, M = Ti, R′ = Prⁱ, n = 3 ( 9 ); R = Me, M = Ge, R′ = Et, n = 3 ( 10 )). The driving force behind this work was (i) to explore the utility of homometal complexes ( 1 ) –( 4 ) in assembling a metal alkoxide fragment via a condensation reaction and (ii) to gain insights into the structures of new compounds by NMR spectral data. All of these derivatives have been characterized by elemental analysis, spectroscopic (IR, NMR; ¹H, ²⁷Al, and ¹¹⁹Sn) studies, and molecular weight measurements. ¹¹⁹Sn NMR spectral studies indicate that both the homometallic ( 3 ) and ( 4 ) and heterobimetallic ( 5 ) – ( 9 ) complexes exist in a solution in an equilibrium of six- and five-coordinated tin(IV) species.     

Germylenes and stannylenes based on aminobisphenolate ligands: insertion into the C—Br bond

A reaction of previously synthesized germylenes and stannylenes based on aminobisphenols RN{CH₂[(5-R´)(3-But)C₆H₂(2-O—)]}₂M^II, M = Ge, R = CH²(2-Py), R´ = But (1); M = Ge, R = Et, R´ = Me (2); M = Sn, R = CH₂(2-Py), R´ = But (3); M = Sn, R = Et, R´ = Me (4), containing (tetrylenes 1 and 3) or not containing (tetrylenes 2 and 4) a group capable of additional donation, with allyl bromide leads to the products of the insertion of tetrylenes into the C—Br bond: RN{CH₂[(5-R´)(3-Bu^t)C₆H₂(2-O—)]}₂M(Br)All, M = Ge, R = CH₂(2-Py), R´ = But (5); M = Ge, R = Et, R´ = Me (6); M = Sn, R = CH₂(2-Py), R´ = But (7); M = Sn, R = Et, R´ = Me (8). The structures of obtained derivatives were confirmed by NMR spectroscopy and elemental analysis. The structures of compounds 4, 5, and 7 were studied by X-ray crystallography. Stannylene 4 was found to be monomeric in the solid phase: the coordination number of the Sn atom is 3. The insertion products 5 and 7 are characterized by the coordination number 6 for the central atom.     

Studies on chromium(III) complexes of some new dithiocarbamato ligands

Summary Tris-chelates of chromium(III) have been synthesised with five new dithiocarbamates, [RR'NCS₂]^–, where R=PhCH₂ and R/t'=H, PhCH₂, Me, Et and i-Pr. Magnetic moments together with electronic, i.r. and e.s.r spectra of the complexes have been described. Various ligand-field parameters have been evaluated and discussed.     

Gold(III)pentafluorophenylarylazoimidazole: Synthesis and spectral (H, C, COSY, HMQC NMR) characterisation

Reaction of [Au^III(C₆F₅)₃(tht)] with RaaiR′ in dichloromethane medium leads to [Au^III(C₆F₅)₃ (RaaiR′)] [RaaiR′=p-R-C₆H₄-N=N-C₃H₂-NN-l-R′, (1-3), R = H (a), Me (b), Cl (c) and R′= Me (1), CH₂CH₃ (2), CH₂Ph (3), tht is tetrahydrothiophen]. The nine new complexes are characterised by ES/MS as well as FAB, IR and multinuclear NMR (¹H,¹³C,¹⁹F) spectroscopic studies. In addition to dimensional NMR studies as¹H,¹H COSY and¹H¹³C HMQC permit complete assignment of the complexes in the solution phase.     

Coordination complexes of acetylenic phosphines and diphosphines : V. Acetylene bridged derivatives of dicobalt octacarbonyl

Reactions of the phosphinoacetylenes RR′PCCR″ (R  R′  Ph, R″  H, CF₃, Ph, Me, t-Bu; R  R′  C₆F₅, R″  Ph, Me; R  Ph, R′  Me, R″  Me) with Co₂(CO)₈ have been studied. Complexes of four types have been characterised: (A)(RR′PC₂R″)CO₂(CO)₆ (R  R′  C₆F₅, R″  Ph, Me; R  R′  Ph, R″  t-Bu), (B) (RR′PC₂R″)₂Co₄(CO)₁₀ (R  R′  Ph, R″  H, CF₃, Ph, Me; R  R′  C₆F₅, R″  Me; R  Ph, R′  Me, R″  Me), (C) (RR′PC₂R″)₂Co₂(CO)₆ (R  R′  Ph, R″  t-Bu), (D) (RR′P(O)C₂R″)Co₂(CO)₆ (R  R′  Ph, R″  t-Bu; R  R′  C₆F₅, R  Ph). The complexes were characterised by microanalysis, IR, NMR and where possible mass spectra. Substitution reactions of the complexes with tertiary phosphites are described. In complexes of type (A) only the alkyne function is utilised whereas the tetranuclear compounds (B) have structures in which both alkyne and phosphorus moieties are coordinated. Compounds of type (C) are simple disubstituted phosphine complexes of Co₂(CO)₈ and those of type (D) are μ-alkyne derivatives of acetylenic phosphine oxides. The mechanism of formation of complexes of type (B) is discussed in the light of IR data.     

Reactivity of diacetylplatinum(II) complexes: oxidative addition of alkyl halides and crystal structures of acetyl platinum(IV) complexes

Diacetylplatinum(II) complexes [Pt(COMe)₂(N^N)] (N^N = bpy, 3a; 4,4′-t-Bu₂-bpy, 3b) were found to undergo oxidative addition reactions with organyl halides. The reaction of 3a with methyl iodide and propargyl bromide led to the formation of the cis addition products (OC-6-34)-[Pt(COMe)₂(R)X(bpy)] (R = Me, X = I, 4a; CH₂C≡CH, X = Br, 4k). Analogous reactions of 3a with ethyl iodide, benzyl bromide, and substituted benzyl bromides, 3-(bromomethyl)pyridine, 2-(bromomethyl)thiophene, allyl bromide, and cyclohex-2-enyl bromide led to exclusive formation of the trans addition products (OC-6-43)-[Pt(COMe)₂(R)X(bpy)] (X = I, R = Et, 4b; X = Br, R = CH₂C₆H₅, 4c; CH₂C₆H₄(o-Br), 4d; CH₂C₆H₄(p-COOH), 4e; CH₂-3-py (3-pyridylmethyl), 4f; CH₂-2-tp (2-thiophenylmethyl), 4g; CH₂CH=CH₂, 4h; c-hex-2-enyl (cyclohex-2-enyl), 4i). All complexes 4 were characterized by microanalysis, ¹H and ¹³C NMR and IR spectroscopy. Additionally, complexes 4a, 4f, and 4g were characterized by single-crystal X-ray diffraction analyses. Reactions of 3a and 3b with o-, m- and p-bis(bromomethyl)benzene, respectively, led to the formation of dinuclear platinum(IV) complexes [{Pt(COMe)₂Br(N^N)}₂-{μ-(CH₂)₂C₆H₄}] (5). These complexes were characterized by microanalysis, IR spectroscopy, and depending on their solubility by ¹H and ¹³C NMR spectroscopy, too. A single-crystal X-ray diffraction analysis of complex [{Pt(COMe)₂Br(bpy)}₂{μ-m-(CH₂)₂C₆H₄}] (5b) confirmed its dinuclear composition. The solid-state structures of 4a, 4f, 4g, and 5b are discussed in terms of C–H···O and O–H···O hydrogen bonds as well as π–π stacking between aromatic rings.     

The structures and stability of pentacoordinate germylenoid PhCH<Subscript>2</Subscript>(OH)CH<Subscript>3</Subscript>GeLiF

The structures and stability of pentacoordinate germylenoid PhCH₂(OH)CH₃GeLiF were first theoretically studied by density functional theory. Two equilibrium structures, the three-membered ring (1a) and the p-complex (1b) structures, were located. Their energy are in the order of 1b > 1a. The Ge-O coordination energies at the B3LYP/6-311+G(d, p) level are 13.6 and 0.2 kJ/mol in 1a and 1b, respectively. The insertion reactions with CH₃F indicate that germylenoid PhCH₂(OH)CH₃GeLiF is more stable than germylene PhCH₂(OH)CH₃Ge. The insertion barrier of 1a with CH₃F is only 3.1 kJ/mol higher than that of PhCH₃CH₃GeLiF, indicating that the oxygen coordination PhCH₂(OH)CH₃GeLiF has the same stability as PhCH₃CH₃GeLiF.     

Reactions at the B–B Bond of Bis(trisyl)oxadiborirane: Ring Extensions

The B–B bond of bis(trisyl)oxadiborirane OB₂R₂ (R = C(SiMe₃)₃) is opened by amides R′CO(NHR″) to give the dioxaazadiboracyclohexanes [–BR–O–BR–NR″–CHR′–O–] (R′/R″ = H/H, H/Me, H/Et, Me/H: 5 a – d ). The amide MeCO(NHMe) yields 5 e (R′/R″ = Me/Me), when an excess of the amide is applied for 24 h, but yields an isomeric 1 : 1 adduct ( 6 e ), when a stoichiometric amount of the amide is applied for 15 h; upon refluxing this isomer in hexane, it is transformed into 5 e .