Reaktionen von bis(η-cyclopentadienyl)zirconiumhydriden mit (iminoacyl)zirconocen-komplexen

The reaction of imidoylzirconocene complexes with zirconocene hydrides yields (N-alkylamido)zirconocene complexes. For a mechanistic study, the specifically substituted imidoylzirconocene complexes 3b–3d have been prepared and treated with the oligomeric metal hydrides (Cp₂ZrH₂)_x (1b) and (Cp₂ZrHCl)_x (1c). (N-Benzyl formimidoyl)zirconocene chloride (3b) was obtained by treating 1c with benzyl isonitrile 2a. Treatment of dimethylzirconocene with 2a gave (N-benzyl acetimidoyl)methylzirconocene (3c), which was treated with PhICl₂ to give (N-benzylacetimidoyl)zirconocene chloride (3d). The reaction of 3d with (Cp₂ZrH₂)_x (1b) yielded (N-benzyl-N-ethylamido)zirconocene chloride (4b) as the only identified product. A 1/1 mixture of 4b and methylzirconocene chloride was obtained upon treatment of 3c with (Cp₂ZrHCl)_x (1c); in contrast, the reaction of 1c with 3b gave an equimolar mixture of Cp₂ZrCl₂ and (N-benzyl-N-methylamido)zirconocene chloride (4c). Reaction paths through binuclear (μ-CHR′=NR) zirconocene intermediates are proposed to explain these experimental observations.     

Perfluormethyl-element-liganden : XXXI. Ligandeneigenschaften von Me2PP(CF3)2 und Me2AsP(CF3)2

The coordinating properties of the trifluoromethyl elemental compounds Me₂PP(CF₃)₂ and Me₂AsP(CF₃)₂ have been studied by the synthesis and spectroscopic investigations (IR, NMR, MS) of their complexes cis-M(CO)₄L₂ (A), [(CO)₄ML]₂ (B) and [(CO)₅M]₂L (C) (M = Cr, Mo, W). Complexes of type A with L = Me₂PP(CF₃)₂ are obtained in good yield by reaction with M(CO)₄NBD (NBD = norbornadiene), whereas with L = Me₂AsP(CF₃)₂ the homobinuclear compounds B are formed. The attempt to prepare the cis-M(CO)₄[Me₂AsP(CF₃)₂]₂ complexes by treating M(CO)₄(Me₂AsH)₂ with P₂(CF₃)₄ is successful only for M = W. Binuclear compounds of type B or C, in general, can be prepared by stepwise reaction of the ligands with either M(CO)₄NBD or M(CO)₅THF.     

Profiles of ethylene polymerization with zirconocene–trialkylaluminum/borane compound

Ethylene polymerization was conducted with bis(cyclopentadienyl)zirconium dichloride (1) and rac-dimethylsilylenebis(indenyl)zirconium dichloride (2) combined with trialkylaluminum (AlR₃; R=methyl (Me), ethyl (Et), isobutyl (iBu))/triphenylcarbenium tetrakis(pentafluorophenyl)borate (Ph₃CB(C₆F₅)₄) or tris(pentafluorophenyl)borane (B(C₆F₅)₃) to study the effect of cocatalysts on polymerization rate (R_p). When AlMe₃ was used, no activity or very low activity was observed with both zirconocenes regardless of the borane compounds used. The replacement of AlMe₃ to AlEt₃ or AliBu₃ with 1–AlR₃/Ph₃CB(C₆F₅)₄ caused polymerization and induction time was observed to reach the maximum R_p. Especially in the case of using AlEt₃, it took about 30 min to show the activity. When B(C₆F₅)₃ was used, AlEt₃ was not effective but AliBu₃ gave the highest activity among all the combinations of AlR₃ and the borane compounds. In the case of polymerization with 2 using Ph₃CB(C₆F₅)₄, high activity was observed with both AlEt₃ and AliBu₃ without any induction period. When B(C₆F₅)₃ was used instead of Ph₃CB(C₆F₅)₄, very low activity was observed with AlEt₃. On the other hand, high activity was observed with AliBu₃, and the maximum R_p was found at the beginning of the polymerization. The effect of AlR₃ on the formation of active species was discussed based on these results.     

Alkoxo, chlorido, and methyl derivatives of oxidomolybdenum(VI) complexes with tetradentate [O3N]-type ligands

Dioxomolybdenum(VI) complex [MoO₂(Heg)₂] (H₂eg = 1,2-ethanediol) reacts with phenolic ligand precursors tris(2-hydroxy-3,5-dimethylbenzyl)amine (H₃L^Me) and tris(2-hydroxy-3,5-di-tert-butylbenzyl)amine (H₃L^tBu) to form oxomolybdenum(VI) complexes of type [MoO(L^R) (Heg)]. The Heg ligand can be replaced by other alcohols (i.e. 2-aminoethanol, 2-amino-2-methylpropan-1-ol, 2-(dimethylamino)ethanol or allyl alcohol) in the reaction at refluxing toluene or at neat alcohol. Treatment of [MoO(L^R)(Heg)] with Me₃SiCl yields corresponding chlorido complexes [MoO(L^R)Cl]. These are also formed in the reaction of H₃L^R with [MoO₂Cl₂(dmf)₂]. The reaction of [MoO(L^R)Cl] with MeMgI yields air-stable monomethyl derivatives [MoO(L^R)(Me)]. X-ray analyses of [MoO(L^tBu)X] (X = Heg, 2-methyl-2-aminopropanolate anion or Cl) reveal that the ligand L^R has a tetradentate coordination through three oxygen donors and one nitrogen donor, which is located trans to the terminal oxo group. The sixth coordination site is occupied by an oxygen donor, a chlorido ligand or a methyl group.     

New seven-coordinate thiourea and N,N,N′,N′-tetramethylthiourea complexes of molybdenum(II) and tungsten(II)

The compounds [MI₂(CO)₃(NCMe)₂] (M = Mo or W) react with one equivalent of thiourea (tu) in MeOH or N,N,N′,N′-tetramethylthiourea (tmtu) in CH₂Cl₂ at room temperature to initially afford the monoacetonitrile compounds [MI₂(CO)₃(NCMe)L] (L = tu or tmtu) which rapidly transform to the isolated iodide bridged dimers, [M(μ-I)I(CO)₃L]₂ with loss of acetonitrile. Reaction of [WI₂(CO)₃(NCMe)₂] with two equivalents of tu or tmtu gave the expected mononuclear seven-coordinate compounds [WI₂(CO)₃L₂]. However, reaction of [MoI₂(CO)₃(NCMe)₂] with two equivalents of tu or tmtu rapidly affords the iodide-bridged dimers [Mo(μ-I)I(CO)₂L₂]₂ with loss of carbon monoxide from [MoI₂(CO)₃L₂]. The low temperature (−70°C) ¹³C NMR spectrum of [Mo(μ-I)I(CO)₂ {SC(NMe₂)₂}₂]₂ suggests the complex is based on two capped octahedra with a carbonyl ligand capping each octahedral face.     

Ruthenium(II) complexes with mono and ditertiary arsines and phosphines and their reaction with small molecules

Dichlorotetrakis(dimethylsulphoxide)ruthenium(II) reacts with AsPh₃ AsMePh₂, AsMe₂Ph and SbPh₃ in ethanolic hydrochloric acid solution to yield the complexes RuCl₂(DMSO)₂(AsPh₃)₂, RuCl₂(DMSO) L₂ (L = AsMePh₂, AsMe₂Ph, SbPh₃) respectively. The treatment of ruthenium(II) blue solution with AsMePh₂, AsMe₂Ph and SbPh₃ in alcohol resulted in the formation of the complexes; RuCl₂L₃ (L = AsMePh₂, AsMe₂Ph and SbPh₂), respectively. The reaction of RuCl₂(DMSO)₄ with the bidentate ligands 1,2 bis (diphenylarsino)methane (DPAM), 1,2 bis(diphenylarsino)ethane (DPAE) and 1,2 bis (diphenylphosphino)methane (DPPM). 1,2 bis(diphenylphosphino)ethane (DPPE), in ethanol gave the complexes RuCl₂(DPAM)₂, RuCl₂(DPAE)₂, RuCl₂ (DPPM)₂ RuCl₂(DPPE)₂, respectively. The complexes thus obtained undergo reaction with carbon monoxide, hydrogen, molecular nitrogen and nitric oxide to yield a variety of mixed ligand complexes.     

Supported metallocene catalysts—interactions of (n-BuCp)2HfCl2 with methylaluminoxane and silica

The species on supported olefin polymerisation catalysts consisting of (n-BuCp)₂HfCl₂, methylaluminoxane (MAO) and dehydroxylated silica were identified by EXAFS and UV-Vis spectroscopy. Whereas the reaction of (n-BuCp)₂HfCl₂ with silica leads to a product containing HfO and HfSi non-bonded interactions with concurrent loss of Hf---Cl bonds, the reaction of (n-BuCp)₂HfCl₂ with silica pretreated with methylaluminoxane yields a mixture of several hafnocene species. The bonding features of (n-BuCp)₂HfCl₂ and (n-BuCp)₂HfCl₂/SiO₂ are still present to some extent but with new interactions consistent with hafnocene cation formation. The relative proportions of these species depend strongly on the method of the catalyst preparation.     

Synthesis of novel platinum-silver and platinum-copper complexes with bridging alkynyl ligands

The study of the reactivity of [Pt₂M₄(CCR)₈] (M=Ag or cu; R=Ph or ^tBu) towards different neutral and anionic ligands is reported. This study reveals that reactions of the phenylacetylide derivatives [Pt₂M₄(CCPh)₈] with anionic, X⁻ (X=Cl or Br) or neutral donors (CN^tBu or py) in a molar ratio 1:4 (m/donor ratio 1:1) yield the trinuclear anionic (NBu₄)₂[{Pt(CCPh)₄ (MX)₂] (M=Ag or Cu, X =Cl or Br) or neutral [{Pt(CCPh0₄=sAGL)₂] (L=CN^tBu or py) complexes, respectively. The crystal structure of (NBu₄)₂[{Pt(CCPh)₄}(CuBr)₂](4) shows that the anion is formed by a dianionic Pt(CCPh)₄ fragment and two neutral CuBr units joined through bridging alkynyl ligands. All the alkynyl groups are σ bonded to Pt and η²-coordinated to a Cu atom which have an approximately trigonal-planar geometry. By contrast, similar reactions with [Pt₂M₄(CC^tBu)₈] (molar ratio M/donor 1:1) afford hexanuclear dianionic (NBu₄)₂[Pt₂M₄(CC^tBu)₈X₂] or neutral [Pt₂Ag₄(CC^tBu0₈Py₂]. Only by treatment with a large exces of Br ⁻ (molar ratio M/Br⁻ 1:2) are the trinuclear complexes (NBu₄)₂[{Pt(CC^tBu₄ (MBr)₂] (M=Ag, Cu) obtained. Attempted preparations of analogous complexes with phosphines (L′=PPh₃ or PEt₃) by reactions of [Pt₂M₄(CCR₈] with L′ leads to displacement of alkynyl ligands from platinum and formation of neutral mononuclear complexes [trans-Pt(CCR)₂L′₂].     

Monomeric, dimeric and polymeric [Cp2MoH2] complexes with Ag---S bonds

The reaction of [Cp₂MoH₂] and AgBF₄ with the dithio ligands Na(S₂CPh) and K(S₂COⁱPr) afforded the complexes [(Cp₂MoH₂AgS₂CPh)₂] (1) and [(Cp₂MoH₂AgS₂COⁱPr)₂] (2). Using the monothio ligands Na(SC(O)Ph), K(SC(O)CH₃) and Na(S(NHPh)C=C(CN)₂) the complexes [(Cp₂MoH₂AgSC(O)Ph)₂] (3), [((Cp₂MoH₂)₂(AgSC(O)CH₃)₃)_n] (4) and [(Cp₂MoH₂)₂AgS(NHPh)C=C(CN)₂] (6) were formed. The reaction of thiobenzamide and [(Cp₂MoH₂)₂AgCl] gave the complex [(Cp₂MoH₂Ag(Cl)S(NH₂)CPh)₂] (5). Complexes 1 and 2 have a dimeric structure with the two dithio ligands bridging the two silver atoms. Complex 3 is also a dimer, however, the monothio ligands are coordinated with their single sulphur atoms to the silver atoms. In the polymer 4 the thioacetate ligand has the same bonding mode as in 3. The three-dimensional structure of 4 is built-up of parallel strings. In the dimer 5 the thiobenzamide ligands bind with the sulphur atom to a silver atom each. Complex 6 has a monomeric structure in which the silver atom is coordinated to two [Cp₂MoH₂] ligands and to the sulphur atom of the S(NHPh)C=C(CN)₂ ligand. Compounds 1–6 were characterised analytically and spectroscopically and the structures were determined by single crystal X-ray analyses.     

基于二噻吩并吡咯π桥的窄带隙非富勒烯受体材料在有机太阳能电池中的应用

以不同烷基取代的二噻吩并吡咯(DTP)为π桥,连接吲哒省并二噻吩(IDT)中间单元和氰基茚酮(IC)或二氟代氰基茚酮(2F-IC)末端基团,设计并合成了6个窄带隙的非富勒烯受体材料。 其中,IDTDTP-C₂C₂-H和IDTDTP-C₂C₂-F中的DTP单元以1-乙基丙基为侧链,IDTDTP-C₆C₆-H和IDTDTP-C₆C₆-F中的DTP单元以1-己基庚基为侧链,IDTDTP-C₁₂-H和IDTDTP-C₁₂-F中的DTP单元以十二烷基为侧链。 6个分子均具有较窄的光学带隙(1.37~1.44 eV)。 相比于以IC为末端基团的分子(IDTDTP-C₂C₂-H、IDTDTP-C₆C₆-H和IDTDTP-C₁₂-H),由于氟原子的拉电子效应,以2F-IC为末端基团的分子(IDTDTP-C₂C₂-F、IDTDTP-C₆C₆-F和IDTDTP-C₁₂-F)具有红移的吸收光谱,以及更低的最高分子占有轨道能级(HOMO)和最低分子空轨道(LUMO)能级。 以宽带隙聚合物聚[2,6-(4,8-双(5-(2-乙基己基))噻吩-2-基)-苯并[1,2-b:4,5-b']二噻吩-alt-5,5-(1',3'-二-2-噻吩)-5',7'-双(2-乙基己基)-苯并[1',2'-c:4',5'-c']二噻吩-4,8-二酮](PBDB-T)为给体材料,制备了有机太阳能电池器件。 PBDB-T:IDTDTP-C₆C₆-F共混薄膜具有较高且更平衡的空穴/电子迁移率,以及良好的形貌,基于PBDB-T:IDTDTP-C₆C₆-F的有机太阳能电池获得了6.94%的能量转换效率,开路电压为0.86 V,短路电流密度为13.56 mA/cm²,填充因子为59.5%。     

The organic ligands as template: the synthesis, structures and properties of a series of the layered structure rare-earth coordination polymers

A series of new 2D-layered structural rare-earth coordination polymers with the general formal [Ln(C₈H₄O₅)(H₂O)₅]·(H₂O)·(C₈H₄O₅)_1/2 (Ln=Eu for (1); Gd for (2); Tb for (3); Dy for (4); and Er for (5)) have been yielded by hydrothermal synthesis. The coordination polymers crystallize in monoclinic space group C/2c with a=19.838(16), b=10.529(8), c=17.752(14) Å, β=107.503(14)° for (1), with a=19.823(7), b=10.552(4), c=17.762(6) Å, β=107.443(6)° for (2), with a=19.770(4), b=10.519(2), c=17.698(4) Å, β=107.52(3)° for (3), with a=19.632(2), b=10.492(2), c=17.617(3) Å, β=107.470(12)° for (4), with a=19.648(7), b=10.480(3), c=17.598(6) Å, β=107.502(6)° for (5), respectively. And the metal ions (Ln³⁺) are located in nine-member coordination environment. The carboxyl groups from 5-hydroxyisophthalate chelate the metal ions to form 1D helical cation chains. It is interesting that these helical cation chains are arranged to form 2D anion–cation layers by the uncoordinated ligands' anions as template. And the luminescence properties of the rare-earth ions are studied in the paper.     

Homochiral cyclopentane-based C1-symmetric P,P ligands C5H8(PPh2)(PR2) from C2-symmetric C5H8(PCl2)2

Treatment of 1,2-trans-C₅H₈(PCl₂)₂ with 1,2-C₂H₄(NHPr-i)₂ gave the C₂-symmetric perhydro-1,6,2,5-diazaphosphocine C₅H₈{P(Cl)N(Pr-i)CH₂}₂-cyclo, which produced dissymmetric C₅H₈(PPh₂){P[N(Pr-i)CH₂]₂-cyclo} on further reaction with PhMgBr. Cleavage of the P---N bonds with gaseous HCl afforded C₅H₈(PPh₂)(PCl₂), which was converted to C₅H₈(PPh₂){P(OPh)₂}₂ by reaction with phenol. All chiral P,P derivatives were obtained as racemates as well as resolved (1R,2R)- and (1S,2S)-enantiomers.     

Synthesis and crystal structures of (C8h8)Nd(C5H9C5H4) (THF)2 and [(C8H8)Gd(C5H9C4H4(THF)][(C8H8)GD(C5H9C5H4(THF)2]

LnCl₃ (Ln=Nd, Gd) reacts with C₅H₉C₅H₄Na (or K₂C₈H₈) in THF (C₅H₉C₅H₄ = cyclopentylcyclopentadienyl) in the ratio of 1 : to give (C₅H₉C₅H₄)LnCl₂(THF)_n (orC₈H₈)LnCl₂(THF)_n], which further reacts with K₂C₈H₈ (or C₅H₉C₅H₄Na) in THF to form the litle complexes. If Ln=Nd the complex (C₈H₈)Nd(C₅H₉C₅H₄)(THF)₂ (a) was obtained: when Ln=Gd the 1 : 1 complex [(C₈H₈)Gd(C_%H₉)(THF)][(C₈H₈)Gd(C₅H₉H₄)(THF)₂] (b) was obtained in crystalline form.

The crystal structure analysis shows that in (C₈H₈)Ln(C₅H₉C₅H₄)(THF)₂ (Ln=Nd or Gd), the Cyclopentylcyclopentadieny (η⁵), cyclooctatetraenyl (η⁸) and two oxygen atoms from THF are coordinated to Nd³⁺ (or Gd³⁺) with coordination number 10.

The centroid of the cyclopentadienyl ring (Cp′) in C₅H₉C₅H₄ group, cyclooctatetraenyl centroid (COTL) and two oxygens (THF) form a twisted tetrahedron around Nd³⁺ (or Gd³⁺). In (C₈H₈)Gd(C₅H₉C₅H₄)(THF), the cyclopentyl-cyclopentadienyl (η⁵), cyclooctatetraenyl (η⁸) and one oxygen atom are coordinated to Gd³⁺ with the coordination number of 9 and Cp′, COT and oxygen atom form a triangular plane around Gd³⁺, which is almost in the plane (dev. -0.0144 Å).     

Structural characteristics of pyrocarbon-fumed silica

Two series of pyrocarbon/fumed silica (CS) samples at different carbon concentrations C_C=0.5–64 wt.% (first series, CSI) and 2.6–53 wt.% (second series, CSII) synthesised by means of pyrolysis of CH₂Cl₂ at fumed silica substrate (S_BET=297 (CSI) and 232 (CSII) m² g⁻¹) under slightly different conditions were studied by using TEM, FTIR-PAS, DTG, and nitrogen adsorption–desorption methods. On methylene chloride carbonisation, disordered carbon deposits can form mainly in the inter-particle volume of secondary particles (aggregates of primary particles and agglomerates of aggregates) covering the surfaces of primary silica particles; therefore, marked reduction of the pore (gaps between primary particles) volume and the specific surface area is observed with increasing C_C. Estimation of distributions of the pore f_SCD(R_p) and particle f(a) sizes using a self-consistent method with binary regularisation with respect to both f_SCD(R_p) and f(a) shows that the average size of particles increases (silica particles are covered by pyrocarbon) and individual pyrocarbon particles (up to 50 nm according to TEM) also appear. Structural parameters of carbosils are characterised by nonlinear changes with increasing carbonisation time. Surface functionalities on CS samples correspond to aromatic and twinned CC bonds with contribution of oxygen-containing groups.     

Preparation and characterization of M2(SeAr′)6 and mixed ligand M2(OR)2(SeAr′)4 species (M = Mo, W)

Toluene solutions of M₂(NMe₂)₆ (M = Mo, W) react with mesitylene selenol (Ar′SeH) to give M₂(SeAr′) ₆ complexes. MO₂(OR)₆ (R = ^tBu, CH₂^tBu) react with excess> 6 fold) Ar′SeH to give Mo₂ (SeAr′)₆, whilst W₂(OR)₆(py)₂ (R = ⁱPr, CH₂^tBu) react with excess (> 6 fold) Ar′SeH to give W₂(OR)₂(SeAr′)₄. Reaction of MO₂(OPrⁱ)₆ with Ar′SeH produces Mo₂(OPrⁱ)₂ (SeAr′)₄ which crystallizes in two different space groups. These areneselenato complexes are air-stable and insoluble in common organic solvents. X-ray crystallographic studies revealed that the Mo₂(SeAr′)₆ and W₂(SeAr′)₆ compounds are isostructural in the solid state and adopt ethane-like staggered configurations with the following important structural parameters, M---M (W---W/Mo---Mo) 2.3000(11)/2.2175(13) Å, M---Se 2.430 (av.)/2.440 (av.) Å, M---M---SE 97.0° (av.)°. In the solid state W₂(OⁱPr)₂(SeAr′)₄ adopts the anti-configuration with crystallographically imposed C_i symmetry and W---W 2.3077(7) Å, W---Se 2.435 (av.) Å, W---O 1.858(6) Å; W---W---SE 100.27(3)°, 93.8(3)° and W---W---O 108.41(17)°. Mo₂(OPrⁱ)₂(SeAr′) ₄ crystallizes in both P and A2/a space groups in which the molecules are isostructural with each other and the tungsten analogue. Important bond lengths and angles are Mo---Mo 2.180(24) Å, Mo---Se 2.432(av.) Å, Mo---O 1.872(9) Å, Mo---Mo---Se 99.39(9)°, 94.71(8)°, Mo---Mo---O 107.55(28)°.     

The chemistry of 1,3,5-triazacyclohexane complexes 5: cationic zinc(II) alkyl complexes of N-alkylated 1,3,5-triazacyclohexanes and 13-benzyl-1,5,9-triazatricyclo[7.3.1.0]-tridecane

Diethylzinc reacts with hydroperchlorates of N-alkylated 1,3,5-triazacyclohexanes (R₃TAC; R = methyl (Me), benzyl (Bz), isopropyl (ⁱPr)) and with the hydrotetrafluoroborate of 1,3,5-tris-(para-fluorobenzyl)-1,3,5-triazacyclohexane (FBz₃TAC) to give the corresponding cationic zinc ethyl complexes [(R₃TAC)Zn(Et)][X] (X = ClO₄⁻, BF₄⁻). Similar complexes were obtained from diethylzinc treated with [HNMe₂Ph][BF₄] or [HNMe₂Ph][B(C₆F₅)₄](Et₂O) in the presence of R₃TAC (R = Bz, FBz, s-1-phenylethyl (s-PhMeCH)). A product of decomposition of [(Bz₃TAC)Zn(Et)][ClO₄] was analyzed by X-ray diffraction. The structures of [({s-PhMeCH}₃TAC)Zn(Et)][BF₄] an [(FBz₃TAC)Zn(Et)][BF₄] were estimated using nuclear Overhauser enhancement spectroscopy. Protonolysis of diethylzinc with [HNMe₂Ph][BF₄] in the presence of 13-benzyl-1,5,9-triazatricyclo[7.3.1.0^5,13]-tridecane (BzTATC) yielded the complex [(BzTATC)Zn(Et)][BF₄].     

ansa-Metallocene derivatives XXXIII. 2-Dimethylamino-substituted bis-indenyl zirconium dichloride complexes with and without a dimethylsilyl bridge: syntheses, crystal structures and properties in propene polymerization catalysis

Bis(2-N,N-dimethylamino-indenyl) zirconium dichloride, (2-(CH₃)₂N-C₉H₆)₂ZrCl₂, and dimethylsilyl-bridged bis(2-N,N-dimethylamino-indenyl) zirconium dichloride, (CH₃)₂Si(2-(CH₃)₂N-C₉H₅)₂ZrCl₂, were prepared by reaction of the corresponding ligand lithium salts with ZrCl₄ in toluene. Diffractometric structure determinations reveal C₂-symmetric complex geometries for both complexes. An increased electron density at the Zr center of the dimethylamino-substituted complexes is indicated by reduction potentials which are 0.3–0.4 V more negative than those of their unsubstituted analogs. When activated with methyl aluminoxane in toluene solution, (CH₃)₂Si(2-(CH₃)₂N-C₉H₅)₂ZrCl₂ catalyzes the polymerization of propene to polymers with a microstructure comparable with that of polymers produced with other Me₂Si-bridged bis(indenyl)ZrCl₂ complexes, but with a substantially increased fraction of i-propyl end groups derived from alkyl exchange between Zr-polymer and Al---Me species.     

Reaction of silylpentacarbonylmanganese with hydride-transfer reagents: reduction of carbonyl ligands accompanied with Si---C and C---C coupling

Treatment of Mn(CO)₅SiTol^p₂H (2) with an excess of LiAlH₄, NaBH₄, or NaBH₃(CN) in THF at room temperature gave hydrosilane H---SiTol^p₂H in high yield together with Mn₂(CO)₁₀. No reduction of CO ligands was observed. On the other hand, treatment of 2 with an excess of Red-Al (=Na[(CH₃OCH₂CH₂O)₂AlH₂]) in toluene and subsequent addition of aqueous acidic solution afforded alkylsilanols (CH₃)SiTol^p₂(OH) and (C₂H₅)SiTol^p₂(OH). Treatment of the reaction mixture of 2 and Red-Al with LiAlH₄ in diethyl ether instead of hydrolysis gave alkylhydrosilanes (CH₃)SiTol^p₂H and (C₂H₅)SiTol^p₂H. The methyl and ethyl groups on silicon originate from the CO ligands in 2. These products clearly demonstrate that not only the Si---C coupling, but also C---C coupling occurs efficiently in this reaction.     

Another example of carborane based trianionic ligand: Syntheses and catalytic activities of cyclohexylamino tailed ortho-carboranyl zirconium and titanium dicarbollides

In situ reaction of Li[closo-1-Ph-1,2-C₂B₁₀H₁₀] with 7-azabicyclo [4.1.0] heptane results in the formation of the disubstituted carborane, closo-1-Ph-2-(2′-aminocyclohexyl)-1,2-C₂B₁₀H₁₀ (1), in 63% yield. Decapitation of (1) with potassium hydroxide in refluxing ethanol produces the cage-opened nido-carborane, K[nido-7-Ph-8-(2′-aminocyclohexyl)-7,8-C₂B₉H₁₀]⁻ (2), in 80% yield. Deprotonation of the above monoanion with two equivalents of n-butyllithium followed by reaction with anhydrous MCl₄ · 2THF (M = Zr, Ti) provides d⁰-half-sandwich metallocarboranes, closo-1-M(Cl)-2-Ph-3-(2′-σ-(H)N-cyclohexyl)-2,3-η⁵-C₂B₉H₉ (3 M = Zr; 4 M = Ti) in 53% and 42% yields, respectively. The reaction of Li[closo-1,2-C₂B₁₀H₁₁] with 7-azabicyclo [4.1.0] heptane in THF affords closo-1-(2′-aminocyclohexyl)-1,2-C₂B₁₀H₁₀ (5) in 59% yield. Immobilization of the carboranyl amino ligand (1) to an organic support, Merrifield’s peptide resin (1%), has been achieved by the reaction of the sodium salt of (5) with polystyryl chloride in THF to produce closo-1-(2′-aminocyclohexyl)-2-polystyryl-1,2-C₂B₁₀H₁₀ (6) in 87% yield. Further reaction of the dianion derived from (6) with anhydrous ZrCl₄ · 2THF led to the formation of the organic polystyryl supported d⁰-half-sandwich metallocarborane, closo-1-Zr(Cl)-2-(2′-σ-(H)N-cyclohexyl)-3-polystyryl-2,3-η⁵-C₂B₉H₉ (7), in 38% yield. These new compounds have been characterized by elemental analyses, NMR, and IR spectra. Polymerizations of both ethylene and vinyl chloride with (3) and (7) have been performed in toluene using MMAO-7 (13% ISOPAR-E) as the co-catalyst. Molecular weights up to 32.8 × 10³ (M_w/M_n = 1.8) and 9.5 × 10³ (M_w/M_n = 2.1) were obtained for PE and PVC, respectively.     

Zur reaktion von metall-koordiniertem kohlenmonoxid mit yliden : XX. “Ylidreaktionen” einfacher dicarbonyl(pentamethylcyclopentadienyl)rutheniumkomplexe

Treatment of the dimer complex [C₅Me₅ (CO)₂ Ru]₂ (1) with HBF₄ in CH₂Cl₂ at room temperature yields the hydrido-bridged dinuclear complex [(C₅Me₅)₂Ru₂(CO)₄H]BF₄ (2), and after refluxing in propionic anhydride [C₅Me₅(CO)₃Ru]BF₄ (5) is obtained, UV-irradiation of 1 in the presence of H₂CHal₂ (Hal = Cl, I) or trimethylphosphine leads to the formation of C₅Me₅(CO)₂Ru-Hal (3a, 3b) or C₅Me₅(CO)(Me₃P)RuH (4) respectively. Exchange reactions of 3a, 3b with LiAlH₄, NaOMe and Me₃ P give the complexes C₅Me₅(CO)₂RuX (6a,6b) (X=H, OMe), C₅Me₅(CO)(Me₃P)Ru-Hal (7a,7b) (Hal = Cl, I) and C₅Me₅(Me₃P)₂RuI (8). The interaction of 3b or 5 with Me₃P=CH₂ leads to the formation of the ylide complex [C₅Me₅(CO)(Me₃P)-RuCH₂PMe₃)Cl (9) or the rutheniumacyl-ylide C₅Me₅(CO)₂RuC(O)CH=PMe₃ (10). 4 reacts with Me₃P=CH₂ to give C₅Me₅(CO)(Me₃P)RuMe (11) and Me₃P via the intermediate formation of the phosphonium salt Me₄P[Ru(CO) (Me₃P)-C₅Me₅].