New telechelic polymers and sequential copolymers by polyfunctional initiator-transfer agents (inifers). II. Synthesis and characterization of α,ω-di(tert-chloro)polyisobutylenes

Detailed understanding of the mechanism of initiation and chain transfer in BCl₃-coinitiated isobutylene polymerization led to the efficient synthesis of symmetric telechelic polyisobutylenes carrying ～CH₂C(CH₃)₂Cl groups at either end of the molecule Cl-PIB-Cl. The synthesis is based on the use of inifers, i.e., bifunctional initiator-transfer agents that effect controlled initiation and propagation in the absence of chain transfer to a monomer. Specifically, the synthesis of Cl-PIB-Cl was achieved by the p-dicumyl chloride/BCl₃/isobutylene/CH₂Cl₂ system. According to the inifer mechanism each Cl-PIB-Cl contains two terminal tertiary chlorines and one phenyl group at the interior of the chains. The structure of this new symmetric telechelic polymer has been established by detailed characterization studies including a sensitive new gel permeation chromatography (UV plus RI) analysis method, ¹H-NMR, kinetic experiments, and chemical derivatization. The Cl-PIB-Cl molecule is a key intermediate for the synthesis of hosts of new materials, e.g., triblock copolymers, α,ω-diolefins, and α,ω-difunctional polymers.     

Poly(β-pinenes) carrying one,two, and three functional end groups. II. Syntheses and characterization

Conditions for the convenient synthesis of linear poly(β-pinenes) that carry one or two tert-chloro end groups (～Cl^t) and three-arm star poly(β-pinenes) that carry three termini have been worked out. Specifically, the polymer with one ～Cl^t end group was prepared by the H₂O/BCl₃ system, whereas those with two and three ～Cl^t termini were prepared by the use of p-dicumyl chloride and sym-tricumyl chloride/BCl₃ inifer combinations. The ～Cl^t-terminated polymers were dehydro-chlorinated to yield the corresponding olefins. The molecular weights of the products were low enough to permit infrared (IR) and quantitative ¹H-NMR investigations. Poly(β-pinene-b-tetrahydrofuran) diblock copolymers have been synthesized by inducing the polymerization of tetrahydrofuran (THF) by the Pβ? Cl^t/AgCF₃SO₃ initiating system.     

Living carbocationic polymerization of p-halostyrenes. III. Syntheses and characterization of novel thermoplastic elastomers of isobutylene and p-chlorostyrene

Novel linear and three-arm star radial thermoplastic elastomers (TPE) comprising rubbery polyisobutylene (PIB) center blocks connected to glassy poly(p-chlorostyrene) (PpClSt) outer blocks have been synthesized by sequential monomer addition. For triblock polymer synthesis isobutylene (IB) was added continuously to a bifunctional initiating system (dicumylmethyl ether/TiCl₄) dissolved in CH₃Cl/methylcyclohexane solvent mixture at –80°C. After the living PIB sequence has reached the desired molecular weight p-chlorostyrene (pClSt) was added to produce the PpClSt end blocks. The synthesis conditions for the TPEs were developed with the help of model experiments using the 2-chloro-2,4,4-trimethylpentane (TMPCl)/TiCl₄ initiating system and subsequent PIB-PpClSt diblock syntheses. The triblock and radiol block polymers after solvent extraction exhibited excellent TPE characteristics. Copolymer compositions were determined by ¹H-NMR and UV spectroscopy and further characterization was carried out by GPC, DSC, DMTA, and selective solvent extraction techniques. The TPEs exhibit two T_g's characteristic of glassy PpClSt (129°C) and rubbery PIB (?70°C) segments. Cast TPE films were clear and gave tensile strengths of 1.2-21 MPa with elongations of 460–1500%. Transmission electron microscopy (TEM) of a triblock polymer containing ca. 38 wt % PpClSt suggests cylindrical PpClSt domains of 40–70 nm length and 25–35 nm diam embedded in a PIB matrix.     

Poly(β-pinenes) carrying one,two, or three functional end groups. I. The effect of reaction conditions on the polymerization of β-pinene

β-Pinene was polymerized with H₂O/BCl₃ (protic) and p-dicumyl chloride and sym-tricumyl chloride (nonprotic) inifer systems in CH₂Cl₂ or CH₂Cl₂/n-C₆H₁₄ solvents from ?10 to ?70°C. The effect of solvent polarity, temperature, and monomer and inifer concentration on conversions and molecular weights was investigated. Low conversions and molecular weights, M?_n = 1300–2500, obtained under these conditions suggest rapid termination.     

Secondary interactions in n‐(chloromethyl)pyridinium chlorides (n = 2, 3, 4)

In the isomeric title compounds, viz. 2‐, 3‐ and 4‐(chloro­methyl)pyridinium chloride, C₆H₇ClN⁺·Cl^?, the secondary interactions have been established as follows. Classical N—H?Cl^? hydrogen bonds are observed in the 2‐ and 3‐isomers, whereas the 4‐isomer forms inversion‐symmetric N—H(?Cl^??)₂H—N dimers involving three‐centre hydrogen bonds. Short Cl?Cl contacts are formed in both the 2‐isomer (C—Cl?Cl^?, approximately linear at the central Cl) and the 4‐isomer (C—Cl?Cl—C, angles at Cl of ca 75°). Additionally, each compound displays contacts of the form C—H?Cl, mainly to the Cl^? anion. The net effect is to create either a layer structure (3‐isomer) or a three‐dimensional packing with easily identifiable layer substructures (2‐ and 4‐isomers).     

Darstellung und Schwingungsspektren von trans-[Pt(acac)2X2] (X  Cl,Br, I,SCN, SeCN,N3)

Preparation and Vibrational Spectra of trans-[Pt(acac)₂X₂] (X ? Cl, Br, I, SCN, SeCN, N₃) By electrolytical oxidation of [Pt(acac)₂] in presence of chloride or bromide, dissolved in dichlormethane, trans-[Pt(acac)₂X₂], X ? Cl, Br, are formed. On treatment of trans-[Pt(acac)₂I₂] with silver pseudohalides trans-[Pt(acac)₂X₂], X ? SCN, SeCN, N₃, are obtained. Beside the nearly persistent bands of coordinated acetylacetonate in the Raman spectra the intensive and sharp symmetric, in the IR spectra the corresponding antisymmetric stretching vibration of the X? Pt? X axis is observed. The observance of the rule of mutual exclusion proves the complexes to belong to point group D_2h. From the resonance Raman spectrum of trans-[Pt(acac)₂I₂] for v_s (Pt? I), A_g, the harmonic frequency ω₁ = 142.45 cm^?1 and the inharmonicity constant x₁₁ = 0.48 cm^?1 is calculated. In the Raman spectrum of trans-[Pt(acac)₂Cl₂] v_s (Pt? Cl) is splitted by the isotops ³⁵Cl/³⁷Cl into the triplet 340, 335, 330 cm^?1 giving the force constant f_PtCl = 2.01 N/cm.     

NMR and kinetic studies of the interactions of [Au(cis-DACH)Cl2]Cl and [Au(cis-DACH)2]Cl3 with potassium cyanide in aqueous solution

The interactions of [Au(cis-DACH)Cl₂]Cl and [Au(cis-DACH)₂]Cl₃ [where cis-DACH is cis-1,2-diaminocyclohexane] with enriched KCN were carried out in CD₃OD and D₂O, respectively. The reaction pathways of these complexes were studied by ¹H, ¹³C, ¹⁵N NMR, UV spectrophotometry, and electrochemistry. The kinetic data for the reaction of cyanide with [Au(cis-DACH)₂]Cl₃ are k = 18 M^?1s^?1, ?H^≠ = 11 kJ M^?1, ?S^≠ = ?185 JK^?1 M^?1, and E_a = 13 kJ M^?1 with square wave voltammetric (SWV) peak +1.35 V, whereas the kinetic data for the reaction of cyanide ion with [Au(cis-DACH)Cl₂]Cl are k = 148 M^?1s^?1, ?H^≠ = 39 kJM^?1, ?S^≠ = ?80 JK^-1 M^?1, and E_a = 42 kJM^?1 along with SWV peak +0.82 V, indicating much higher reactivity of [Au(cis-DACH)Cl₂]Cl toward cyanide than [Au(cis-DACH)₂]Cl₃. The interaction of these complexes with potassium cyanide resulted in an unstable [Au(¹³CN)₄]^? species which readily underwent reductive elimination reaction to generate [Au(¹³CN)₂]^? and cyanogen.     

Copper (I) 1,3-R2-3,4,5,6-tetrahydropyrimidin-2-ylidenes (R=mesityl, 2-propyl): synthesis, X-ray structures, immobilization and catalytic activity

The synthesis of novel copper (I) N-heterocyclic carbene complexes is described. Thus, reaction of CuX with 1,3-di(2-propyl)-3,4,5,6-tetrahydropyrimidin-2-ylidene yields CuX(1,3-di(2-propyl)-3,4,5,6-tetrahydropyrimidin-2-ylidene) (X=Cl, (1a), Br (1b)); however, reaction of CuCl with 1,3-dimesityl-3,4,5,6-tetrahydropyrimidin-2-ylidene yields the bis-N-heterocylcic carbene complex Cu(1,3-dimesityl-3,4,5,6-tetrahydropyrimidin-2-ylidene)₂⁺CuBr₂⁻ (2). A supported version of 1, i.e. PS-DVB-CH₂-OCO-CF₂-CF₂-CF₂-COOCu(1,3-di(2-propyl)-3,4,5,6-tetrahydropyrimidin-2-ylidene) (3) was prepared from 1 and PS-DVB-CH₂-OCO-CF₂-CF₂-CF₂-COOAg. A copper loading of 4.15 μmol/g was realized. The new compounds were used as catalysts in carbonyl hydrosilylation and cyanosilylation reactions. Excellent reactivity was observed, giving raise to turn-over numbers (TONs) of up to 100,000. Compounds 1a, 1b, and 2 have also been used as catalysts for the atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA). A linear conversion of monomer with time was observed, however, no control over molecular weight of PMMA was observed.     

Electrophilic substitution of organosilicon compounds. II. Synthesis of allyl-terminated polyisobutylenes by quantitative allylation of tert-chloro-polyisobutylenes with allyltrimethylsilane

Essentially quantitative allylation of linear and three-arm star tert-chloro capped polyisobutylenes [^tCl–PIB–Cl^t and PIB(Cl^t)₃] has been achieved by the use of allyltrimethylsilane (AllylSiMe₃) and Friedel–Crafts acids. Quantitative allylation occurs under suitable conditions, e.g., slight molar excess of TiCl₄ and AllySiMe₃ polar media, ?70°C. These conditions have been developed from quantitative model allylation experiments using 2,4,4-trimethyl-2-chloropentane. Essentially quantitative allylation occurs with long-chain or “once fired” tert-chloro-end groups. Complete allylation can also be effected in a “one-pot two-step” synthesis, i.e., by first preparing the tert-chloro-ended PIB by the inifer method and without isolating the product, completing the synthesis by allylation in the same reactor. Extensive but not quantitative allylation can also be obtained in situ, i. e., during polymerization, by the use of the AllylSiMe₃/cumyl chloride/BCI₃/isobutylene combination. While allylation proceeds with great ease under the mildest conditions, e.g., ?70°C, vinylation with vinyltrimethylsilane could not be achieved even under more forcing conditions.     

Tetrakis(chloromethyl)phosphonium chloride monohydrate

Tetrakis­(chloro­methyl)­phospho­nium chloride monohydrate, C₄H₈Cl₄P⁺·Cl^?·H₂O or P(CH₂Cl)₄⁺·Cl^?·H₂O, is the first crystal structure determination of a tetrakis­(halogeno­methyl)­phospho­nium compound to date. The only comparable structures known so far are of phospho­nium ions containing just one halogeno­methyl group. The solvent water mol­ecule interacts with the Cl^? anion via hydrogen bonds, with O?Cl distances of 3.230 (2) and 3.309 (2) Å. The structure also contains several C—H?Cl^? and C—H?O contacts, though with longer D?A distances [D?A 3.286 (3)–3.662 (2) Å] or bent D—H?A angles. For these reasons, the C—H?Cl^? and C—H?O interactions should not be considered as strong hydrogen bonds.     

trans‐Di­chloro­tetrakis(4‐methylpyrimidine‐N1)­ruthenium(II)

The title compound, trans‐[Ru^IICl₂(N¹‐mepym)₄] (mepym is 4‐methylpyrimidine, C₅H₆N₂), obtained from the reaction of trans,cis,cis‐[Ru^IICl₂(N¹‐mepym)₂(SbPh₃)₂] (Ph is phenyl) with excess mepym in ethanol, has fourfold crystallographic symmetry and has the four pyrimidine bases coordinated through N¹ and arranged in a propeller‐like orientation. The Ru—N and Ru—Cl bond distances are 2.082 (2) and 2.400 (4) Å, respectively. The methyl group, and the N³ and Cl atoms are involved in intermolecular C—H?N and C—­H?Cl hydrogen‐bond interactions.     

Chlorination of Two Isomers of C86 Fullerene: Molecular Structures of C86(16)Cl16, C86(17)Cl18, C86(17)Cl20, and C86(17)Cl22

Chlorination of a mixture of C₈₆ isomers no. 16 (C_s) and no. 17 (C₂) with VCl₄ or a (TiCl₄+Br₂) mixture afforded crystalline chlorides with 16 to 22 Cl atoms per fullerene cage. Single crystal X‐ray diffraction with the use of synchrotron radiation enabled us to determine the chlorination patterns of C₈₆(16)Cl₁₆, C₈₆(17)Cl₁₈, C₈₆(17)Cl₂₀, and C₈₆(17)Cl₂₂. At these degrees of chlorination, addition patterns of C₈₆(16) and C₈₆(17) chlorides have some features in common, owing to the close similarity in the cage structures of both isomers. The average energy of C?Cl bonds decreases with increasing number of attached Cl atoms.     

Heterobinuclear and Heterotrinuclear complexes of Oxorhenium(V) with Cu(II), Ni(II), Fe(III), UO2(VI) and Th(IV) in the solid state

New heteronuclear complexes containing oxorhenium(V), Cu(II), Ni(II), Fe(III), UO₂(VI) and Th(IV) ions were prepared by the reaction of the complex ligand, [ReO(H₄L)Cl]Cl₂, where H₄L = 8,17-dimethyl-6,15-dioxo-5,7,14,16-tetrahydrodibenzo[a,h][14]annulene-2,11-dicarboxylic acid, with the previous transition and actinide salts. Three heteronuclear Cu(II) complexes were isolated depending on the ratio of [ReO(H₄L)Cl]Cl₂?:?Cu(II) ion. When the ratios were 1?:?0.5, 1?:?1 and 1?:?2, the heteronuclear complexes {[ReO(H₃L)Cl]₂CuCl₂(OH₂)₂}SO₄ · H₂O (I), [ReO(H₃L)Cl₂Cu(OH₂)₂(SO₄)] (II) and {ReO(H₂L)Cl[Cu(OH₂)₃ SO₄]₂} (III) were obtained, respectively. Heteronuclear complexes of the other metal cations were obtained by mixing [ReO(H₄L)Cl]Cl₂ with the metal salt in the ratio 1?:?1 to obtain the heteronuclear complexes [ReO(H₃L)Cl₂Ni(OH₂)₂](NO₃)₂ (IV), [ReO(H₃L)Cl₃Fe(OH₂)₃](NO₃)₂ (V), [ReO(H₃L)ClUO₂(NO₃)₂ (OH₂)]Cl (VI) and [ReO(H₃L)Cl₃Th(NO₃)₂(OH₂)]NO₃ · 2H₂O (VII). The complex ligand coordinates with the heterometal ion via the carboxylate group, and the infrared bands ν_as COO and ν_s COO indicate that the carboxylate acts as a unidentate ligand to the heterometal cations. Cu(II) and Fe(III) cations in the heteronuclear complexes have octahedral geometry, while Ni(II) is square planar. Thermal studies explored the possibility of obtaining new heteronuclear complexes pyrolytically in the solid state from the corresponding mother complexes. The structures of the complexes were elucidated by conductance, IR and electronic spectra, magnetic moments, ¹H NMR and TG-DSC measurements as well as by mass spectroscopy.     

Kristall- und Molekülstruktur von fac-Trichloro-tris(dimethylsulfoxid)bismut(III) BiCl3(DMSO)3

Crystal and Molecular Structure of fac-Trichloro-tris(dimethyl sulfoxide)bismuth(III) BiCl₃(DMSO)₃ Crystals of the known, although structurally not characterized title compound were fortuitously obtained from a reaction mixture containing (CH₃)₃SiN(SO₂CH₃)₂, BiCl₃, DMSO, CH₂Cl₂ and CH₃NO₂. Crystallographic data (at ?130°C): triclinic, space group P1 1, a = 816.1(5), b = 885.1(6), c = 1 360.6(8) pm, α = 77.58(3), β = 77.39(3), γ = 64.42(3)°, U = 0.8569 nm³, Z = 2. The DMSO ligands are bound through oxygen to the Bi atom. Important bond distances and angles in the resulting fac-octahedral complex are as follows: Bi? Cl 258.9, 261.0, 263.0, Bi? O 242.6, 245.7, 246.1 pm; Cl? Bi? O (trans) 170.3, 170.6, 176.9, Cl? Bi? Cl 94.6, 94.7, 96.0, O? Bi? O 81.7, 85.4, 87.9, Cl? Bi? O (cis) in the range 87.2–92.6, Bi? O? S 123.4, 126.1, 129.6°.     

Bis(2,2‐bi­pyridine‐N,N′)tetra‐μ‐chloro‐tetracopper(I)

A novel centrosymmetric chair‐like dimer, bis(2,2′‐bi­pyridine)‐1κ²N,N′;3κ²N,N′‐tetra‐μ‐chloro‐1:2κ²Cl;­2:3κ²Cl;­3:4κ²Cl;1:4κ²Cl‐tetra­copper(I), [Cu₄Cl₄­(C₁₀­H₈­N₂)₂], has been solvothermally synthesized and structurally characterized. The complex self‐assembles into a three‐dimensional network via C—H?Cl hydrogen bonds, π–π stacking and weak Cu?Cl electrostatic interactions.     

Bis[1,1′‐bis(diphenylphosphino)ferrocenium] hexadecachlorotetraantimony(III) ethanol solvate

In the title compound, [Fe(C₁₇H₁₄P)₂]₂[Sb₄Cl₁₆]·C₂H₆O, the Fe atoms lie on inversion centres and the pairs of cyclopentadienyl rings are consequently in a fully staggered conformation. The centrosymmetric anionic clusters formed by [Sb₄Cl₁₆]^4? are surrounded by the cations and are held together by weak C—H?Cl interactions. These formations stack along the a axis to form columns, and the columns are interconnected by another weak C—H?Cl interaction along the b axis.     

Rh(III), Pd(II), Pt(IV) and Au(III) complexes of 2-thiopyrimidine derivatives

Some news thiopyrimidine derivatives and complexes [4-amino-5-nitroso-6-oxo-1,2,3,6-tetrahydro-2-thio-pyrimidine (TANH), its 2-methylthio derivative (MTH), the ammonium salt ofTANH (sTANH) and six new complexes of formulas: Rh(MT)₂Cl · 2H₂O, Pd(MTH)₂Cl₂, Pt(MTH)₂Cl₄, Au(MTH)Cl₃ Pd(TANH)₂Cl₂ and Au(TAN ^–)Cl] have been synthesized and characterized by elemental analysis, IR and¹H-NMR spectroscopy techniques. The thermal behaviour of all compounds has also been studied.

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Rh(III), Pd(II), Pt(IV) und Au(III) Komplexe von 2-Thiopyrimidin Derivaten

Zusammenfassung Es wurden einige neue Thiopyrimidinderivate und deren Komplexe synthetisiert und mittels Elementaranalyse, IR und¹H-NMR charakterisiert: 4-Amino-5-nitroso-6-oxo-1,2,3,6-tetrahydro-2-thio-pyrimidin (TANH), dessen 2-Methylthio-Derivat (MTH), das Ammoniumsalz vonTANH (sTANH) und sechs neue Komplexe der Formeln Rh(MT)₂Cl · 2H₂O, Pd(MTH)₂Cl₂, Pt(MTH)₂Cl₄, Au(MTH)Cl₃, Pd(TANH)₂Cl₂ und Au(TAN ^–)Cl. Das thermische Verhalten der Verbindungen wurde ebenfalls untersucht.

     

Three Lead(II) Complexes in One Coordination Polymer, [Pb(TpyCl)Cl][Pb(TpyCl)Cl2][PbCl3](CH3OH)

[Pb(TpyCl)Cl][Pb(TpyCl)Cl₂][PbCl₃](CH₃OH) ( 1 ), a new coordination polymer of divalent lead with the ligand 4′‐chloro‐2,2′:6′,2"‐terpyridine (TpyCl), was obtained as single crystals by the branched tube method. The crystal structure contains three complexes, the cationic [Pb(TpyCl)Cl]⁺, the neutral [Pb(TpyCl)Cl₂] and the anionic [PbCl₃]^–, which are connected through bridging chlorides and hydrogen bonds to a two‐dimensional coordination polymer. In all three complexes, the arrangement around the Pb²⁺ ion suggests the existence of a stereoactive lone pair.     

Kinetics of radical decomposition of di(tert-butyl) trioxide

The kinetics of radical decomposition of di(tert-butyl) trioxide was studied by spectrophotometry from the consumption of an acceptor of free radicals, 2,6-di(tert-butyl)-4-methylphenol, in CFCl₃ and CH₂Cl₂ (in the latter case, in the presence of 0.1M Bu^tOOH). The activation parameters of the reaction (log(A/s ⁻¹)=14.8±1.2 and 14.1±1.6,E _a=21.6±1.4 and 20.1±1.9 kcal mol⁻¹ in CFCl₃ and CH₂Cl₂, respectively) and the probability of radical escape to the bulk (e=0.9±0.1) were determined. The known experimental and calculated values of the O−OO bond strength in trioxides were analyzed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 61–65, January, 1999.