Darstellung und eigenschaften von und reaktionen mit metallhaltigen heterocyclen: XXV. Synthese und eigenschaften neuer platina- und rhodacycloalkane durch substitution und oxidative addition einer CCl-bindung

The platinacyclopentane derivative [Cl(CH₂)₃R₂P](Cl)$\text{PtPR}{}_2\text{CH}{}_2\text{CH}{}_2\text{CH}{}_2$ is formed by action of Cl(CH₂)₃PR₂ on Pt(COD)₂ in n-hexane via the not isolable Pt[PR₂(CH₂)₃Cl]₂ (R  C₆H₁₁) by oxidative addition of a CCl bond to platinum. [μ-CIRh(CO)₂]₂ reacts in benzene with Cl(CH₂)₃PR₂ under partially CO substitution to give the stable intermediate Cl(OC)Rh[PR₂(CH₂)₃Cl]₂. In boiling toluene oxidative addition of a CCl bond to rhodium occurs under formation of the phospharhodacyclopentane [CI(CH₂)₃R₂P] Cl₂(OC)-$\text{RhPR}{}_2\text{CH}{}_2\text{CH}{}_2\text{CH}{}_2$ (R  C₆H₅). The ³¹P{¹H}-NMR spectra of the rhodium compound is characterized by an ABX system, that of the platinum by superposition of an ABX pattern with an AB spectrum.     

Die thermische reaktion von C5H5(CO)2FeNa mit benzimidchloriden C6H5(Cl)CNR

η⁵-C₅H₅(CO)₂FeNa reacts with the benzimide chlorides C₆H₅(Cl)CNR (R  CH(CH₃)₂, C₆H₅) in boiling THF to give the η¹-iminoacyl complexes η⁵-C₅H₅ (CO)₂Fe[η¹-C(C₆H₅)NR]. Alternatively, the new Fe complexes [η⁵-C₅H₅(CO)Fe$\text{C(C}{}_6\text{H}{}_5\text{)N(CH}{}_3\text{)C(C}{}_6\text{H}{}_5\text{)N}$CH₃PF₆ (IV) and [η⁵-C₅H₅(CO)₂FeC(C₆H₅)N(CH₃)C(C₆H₅)NCH₃]PF₆ (V) are formed under the same conditions, if R  CH₃. Hudrolysis of the CN single bond of the ligand in V, not stabilized by a chelate effects as in IV, results in the formation of [η⁵-C₅H₅(CO)₂FeC(C₆H₅)NHCH₃]PF₆ (VII). Reaction of η⁵-C₅H₅(CO)₂ with N-benyzylbenzimido chloride yields η⁵-C₅H₅(CO)₂FeCH₂C₆H₅ as the only isolated product.     

Darstellung und eigenschaften von und reaktionen mit metallhaltigen heterocyclen XXII. Synthese, eigenschaften und kristallstruktur des sechsgliedrigen heterocyclus [(h-C5H5)NiSP(CH3)2]2 und dessen verhalten gegenüber alkinen

The heterocycle [(h⁵-C₅H₅)NiSP(CH₃)₂]₂ is obtained by treatment of (h⁵-C₅H₅)₂Ni with (CH₃)₂HPS in toluene and crystallizes monoclinic in the space group P2₁/c with Z = 2. The highly reactive three-membered ring (h⁵-C₅H₅)$\text{NiSP}$(CH₃)₂ which is a dissociation product of [(h⁵-C₅H₅)NiSP(CH₃)₂]₂, can be trapped with bis(methoxycarbonyl)acetylene to give the PS containing nickelacyclopentadiene (h⁵-C₅H₅)$\text{NiSP(CH}{}_3\text{)}{}_2\text{CRC}$R (R  CO₂CH₃).     

Structure,spectral properties and interconversions of bis-niobocenes and their dianions. The crystal and molecular structure of [(η5-C5H4SiMe2OSiMe2-η5 : η1-C5H3)2Nb2H2] [Na(OEt2)2]2

Electron-acceptor properties of bis-niobocenes (η⁵-C₅H₄Y)(H)$\text{Nb(η}{}^5\text{: η}{}^1\text{-C}{}_5\text{H}{}_3\text{X)}{}_2\text{N}$b(H)(η⁵-C₅H₄Y) with X  Y  H and XY  SiMe₂OSiMe₂have been investigated. Bis-niobocenes are shown to readily add two electrons forming stable salts of the corresponding dianions [(η⁵-C₅H₄Y)(H)Nb(η⁵ : η¹- C₅H₃X)₂Nb(H)(η⁵-C₅H₄Y)]^2-. The surplus electrons can be removed to give quantitative regeneration of initial neutral bis-niobocenes. The crystal and molecular structure of the title compound has been determined; R  0.044, interatomic distance are Nb…Nb 3.93, NbH 1.62, average NbC(π) 2.36, NbC(σ) 2.31 Å, other distances correspond to the usually observed values. Unlike the neutral bis-niobocenes, there is no direct metalmetal bond in the dianionic structures. This conclusion is supported by electronic spectra of neutral and dianionic species.     

The preparation and characterization of a platinum ether complex

The reaction of [Pt((F₃C)CCH(CF₃))(P(C₂H₅)₃)₂CH₃OH]PF₆ with allene in methanol affords a novel metallocyclic ethereal complex [$\text{Pt((F}{}_3\text{C)CHC(CF}{}_3\text{)C(CH}{}_3\text{)CH}{}_2\text{O}$CH₃)(P(C₂H₅)₃)₂]PF₆, which has been characterized by ¹H, ²H, ¹⁹F and ³¹P NMR spectroscopy. Its structure has also been determined by a single crystal X-ray analysis. The crystal are monoclinic, space group P2₁/n, with cell dimensions a 20.012(5), b 17.222(5), c 8.902(3) Å and β 91.54(5)°. The structure was refined by full matrix least-squares methods on F, using 3097 unique observations collected by automated four circle diffractometer. Refinement converged at R  0.066. The Pt atom has a distorted square-planar coordination geometry, with cis P atoms, and PtP distances of 2.219(4) Å (trans to O) and 2.324(4) Å (trans to C). These results show the ethereal group is a weak ligand to platinum(II) but because of the chelating effect, its displacement by other ligands is thermodynamically not favorable. The mechanism of formation of the ethereal complex is also discussed.     

Cyclopentadienyl-ruthenium and -osmium chemistry: XXIV. Some complexes containing the olefinic tertiary phosphine 2-CH2CHC6H4PPh2 (sp): X-ray structures of one isomer of OsBr(sp)(η-C5H5), and of Ru(η3-S2CCHMeC6H4PPh2-2)(η-C5H5), containing an η3-dithiocarboxylato group

Reactions between MX(PPh₃)₂(η-C₅H₅) (M = Ru, X = Cl; M = Os, X = Br) and 2-CH₂CHC₆H₄PPh₂ afford $\text{MX(η}{}^2\text{-CH}{}_2\text{CHC}{}_6\text{H}{}_4\text{P}$Ph₂)(η-C₅H₅); the Os complex is obtained in two isomeric forms. The X-ray structure of the major isomer shows the CC double bond (OsC, 2.214, 2.195 Å; CC, 1.57 Å) is almost coplanar with the OsBr vector, with the terminal C cis to Br; the minor isomer is assumed to have the alternative, more sterically congested conformation, with the β-C cis to Br. The chlororuthenium complex reacts with NaOMe/MeOH to give the corresponding hydrido complex, which also exists as two isomers in solution; reaction of this complex with CS₂ gives the expected dithio acid derivative $\text{Ru(S}{}_2\text{CCHMeC}{}_6\text{H}{}_4\text{P}$Ph₂)(η-C₅H₅), together with small amounts of a complex assumed to be $\text{Ru[S}{}_2\text{C(CH}{}_2\text{)}{}_2\text{C}{}_6\text{H}{}_4\text{P}$Ph₂](η-C₅H₅). The X-ray structure of the major product reveals an unusual η³-S₂C mode of coordination of the dithio acid fragment (RuS, 2.418, 2.426(1) Å; RuC 2.175(4) Å). Crystals of OsBr(η²-CH₂CHC₆H₄P)Ph₂)( η-C₅H₅) are monoclinic, space group P2₁/n, with a 12.696(2), b 21.719(6), c 15.929(3) Å, β 79.77(2)°, Z = 8; 2867 data (I > 2.5σ(I)) were refined to R = 0.040, R_w = 0.044. Crystals of $\text{Ru(η}{}^3\text{-S}{}_2\text{CCHMeC}{}_6\text{H}{}_4\text{P}$Ph₂)(η-C₅H₅) are orthorhombic, space group Pbca, with a 8.921(2), b 15.982(9), c 32.216(5) Å, Z = 8; 1685 data (I > 2.5σ(I)) were refined to R = 0.027, R_w = 0.030.     

Formation of an iridium σ-cyclopropane complex by the intramolecular activation of a cyclopropylphosphine: Rearrangement to a chelating σ-vinyl complex

When (t-Bu)₂PCH₂CHCH₂CH₂ is combined with [IrCl(C₈H₁₄)₂]₂ in toluene, the σ-bound cyclopropane complexes

(P(t-Bu)₂CH₂$\text{CHCH}{}_2\text{C}$H₂) (1a, 1b) are formed. Complexes 1a,1b react readily with H₂ to form IrClH₂P(t-Bu)₂CH₂$\text{CHCH}{}_2\text{C}$H₂)₂ (2). In polar solvents 1a,1b isomerize to the σ-vinyl chelated complex $\text{IrClH(P(t-Bu)}{}_2\text{CH}{}_2\text{C(CH}{}_3\text{)C}$H)(P(t-Bu)₂CH₂$\text{CHCH}{}_2\text{C}$H₂) (3). The structure of this 5-coordinate, 16-electron Ir^III complex was deduced from spectroscopic data, reaction chemistry, and from the crystal structure of its CO adduct (4). Compound 4 crystallizes in the monoclinic space group C_2h⁵-P2₁/n (a 15.610(14), b 15.763(16), c 11.973(13) Å, and β 104.74(5)°) with 4 molecules per unit cell. The final agreement indices for 2326 reflections having F_o² > 3σ(F_o²) are R(F) = 0.089 and R_w(F) = 0.095 (271 variables) while R(F²) is 0.148 for the 3423 unique data. Bond lengths in the 5-atom chelate ring $\text{IrPCCC}$ are IrP 2.341(4), PC 1.857(26), CC 1.520(30), CC 1.341(25), and CIr 1.994(21) Å. The IrCl distance is 2.479(5) Å.     

Molecular structure of 1,1-dichloroethylene as studied by gas electron diffraction and microwave data. Estimation of equilibrium structure by an extended anharmonic model analysis

The r_z structure of 1,1-dichloroethylene has been determined by a joint analysis of the electron diffraction intensity and the rotational constants as follows: $\text{r}{}_{\mathrm{<mtext>z</mtext>}}\text{(}\text{CH}\text{) = 1.088 ± 0.011, r}{}_{\mathrm{<mtext>z</mtext>}}\text{(}\text{CC}\text{) = 1.329 ± 0.003, r}{}_{\mathrm{<mtext>z</mtext>}}\text{(}\text{CCl}\text{) = 1.725 ± 0.002}\text{A}\text{?}\text{, ∠}{}_{\mathrm{<mtext>z</mtext>}}\text{HCH}\text{= 121.4 ± 0.7}\text{and}\text{∠}{}_{\mathrm{<mtext>z</mtext>}}\text{ClCCl}\text{= 114.1 ± 0.2°}$. The uncertainties represent estimated limits of error. The observed structural parameters are compared with those for related compounds and the systematic trends in the bond lengths and bond angles are discussed. The effective constants representing anharmonicity have been obtained from an analysis of the isotopic differences in the r_z structure. By using the r_z parameters and the effective constants, the equilibrium structure has been estimated as follows: $\text{r}{}_{\mathrm{<mtext>e</mtext>}}\text{(}\text{CH}\text{) = 1.079 ± 0.012, r}{}_{\mathrm{<mtext>e</mtext>}}\text{(}\text{CC}\text{) = 1.324 ± 0.005, r}{}_{\mathrm{<mtext>e</mtext>}}\text{(}\text{CCl}\text{) = 1.721 ± 0.003}\text{A}\text{?}\text{, ∠}{}_{\mathrm{<mtext>e</mtext>}}\text{HCH}\text{= 120.5 ± 0.8}\text{and}\text{∠}{}_{\mathrm{<mtext>e</mtext>}}\text{ClCCl}\text{= 114.0 ± 0.3°}$.     

Cyclometallation reactions XII. On the effect of various leaving groups on internal metallation reactions with alkylmanganese complexes

The interaction of azobenzene and MnR(CO)₅ (R  Me, Et, CH₂Ph, CH₂-C₆Me₅, COCF₃, COCH₂C₆F₅, COCH₂OPh, Ph or C₆F₅) affords M$\text{n(C}{}_6\text{H}{}_4\text{NN}$Ph)-(CO)₄, together with a binuclear complex Mn₂(CO)₆(C₁₂H₁₀N₂) in some cases. The metallation reaction is shown to proceed most readily with Mn-(CH₂Ph)(CO)₅; with this reagent, the metallated complexes M$\text{n(C}{}_6\text{H}{}_4\text{CH}{}_2\text{P}$Me₂)-(CO)₃[PMe₂(CH₂Ph)] (two isomers) and M$\text{n(C}{}_6\text{H}{}_4\text{CH}{}_2\text{A}$sMe₂(CO)₄ have been obtained on treatment with EMe₂(CH₂Ph) (E  P and As, respectively).     

Structure of trans-chloro-1,4-bis(ϱ-methoxyphenyl)-1,4-diaza-3methylbutadiene-2-yl-bis(triphenylphosphine)-palladium(II)

The structure of the compound trans-[PdCl {$\text{C(N-?-C}{}_6\text{H}{}_4\text{OMe)C}$(Me)N-?-C₆H₄OMe} (PPh₃)₂] was solved, using a conventional combination of Patterson and Fourier functions, least-squares refinements and electron density difference maps, to a reliability index R of 0.069 for the 2923 observed reflections collected by four-circle diffractometer. The palladium arom is surrounded in a roughly planar fashion by two trans phosphorus atoms, a chlorine atom, and a σ-bonded carbon atom of the diazabutadienyl group. This group assumes a trans configuration, the NCCN fragment being virtually planar and nearly normal to the mean coordination plane. The Pdligand bond lengths are: PdC 1.98(1), PdCl 2.41(1),PDP(1) 2.33(1) and PdP(2) 2.35(1) Å.     

Reactions and properties of some trimethyleneplatinum(IV) complexes: X. Reaction with iodide and thiocyanate ions

The reaction between the platinacyclobutanes [$\text{PtX}{}_2\text{(CH}{}_2\text{CRR′C}$H₂)L₂] (X  Cl, Br; L  C₅H₅N, 4-CH₃C₅H₄N; R, R′  H, CH₃; R  H, R′  CH₃, C₆H₅) and iodide and thiocyanate ions in methyl cyanide solution has been studied. The C₃ moiety is eliminated as the cyclopropane and the process is first order with respect to the platinacyclobutanes and zero to half order with respect to the salt (MY). With the iodides the rate increases in the order Li < Na < K, Et₄N, and methyl substitution in the cyclobutane ring reduces the rate of reaction with Et₄NI. Added pyridine retards the reaction when L  C₅H₅N (X  Cl; R, R′  H) and added dimethylsulphoxide accelerates it.The mechanism suggested involves dissociation of an L ligand and attack of Y^? ions and of M⁺Y^? ion pairs on the five-coordinate intermediate formed.     

Isomerisation in the chemistry of platinacyclobutane complexes

The platinacyclobutane complexes PtCl₂L₂(C₃H₅Me)], L  pyridine, CD₃CN, or tetrahydrofuran, exist as mixtures of isomers containing P$\text{tCH}{}_2\text{CHMeC}$H₂ or P$\text{tCHMeCH}{}_2\text{CH}{}_2$ groups in rapid equilibrium. Decomposition occurs in some cases to give [PtCl₂L(CH₃CH₂CHCH₂)]. Stereospecific skeletal isomerisation also occurs in metallocyclobutanes containing the groups P$\text{tCHRCHRC}$H₂  P$\text{tCHRCH}{}_2\text{C}$HR, when R  aryl further decomposition gives ν-allylplatinum complexes.     

Thermodynamic characterization of the melting of a series of polyesteramides

The changes in enthalpy, entropy and volume upon melting have been determined by dilatometric and differential scanning calorimetry measurements for four polyesteramides of the type:

$\text{-[-}\text{COφCONH(CH}{}_2\text{)}{}_{\mathrm{n}}\text{}\text{NHCOφCOO(CH}{}_2\text{)}{}_{\mathrm{m}}\text{}\text{O}\text{-]-}{}_{\mathrm{x}}$

with the following values for n and m; 6-6, 12-2, 12-6 and 12-12. The changes in each state function vary quite regularly with the number of CH₂ groups/repeating unit. A comparison is made between experimental data on the entropy of fusion and theoretical predictions. There is emphasis on the influence on the thermodynamics of melting of the rigidity of the -OCO-φ-CONH- residues and, in particular, of the persistence in the molten state of many interchain hydrogen bonds.     

The importance of steric factors in the formation and structures of heterobinuclear wedge-like sandwich derivatives. The crystal and molecular structure of niobocenehydrido-(σ,π-cyclopentadienylidene)iron(dicarbonyl)(Nb—fe)

CpFe(CO)₂CH₃ reacts with Cp₂NbH made from Cp₂NbBH₄ and Et₃N to give Cp₂$\text{NbH(μ-C}{}_5\text{H}{}_4\text{)F}$e (III). As shown by X-ray diffraction, III contains the Cp₂NbH sandwich fragment with a 46.8° angle between the rings linked with the dicarbonyliron moiety by the NbFe bond (2.968 Å), observed for the first time, and a cyclopentadienyl bridge C₅H₄, involving the NbC. σ-bond (2.189 Å) and C₅H₄Fe π-bond (2.085 Å). A probable reaction scheme leading to III and general patterns of formation of other heterobinuclear derivatives of sandwich complexes Cp₂MLM′(L′)n are discussed. The importance of steric effects due to nonbonded interligand interactions between the M′(L′)n fragment and the sandwich system is emphasized. Increase of steric strain in the binuclear system facilitates its unusual transformations.     

Metallierungsreaktionen an cyclometallierten komplexen des typs Mo-C6H4CH2PR2)2(M = Pd,Pt)

The complexes of type $\text{M}\text{o}\text{-C}{}_6\text{H}{}_4\text{CH}{}_2\text{P}$R₂)₂ (M = Pd, Pt) are readily deprotonated by n-Buli under various conditions yielding μ-C-bis-dilithiated species. The resulting carbanions are attacked by the electrophiles Mel, Me₃SiCl and Ph₂PCl to form the corresponding disubstituted derivatives. The reaction with AuCl . PPh₃ yields heterobimetallic complexes with two different MC σ-bonds. The compounds obtained are analytically and spectroscopically characterized.     

Polymérisation cationique du chloro-1 butadiène et copolymérisation avec l'isobutène

The cationic homopolymerization of 1-chlorobutadiene and its copolymerization with isobutene have been carried out in dichloromethane solution. The catalyst-cocatalyst pairs used were AlEt₂Cl-(CH₃)₃CCl and AlEtCl₂-(CH₃)₃CCl. In the latter case, the use of (CH₃)₃CCl was not necessary. According to experimental conditions, high molecular weight copolymers ($\text{M}{}_{\mathrm{n}}\text{= 200,000}$) insoluble in CH₂Cl₂, or soluble low polymers ($\text{M}{}_{\mathrm{n}}\text{= 20,000}$) were obtained. Homopoly-1-chlorobutadienes were soluble low molecular weight polymers ($\text{M}{}_{\mathrm{n}}\text{= 10,000}$). The 1-chlorobutadiene units in the polymers are nearly exclusively 3,4 (mainly trans). Consequently, this method is not convenient to prepare elastomers with a 1,4 structure similar to that of chlorinated butyl rubber.     

Darstellung und eigenschaften von und reaktionen mit metallhaltigen heterocyclen: V. Synthese,reaktionen und struktur neuartiger manganacycloalkane

The colourless, six- and seven-membered manganacycloalkanes (OC)₄$\text{MnPR}{}_2\text{OCH}{}_2\text{XC}$H₂ are obtained by reaction of Na₂[(OC)₄MnPR₂O] with the bis(triflate)alkanes (YCH₂)₂X (R = C₆H₅; X = CH₂, C(CH₃)₂, CH₂CH₂; Y = CF₃SO₃). CO or SO₂ can be inserted into the reactive MnC-σ bonds under ring expansion. Some characteristic IR and ¹H NMR data are discussed. (OC)₄$\text{MnPR}{}_2\text{OCH}{}_2\text{CH}{}_2\text{C}$H₂ crystallizes monoclinic in the space group P2₁/c with Z = 4.     

Cationic and alkynyl complexes of the trans(mesityl)bis(phenyldimethylphosphine)nickel(II) moiety

A cationic complex, trans-[(mesityl)Ni(PPhMe₂)₂(NCMe)]ClO₄ (IIa), has been prepared rom trans-(mesityl)Ni(PPhMe₂)₂Br and silver perchlorate in acetone/acetonitrile. IIa reacts with several neutral ligands to give trans-[(mesityl)Ni(PPhMe₂)₂L]ClO₄ (L = 2-pic, 3-pic, 3,4-lut, 2,5-lut, methyl isonicotinate, N-ethyl imidazole, PPhMe₂, P(Ome)₃), with halide anions to give trans-(mesityl)Ni(PPhMe₂)₂X (X = Cl, NNN), and with terminal alkynes in the presence of triethylamine to give trans-(mesityl)Ni(PPhMe₂)₂CCR (R = H, Me, CH₂CH₂Oh, Ph, C₆H₄OMe-p). Some related alkynyl complexes trans-CCl₂CClNi(PPhMe₂)₂CCR (R = H, Me, Ph, C₆H₄OMe-p) and trans-{(o-MeO)₂C₆H₃}Ni(PPhMe₂)₂CCr (R = H, Ph) also have been prepared from the corresponding trans-R′Ni(PPhMe₂)₂Cl, silver perchlorate and HCCR in acetonitrile-triethylamine. trans-(Mesityl)Ni(PPhMe₂)₂CCH reacts with methanol in the presence of perchloric acid to give a cationic carbne complex, trans-[(mesityl)Ni(PPhMe₂)₂{C(OMe)Me}]ClO₄.     

Platinum(0) complexes of 3-arylthiete 1,1-dioxides

3-Phenyl- and 3-p-bromophenyl-thiete 1,1-dioxides react with [Pt(trans-stilbene)(PPh₃)₂] and [Pt(AsPh₃)₄] to give the complexes [Pt($\text{CHCrCH}{}_2\text{S}$O₂)(MPh₃)₂] (R  Ph, p-BrC₆H₄; M P, As).