Synthesis and molecular structure of [Rh3(μ-PPh2)3(CO)6(PPh2-H)], an unusual six-membered inorganic ring complex

Reaction of [{Rh(μ-Cl)(CO)₂}₂] with PPh₂H in CO-saturated ethanol yields [Rh₃(μ-PPh₂)₃ (CO)₆ (PPh₂H)], a red trinuclear cluster of rhodium containing a near-planar six-membered Rh₃P₃ ring; this compound reversibly undergoes elimination of CO and PPh₂H to afford [Rh₃(μ-PPh₂)₃(CO)₅].     

Variable-Temperature and -Pressure 31P-NMR Study of the Intramolecular PPh3 Migration in the Cluster Compound [Ir2Rh2(CO)11PPh3]

The reaction of [Ir₂Rh₂(CO)₁₂] with 1 mol-equiv. of PPh₃ yields [Ir₂Rh₂(CO)₁₁PPh₃] ( 1 ) as a mixture of two isomers with the phosphine ligand axially bound either to one basal Rh-atom in the kinetically preferred isomer 1 R or to one basal Ir-atom in the thermodynamically preferred isomer 11 . Both isomers are fluxional on the ¹³C-NMR time scale at low temperature due to CO scrambling. Around room temperature, a new type of fluxional process starts to operate which is responsible for the isomerisation 1R?11 , i.e. the intramolecular migration of the reputedly inert PPh₃ ligand from one metal centre to another. The activation volumes of conversions 1R → 11 and 11 → 1R are both positive, indicating that the migration of PPh₃ is dissociative in character. This article reports the first application of variable pressure ³¹P-NMR to mechanistic studies.     

Synthesis and structure of new homo-and heteroligand carbonyl cluster complexes with [Fe3(μ3-Q)(μ3-X)] core (Q = Se, Te; X = S, As)

New cluster complexes of iron [Fe₃Q(AsCp*)(CO)₉] (Q = Se, Te, Cp* = C₅(CH₃)₅) are synthesized with the square pyramidal cluster core Fe₃QAs. A suitable procedure of the synthesis of known heterochalcogenide [Fe₃QS(CO)₉] clusters is developed. Monosubstituted [Fe₃Q(AsCH₃)(CO)₈(PPh₃)] and disubstituted [Fe₃Q(AsCH₃)(CO)₇(PPh₃)₂] clusters formed in the reactions of [Fe₃Q(AsCH₃)(CO)₉] with PPh₃ are studied. In monosubstituted clusters, the phosphine ligand is coordinated in the axial position to the Fe atom in the base of the Fe₃QAs square pyramid, while in disubstituted clusters, both phosphine ligands coordinate the Fe atoms in the pyramid base, one ligand being in the axial and another one in the equatorial position. The NMR data support the possibility of migration of the Fe-Fe bonds in a triangle in the cluster core in the case of disubstituted clusters.     

Redox properties of (RC2R')Co2(CO)6-nLn and reactivity of (RC2R')Co2(CO)6-nLn towards PPh3[LPPh3, P(OEt)3]

Cyclic voltammetric studies of clusters (C₅H₅-C₂C₆ H₄-R-p)Co₂(CO)6-n L_n[n=0,2; L=PPh₃, P(OEt)₃] and (RCH₂C)₂Co₂(CO₄) (PPh₃)₂ on Pt electrode are described. The primary reduction (0 / ?1) and oxidation (+ 1 / 0) steps are considered as a mono-electron process for all clusters. For the clusters (C₅H₅C₂C₆H₄-R-p)Co₂(CO)₆, a good linear relation between reduction potential E_p^red and Hammett constant σ_p of R in the clusters is found. For the clusters (RC₂R')Co₂(CO)₄L₂, their radical anions are extremely unstable at room temperature and fragment into a series of mononuclear species, one of which is (RC₂R')Co(CO)₂PPh₃. The reaction of radical anions of (RC₂R')Co₂(CO)_6–n (PPh₃)_n(n=0,2) with PPh₃ also produces mononuclear species (RC₂R')Co(CO)₂PPh₃ which has been detected by means of cyclic voltammetry and ESR. The influence of R on redox properties of clusters is discussed.     

Synthese und Eigenschaften der heteronuklearen Metallatomcluster Re4(CO)12[μ3-GaRe(CO)5]4 und Re2(CO)3[μ-GaRe(CO)5]2

Synthesis and Properties of Heteronuclear Metal Atom Clusters Re₄(CO)₁₂[μ₃-GaRe(CO)₅]₄ and Re₂(CO)₈[μ-GaRe(CO)₅]₂ The title compounds were prepared by the reaction of gallium halides and dirhenium decacarbonyl. Crystals of the four-membered cluster Re₂(CO)₈[μ-GaRe(CO)₅]₂ gave at 300⁰C with aggregation of four Re atoms to an inner Re₄ tetrahedron the product Re₄(CO)₁₂(CO)[μ₃-GaRe(CO)₅]₄and with Ga₂I₃ shown by mass spectroscopic measurements the molecule ion Re₄(CO)₁₆+. In tetra-hydrofuran solution the cluster Re₄(CO)₁₂[μ₃-GaRe(CO)₅]₄ and the hydride Li[C₂H₅)₃BH] have formed the formyl complex Li₄{Re₄(CO)₁₂[μ₃ -GaRe(CO)₄(CHO)] ₄}, which was estimated by ¹H n. m. r. and i. r. spectroscopic data. Both synthesized gallium rhenium carbonyl clusters were characterized by i.r. spectroscopic measurements. The comparison of these results with those of the structurally known indium rhenium carbonyl clusters led to proposals of the molecule structure of the analogous gallium rhenium compounds.     

Ein- und zweikernige Dinitrosylkomplexe von Molybdän und Wolfram. Die Kristallstrukturen von (PPh3Me)2[WCl4(NO)2], (PPh3Me)2[MoCl3(NO)2]2 und von (PPh3Me)2[WCl3(NO)2]2

Mono- and Binuclear Dinitrosyl Complexes of Molybdenum and Tungsten. Crystal Structures of (PPh₃Me)₂[WCl₄(NO)₂], (PPh₃Me)₂[MoCl₃(NO)₂]₂, and (PPh₃Me)₂[WCl₃(NO)₂]₂ The complexes (PPh₃Me)₂[MCl₄(NO)₂] (M = Mo, W), and (PPh₃Me)₂[MCl₃(NO)₂]₂, respectively, are prepared by reactions of the polymeric compounds MCl₂(NO)₂ with triphenylmethylphosphonium chloride in CH₂Cl₂, forming green crystals. According to the IR spectra the nitrosyl groups are in cis-position in all cases. The tungsten compounds as well as (PPh₃Me)₂[MoCl₃(NO)₂]₂ were characterized by structure determinations with X-ray methods. (PPh₃Me)₂[WCl₄(NO)₂]: space group C2/c, Z = 4. a = 1874, b = 1046, c = 2263 pm, β = 119.99°. Structure determination with 3492 independent reflexions, R = 0.057. The compound consists of PPh₃Me^⊕ ions, and anions [WCl₄(NO)₂]^2? with the nitrosyl groups in cis-position (symmetry C_2v). (PPh₃Me)₂[WCl₃(NO)₂]₂: Space group C2/c, Z = 4. Structure determination with 2947 independent reflexions, R = 0.059. (PPH₃Me)₂[MoCl₃(NO)₂]₂: Space group P1 , Z = 1. a = 989, b = 1134, c = 1186 pm; α = 63.25°, β = 80.69°, γ = 69.94°. Structure determination with 3326 independent reflexions, R = 0.046. The compounds consist of PPh₃Me^⊕ ions, and centrosymmetric anions [MCl₃(NO)₂]₂^2?, in which the metal atoms are associated via MCl₂M bridges of slightly different lengths. One of the NO groups is in an axial position, the other one in equatorial position (symmetry C_2h).     

Formation of Unusual Complexes from the Reaction of [C(NMe2)3][(CO)4Fe{C(O)NMe2}] with InMe3; Crystal Structures of [C(NMe2)3]3[Fe2(CO)6(μ‐CO){μ‐InFe(CO)4(μ‐O2CNMe2)InFe(CO)4}] and [C(NMe2)3]2[{(CO)4Fe}2In(O2CNMe2)]·THF

The carbamoyl complex [C(NMe₂)₃][(CO)₄Fe{C(O)NMe₂}] ( 1 ) reacts with InMe₃ under loss of the methyl groups to produce a variety of compounds from which only the anionic cluster complexes [C(NMe₂)₃]₃[Fe₂(CO)₆(μ‐CO){μ‐InFe(CO)₄(μ‐O₂CNMe₂)InFe(CO)₄}] ([C N ₃]₃[ 2 ]) and [C(NMe₂)₃]₂[{(CO)₄Fe}₂In(O₂CNMe₂)]·THF ([C N ₃]₂[ 3 ]·THF) could be crystallized and characterized by X‐ray analyses. The anion [ 2 ]^3? has a Fe₂(CO)₉‐like structure and both anions contain the carbaminato ligand either in a bridging or in a chelating function.     

High Nuclearity Bimetallic Rhodium–Palladium Carbonyl Cluster Complexes. Synthesis and Characterization of Rh6(CO)16[Pd(PBu t 3)]3 and Rh6(CO)16[Pd(PBu t 3)]4

The reaction of Rh₄(CO)₁₂ with Pd(PBu ^t ₃)₂ yielded the high nuclearity bimetallic hexarhodium-tripalladium cluster complex Rh₆(CO)₁₆[Pd(PBu ^t ₃)]₃, 10, in 11% yield. Compound 10 was converted to the hexarhodium-tetrapalladium cluster Rh₆(CO)₁₆[Pd(PBu ^t ₃)]₄, 11, in 62% yield by reaction with an additional quantity of Pd(PBu ^t ₃)₂. Both compounds were characterized crystallographically. Structurally, both compounds consist of an octahedral cluster of six rhodium atoms with sixteen carbonyl ligands analogous to that of the known compound Rh₆(CO)₁₆. Compound 10 also contains three Pd(PBu ^t ₃) groups that bridge three Rh–Rh bonds along edges of the Rh₆ octahedron to give an overall D₃ symmetry to the Rh₆Pd₃ cluster. Compound 11 contains four edge bridging Pd(PBu ^t ₃) groups distributed across the Rh₆ octahedron to give an overall D_2d symmetry to the Rh₆Pd₄ cluster. Each Rh–Pd connection in both compounds contains a bridging carbonyl ligand that helps to stabilize the bond between the Pd(PBu ^t ₃) groups and the Rh atoms. Both compounds can be regarded as Pd(PBu ^t ₃) adducts of Rh₆(CO)₁₆.     

Regioselective homogeneous hydrogenation of heteroaromatic nitrogen compounds by use of [RuH(CO)(NCMe)2(PPh3)2]BF4 as the precatalyst

Summary The complex [RuH(CO)(NCMe)₂(PPh₃)₂]BF₄ (1) is an efficient and regioselective catalyst precursor for the hydrogenation of polyaromatic nitrogen compounds such as quinoline (Q), isoquinoline (iQ), indole (ln), 5,6- and 7,8-benzoquinoline (BQ) and acridine (A) under relatively mild reaction conditions (125 °C, 4 atm H₂). The order of individual initial rates was: A > Q > 5,6-BQ > 7,8-BQ > ln > iQ, reflecting both steric and electronic effects. For the regioselective homogeneous hydrogenation of A to 9,10-dihydroacridine (DHA) catalysed by complex (1), a kinetic study was carried out; the experimentally determined rate law was r = k ₁ [Ru] [H₂]. These findings are consistent with a mechanism involving the hydrogenation of [RuH(CO)(A)(NCMe)(PPh₃)₂]BF₄ to yield DHA and the unsaturated species [RuH(CO)(NCMe)(PPh₃)₂]BF₄ in the rate-determining step.     

Synthese und Kristallstrukturen von (PPh4)2[TeS3] · 2 CH3CN und (PPh4)2[Te(S5)2]

Synthesis and Crystal Structures of (PPh₄)₂[TeS₃] · 2 CH₃CN and (PPh₄)₂[Te(S₅)₂] (PPh₄)₂[TeS₃] · 2 CH₃CN was obtained by the reaction of PPh₄Cl, Na₂S₄ and Te in acetonitrile. With sulfur it reacts yielding (PPh₄)₂[Te(S₅)₂]. The crystal structures of both products were determined by X-ray diffraction. (PPh₄)₂[TeS₃] · 2 CH₃CN: triclinic, space group P1 , Z = 2, R = 0.041 for 4 629 reflexions; it contains trigonal-pyramidal [TeS₃]^2? ions with an average Te? S bond length of 233 pm. (PPh₃)₂[Te(S₅)₂]: monoclinic, P2₁/n, Z = 2, R = 0.037 for 2 341 reflexions. In the [Te(S₅)₂]^2? ion the tellurium atom has a nearly square coordination by four S atoms. Along with the Te atoms each of the two S₅ groups forms a ring with chair conformation.     

The Ylide Adduct SOC2(PPh3)2 as Complex Ligand. Reaction with [Mn2(CO)10] and InCl3; Crystal Structures of [(CO)4Mn(SOC2{PPh3}2)2][Mn(CO)5] and (H2C{PPh3}2)[InCl4]2

The betain‐like SOC₂(PPh₃)₂ ( 1a ) reacts with [Mn₂(CO)₁₀] in THF to produce the salt‐like complex [(CO)₄Mn(SOC₂{PPh₃}₂)₂][Mn(CO)₅] ( 2 ). 1a is bonded via the sulfur atoms which are arranged in trans position in the octahedral environment of the manganese atom. With InCl₃ from CH₂Cl₂ solution the addition product [Cl₃In(SOC₂{PPh₃}₂)] ( 3 ) is obtained along with the salt (H₂C{PPh₃}₂)[InCl₄]₂ ( 4 ), which is the result of proton abstraction from the solvent. The crystal structures of 2· 0.5THF and 4· CH₂Cl₂ are reported. The compounds are further characterized by IR and ³¹P NMR spectroscopy.     

The reaction of Ru3(CO)12 with HC9PPh2)3. Characterisation of Ru3(CO)9[HC(PPh2)3], and crystal and molecular structure of Ru3(CO)9[HC(PPh2)(PhPC6H4PPh)]·CHCl3

Reaction of Ru₃(CO)₁₂ with HC(PPh₂)₃ leads to a variety of products, two of which have been characterised. One is the symmetrically capped product Ru₃(CO)₉[HC(PPh₂)₃], which was characterised spectroscopically. The second product was characterised crystallographically as Ru₃(CO)₉[HC(PPh₂)-(PhPC₆H₄PPh)]-CHCl₃.     

Kinetics and mechanisms of homogeneous catalytic reactions. Part 5. Regioselective reduction of heteroaromatic nitrogen compounds catalysed by [OsH(CO)(NCMe)2(PPh3)2]BF4

The [OsH(CO)(NCMe)₂(PPh₃)₂]BF₄ complex (1) is an efficient and regioselective precatalyst for the hydrogenation of the nitrogen-containing ring of quinoline (Q), isoquinoline (iQ), 5,6- and 7,8-benzoquinoline (BQ), and acridine (A) under mild reaction conditions (125 °C and 4 atm H₂). Kinetic studies of the hydrogenation of Q and iQ to give tetrahydroquinoline (THQ) and tetrahydroisoquinoline (THiQ), respectively, lead to the rate law r = K ₁ k ₂/(1 + K ₁[H₂])[Os][H₂]², which becomes r = K ₁ k ₂[Os][H₂]², at low hydrogen concentrations (below 1 atm H₂); the catalytically active species is of the type [OsH(CO)(L)( ¹-N)(PPh₃)₂]BF₄ [(2a): L = NCMe, N = Q; (2b): L = N = iQ]. The generic mechanisms involve a rapid and partial hydrogenation of the coordinated substrate (N) of complex (2) to yield the corresponding dihydroderivative (DHN) species [OsH(CO)(L)( ¹-DHN)(PPh₃)₂]BF₄ [(3a): L = NCMe, DHN = DHQ; (3b): L = iQ or THiQ, DHN = DHiQ], followed by the rate-determining second hydrogenation of the DHN ligand, which yield [OsH(CO)(L)( ¹-THN)(PPh₃)₂]BF₄ [(4a): L = NCMe, THN = THQ; (4b): L = iQ or THiQ, THN = THiQ]; substitution of the THN ligand by a new molecule of the respective substrate regenerates the active species and restarts the catalytic cycle. For the hydrogenation of acridine to give 9,10-dihidroacridine (acridane), the rate law was r = k ₁[Os][H₂]; the mechanism involves the hydrogenation of the active species [OsH(CO)(NCMe)( ¹-A)(PPh₃)₂]BF₄ (2c) to yield acridane and the unsaturated species [OsH(CO)(NCMe)(PPh₃)₂]BF₄ as the rate-determining step.     

Umsetzung von C(NMe2)4 mit Ni(CO)4 – Synthesen und Strukturen von [C(NMe2)3][(CO)3NiC(O)NMe2], [C(NMe2)3]2[Ni5(CO)12] und [C(NMe2)3]3[Ni6(CO)12][O2CNMe2]

Reaction of C(NMe₂)₄ with Ni(CO)₄ – Syntheses and Structures of [C(NMe₂)₃][(CO)₃NiC(O)NMe₂], [C(NMe₂)₃]₂[Ni₅(CO)₁₂], and [C(NMe₂)₃]₃[Ni₆(CO)₁₂][O₂CNMe₂] The reaction of C(NMe₂)₄ with Ni(CO)₄ in THF produces the carbamoyl complex [C(NMe₂)₃][(CO)₃NiC(O)NMe₂] ( 1 ); side products are the purple cluster compound [C(NMe₂)₃]₂[Ni₅(CO)₁₂] · THF ( 2 · THF) and the red cocristallization product [C(NMe₂)₃]₃[Ni₆(CO)₁₂][O₂CNMe₂] ( 3 ). All compounds were studied by X‐ray diffraction analyses. The cations of 3 are all disordered but not those of 1 and 2 . The unit cell of 1 contains two crystallographically independent anions (I and II) which differ in the dihedral angle between the plane of the carbamoyl ligand and the plane defined by the atoms C_Carbamoyl–Ni–CO amounting 0° in the anion I and 18° in the anion II.     

PPh4[As3S3Cl4] und PPh4[As3S3Br4]

PPh₄[As₃S₃Cl₄] and PPh₄[As₃S₃Br₄] When As₂S₃ reacts with PPh₄X and HX in 1,2-C₂H₄X₂ (X = Cl, Br), the title compounds are obtained as minor products; the main products are PPh₄[As₂SX₅]. Their crystal structures were determined by X-ray diffraction. PPh₄[As₃S₃Cl₄]: a = 1187.7, b = 1090.9, c = 1191.8 pm, α = 82.91, β = 88,93, γ = 88.52°; twins with twin plane (100); R = 0.109 for 1618 observed reflexions of one twin crystal. PPh₄[As₃S₃Br₄]: a = 1119.7, b = 1177.5, c = 1204.1 pm, α = 81.59, β = 85.88, γ = 88.25°; R = 0.061 for 2331 observed reflexions. Both compounds crystallize in the space group P1 , Z = 2, and can be considered to be isotypic. Nevertheless, PPh₄[As₃S₃Br₄] does not form twins as PPh₄[As₃S₃Cl₄]. The crystals consist of PPh₄⁺ and [As₃S₃X₄]^? ions. In the anions, the three As atoms of an As₃S₃ ring in the chair conformation are commonly joined to an X atom and each As atom is bonded to one further terminal X atom. Cations and anions are packed in alternating layers.     

Die Kristallpackung in drei Modifikationen von PPh4[ReO(S4)2] und PPh4[ReS(S4)2]

The Crystal Packing in three Modifications of PPh₄[ReO(S₄)₂] and PPh₄[ReS(S₄)₂] Mixed crystals PPh₄[ReS(S₄)₂]_0,63[ReO(S₄)₂]_0,37 were obtained from PPh₄Cl, ReCl₅ and Na₂S₄ in acetonitrile. Their crystal structure corresponds to the known structure of this kind of compound (space group P2₁/n). In a similar reaction with ReBr₅ instead of ReCl₅, PPh₄[ReO(S₄)₂] was obtained in small yield. Its triclinic crystal structure was determined by X‐ray crystallography (space group P1). It contains cation pairs (PPh₄⁺)₂ such as they have been found in many other instances. In contrast, the crystal structures of the mixed crystals and of one known modification of PPh₄[ReS(S₄)₂] have PPh₄⁺ columns similar to compounds crystallizing in the space group P4/n, albeit in a severely distorted manner; their space group P2₁/n is a subgroup of P4/n with a doubled unit cell. In another modification of PPh₄[ReS(S₄)₂] (space group P2₁/c) the columns are less distorted, but arranged in a different way.     

Reactivity of fac-[PPN][Fe(CO)3(TePh)3]: Structure of Fe2(μTePh)2(NO)4

Addition of NOBF₄ to fac-[PPN][Fe(CO)₃(TePh)₃] in THF at ambient temperature results in formation of Fe₂(μ-TePh)₂(NO)_4l Fe₂(?TePh)₂(CO)₆ and organic products. Methylation of fac-[PPN][Fe(CO)₃- (TePh)₃] by Mel or [Me₃O][BF₄] leads to the known dimer Fe₂(μ.-TePh)₂(CO)₆ and organic products. Fe₂(μ-TePh)₂(NO)₄ crystallizes in the orthorhombic space group P bca, with a = 12.701(5) Å, b = 6.7935(16) Å, c = 21.299(9) Å, V = 1837.8(11) ų, and Z = 4. The core geometry of Fe₂(μ-TePh)₂(NO)₄ is best described as a Fe₂Te₂ planar rhombus with Te-Fe-Te bond angle 112.09(4)°. A Fe-Fe bond (length 2.827(2) Å) is proposed for Fe₂(μ-TePh)₂(NO)₄ on the basis of the 18-electron rule. The iron atom adopts a distorted tetrahedral geometry with acute bridge Fe-Te-Fe angles 67.91(3)°, and bridging Fe-Te bond of length 2.53(1) Å.     

Reaktionen von Zinnchloriden mit Polysulfiden. Die Kristallstrukturen von (PPh4)2[SnCl2(S6)2], (PPh4)2[Sn4Cl4S5(S3)O] und (PPh4)2[SnCl6] · S8 · 2CH3CN

Reaction of Tin Chlorides with Polysulfides. Crystal Structures of (PPh₄)₂[SnCl₂(S₆)₂], (PPh₄)₂[Sn₄Cl₄S₅(S₃)O], and (PPh₄)₂[SnCl₆] · S₈ · 2CH₃CN . The reaction of PPh₄[SnCl₃] with Na₂S₄ in acetonitrile in the presence of small amounts of water yields (PPh₄)₂[Sn₄Cl₄S₅(S₃)O] and minor amounts of (PPh₄)₂[SnCl₂(S₆)₂], PPh₄Cl · 2S₈ and (PPh₄)₂[SnCl₆]. SnCl₄ is partially reduced by (PPh₄)₂S_x, PPh₄[SnCl₃] and (PPh₄)₂[SnCl₆] · S₈ · 2CH₃CN being produced. According to the X-ray crystal structure determination the [Sn₄Cl₄S₅(S₃)O]^2?-ion consists of an O atom that is coordinated by four Sn atoms which in turn are liked with one another by five single S atoms and one S₃ group. In the [SnCl₂(S₆)₂]^2?-ion the Sn atom is octahedrally coordinated by two Cl atoms in trans arrangement and by two chelating S₆ groups. Octahedral [SnCl₆]^2? ions and S₈ molecules in the crown conformation are present in (PPh₄)₄[SnCl₆] · S₈ · 2CH₃CN.     

Synthesen und Strukturen neuer amido- und imidoverbrückter Cobaltcluster: [Li(THF)2]3[Co3(μ2-NHMes)3Cl6] (1), [Li(DME)3]2[Co18(μ4-NPh)3(μ3-NPh)12Cl3] (2), [Li(DME)3]2[Co6(μ4-NPh)(μ2-NPh)6(PPh2Et)2] (3) und [Li(THF)4][Co8(μ3-NPh)6(μ2-NPh)3(PPh3)2] (4)

Syntheses and Crystal Structures of new Amido- und Imidobridged Cobalt Clusters: [Li(THF)₂]₃[Co₃(μ₂-NHMes)₃Cl₆] (1), [Li(DME)₃]₂[Co₁₈(μ₄-NPh)₃(μ₃-NPh)₁₂Cl₃] (2), [Li(DME)₃]₂[Co₆(μ₄-NPh)(μ₂-NPh)₆(PPh₂Et)₂] (3), and [Li(THF)₄][Co₈(μ₃-NPh)₆(μ₂-NPh)₃(PPh₃)₂] (4) The reactions of cobalt(II)-chloride with the lithium-amides LiNHMes and Li₂NPh leads to an amido-bridged multinuclear complex [Li(THF)₂]₃[Co₃(μ₂-NHMes)₃Cl₆] ( 1 ) as well as to the imido-bridged cobalt cluster [Li(DME)₃]₂[Co₁₈(μ₄-NPh)₃(μ₃-NPh)₁₂Cl₃] ( 2 ). In the presence of tertiary phosphines two imido-bridged cobalt clusters [Li(DME)₃]₂[Co₆(μ₄-NPh)(μ₂-NPh)₆(PPh₂Et)₂] ( 3 ) and [Li(THF)₄][Co₈(μ₃-NPh)₆(μ₂-NPh)₃(PPh₃)₂] ( 4 ) result. The structures of 1 – 4 were characterized by X-ray single crystal structure analysis.     

Die Reaktion von Trichlornitromethan mit Eisencarbonylen Kristallstruktur von (PPh4)2[Fe2OCl6] · 2 CH2Cl2

Reaction of Trichloronitro Methane with Iron Carbonyls. Crystal Structure of (PPh₄)₂[Fe₂OCl₆] · 2 CH₂Cl₂ Trichloronitro methane reacts with Fe₂(CO)₉ or Fe₃(CO)₁₂ forming NO[FeOCl₂] which is composed of Nitrosyl ions and polymeric [FeOCl₂]^?. The reaction of NO[FeOCl₂] with POCl₃ affords Fe(O₂PCl₂)₃; with tetraphenyl phosphoniumchloride it forms the complex (PPh₄)₂[Fe₂OCl₆] which is soluble in CH₂Cl₂. The oxochloro ferrates are characterized by the aid of ⁵⁷Fe-Mössbauer spectra and by i.r. spectra. A single crystal of (PPh₄)₂[Fe₂OCl₆] · 2 CH₂Cl₂ was used to carry out a structural investigation by means of X-ray diffraction data (space group P1 , Z = 1, a = 1157.2(2), b = 1363.8(3), c = 1140.3(2) pm, α = 109.22(1)°, β = 95.23(1)°, γ = 67.24(2)°, R = 0.052 for 3814 reflexions with F₀ > 3σ). The [Cl₃Fe? O? FeCl₃]^2?-anion is found to have a centre of symmetry and thus, in accordance with the i.r. spectra, contains a linear bridge. High thermal parameters of the bridging oxygen atom and the chlorine ligands, however, allow interpretations as orientation disorder of slightly bent anions.