Crystal structure of a methyl(methoxy)carbene complex of nickel(II), trans-[Ni(C6Cl5)(PMe2Ph)2{C(OMe)Me}]BF4

The structure of a nickel(II) complex, trans-[Ni(C₆Cl₅)(PMe₂Ph)₂{C(OMe)Me}]BF₄, containing the simplest alkyl(alkoxy)carbene ligand has been determined by X-ray crystallography (R = 0.091). The geometry around the nickel atom is square-planar. The comparatively short NiC(1) bond length of 1.843(10) Å showed the presence of π-bonding in the nickel-carbene bond.     

Basische metalle : IX. Synthese und kristallstruktur von C5H5Co(PMe3)CS2. Reaktionen zu zweikernkomplexen mit Co(SCS)Cr- und Co(SCS)Mn-Brückenbindungen

C₅H₅Co(PMe₃)CS₂ (IV) is formed in practically quantitative yield in the reaction of C₅H₅Co(PMe₃)₂ (I) or the heterobinuclear complex C₅H₅(PMe₃)Co(CO)₂Mn(CO)C₅H₄Me (III) with CS₂. The crystal structure shows that the carbon disulfide bonds as a dihapto ligand through the carbon and one sulfur atom (S(2)) (CoC = 1.89, CoS(2) = 2.24 Å, S(2)CS(1) = 141.2°). The two CS bond lengths in IV (CS(2) = 1.68, CS(1) =1.60 Å) are greater than in free CS₂ (1.554Å) which is in agreement with the strong π-acceptor character of h²-CS₂ as shown in the spectroscopic data. IV reacts with Cr(CO)₅THF and C₅H₅Mn(CO)₂THF to give the complexes C₅H₅(PMe₃)Co(SCS)Cr(CO)₅ (V) and C₅H₅(PMe₃)Co(SCS)Mn(CO)₂C₅H₅ (VI) respectively, in which the sulfur atom S(1) that is not bound to cobalt coordinates to the 16-electron fragments Cr(CO)₅ and Mn(CO)₂C₅H₅. The spectroscopic data of IV, V and VI are discussed.     

Zur reaktion von metall-koordiniertem kohlenmonoxid mit yliden: XI. Einige neuartige η1-vinyl-komplexe des eisens durch deprotonierung kationischer carbenkomplexe mit trimethyl(methylen)phosphoran

Novel η¹-vinyl complexes of the type Cp(CO)(L)FeC(OMe)C(R)R′ (R = R′ = H, Me; R = H, R′ = Me; L = Me₃P, Ph₃P) are obtainied via methylation of the acyl complexes Cp(CO)(L)FeC(O)R (R = Me, Et, i-Pr) with MeOSO₂F and subsequent deprotonation of the resulting carbene complexes [Cp(CO)(L)FeC(OMe)R]SO₃F with the phosphorus ylide Me₃PCH₂. The same procedure can be applied for the synthesis of the pentamethylcyclopentadienyl derivative C₅Me₅(CO)(Me₃P)FeC(OMe)CH₂, while treatment of the hydroxy or siloxy carbene complexes [Cp(CO)(L)FeC(OR)Me]X (R = H, Me₃Si; X = SO₃CF₃) with Me₃CH₂ results in the transfer of the oxygen bound electrophile to the ylidic carbon. Some remarkable spectroscopic properties of the new complexes are reported.     

Substituted cyclopentadienyl complexes: II. 13C NMR spectra of some [(η5-C5H4Me)Fe(CO)(L)I] complexes

The ¹³C {¹H} NMR spectra of a series of complexes [(η⁵-C₅H₄Me)Fe(CO)(L)I] (L  t-BuNC, P(OMe)₃, PMe₃, PMe₂Ph, PMePh₃, PPh₃ and P(C₆H₁₁)₃) have been recorded and the five cyclopentadienyl resonances assigned to ring carbon atoms by means of CH correlated spectra. It has been observed that the C atoms ortho to the ring methyl group (C(2) and C(5)) as well as the quaternary C atom are always coupled to the ligand P atom. A correlation between the chemical shift difference Δ(C(2) – C(5)) and the Tolman cone angle, θ, has also been established.     

Basische metalle: LII. Synthese von carbenoid- und ylidcobalt(III)-komplexen aus substitutionslabilen cobalt(I)-vorstufen

The cyclopentadienylcobalt(I) compounds C₅H₅Co(PMe₃)P(OR)₃ (R = Me, Et, Prⁱ) and C₅H₅Co(C₂H₄)L (L = PMe₃, P(OMe)₃, CO) are prepared by ligand substitution starting from C₅H₅Co(PMe₃)₂ and C₅H₅Co(C₂H₄)₂. Whereas the reaction of C₅H₅Co(PMe₃)P(OMe)₃ with CH₂Br₂ mainly gives [C₅H₅CoBr(PMe₃)P(OMe)₃]Br, the dihalogenocobalt(III) complexes C₅H₅CoX₂(PMe₃) (X = Br, I) are obtained from C₅H₅Co(CO)PMe₃ and CH₂X₂. Treatment of C₅H₅Co(CO)PMe₃ or C₅H₅Co(C₂H₄)PMe₃ with CH₂ClI at low temperatures produces a mixture of C₅H₅CoCH₂Cl(PMe₃)I and C₅H₅CoCl(PMe₃)I, which can be separated due to their different solubilities. The same reaction in the presence of ligand L gives the carbenoidcobalt(III) compounds [C₅H₅CoCH₂Cl(PMe₃)L]PF₆ in nearly quantitative yields. If NEt₃ is used as the Lewis base, the ylide complexes [C₅H₅Co(CH₂PMe₃)(PMe₃)X]PF₆ (X = Br, I) are obtained. The PF₆ salts of the dications [C₅H₅Co(CH₂PMe₃)(PMe₃)L]²⁺ (L = PMe₃, P(OMe)₃, CNMe) and [C₅H₅Co(CH₂PMe₃)(P(OMe)₃)₂]²⁺ are prepared either from [C₅H₅Co(CH₂PMe₃)(PMe₃)X]⁺ and L, or more directly from C₅H₅Co(CO)PMe₃, CH₂X₂ and PMe₃ or P(OMe)₃, respectively. The synthesis of C₅H₅CoCH₂OMe(PMe₃)I is also described.     

Reaktionen von carben-komplexen mit tetramethylcyanoguanidin

Tetramethylcyanoguanidine, NCNC(NMe₂)₂, reacts with pentacarbonyl-[methoxy(phenyl)carbene]chromium, (CO)₅Cr[C(Ph)OMe], via substitution of the carbene ligand to give pentacarbonyl(tetramethylcyanoguanidine)chromium. X-ray structure analysis shows that the CrNCN fragment is nearly linear in the crystal, and that the CNC angle is 122.9(1)°. In solution rapid syn-anti isomerization at the NC double bond occurs. The reaction of tetramethylcyanoguanidine with pentacarbonyl[acetoxy(phenyl)carbene]-chromium and -tungsten, (CO)₅M-[C(Ph)OCO(O)Me] (M = Cr, W), yields (CO)₅M[C(PHNC(NMe₂)₂], where the acetoxy group of the carbene ligand is exchanged for the NC(NMe₂)₂ group of the cyanoguanidine.     

The crystal and molecular structure of η5-cyclopentadienyliodomethyl(methylthio)carbene-(triphenylphosphine)iridium(III) iodide

The crystal and molecular structure of η⁵-cyclopentadienyliodomethyl(methylthio)carbene(triphenylphosphine)iridium(III) iodide [IrI{C(Me)SMe}(η⁵-C₅H₅)(PPh₃)]I has been determined from three dimensional X-ray data in order to clarify the contribution of the α-sulphur atom to the bonding in this carbenoid complex.The compound crystallizes in space group Pbc2₁ with four formula units in a cell of dimensions a 9.745(6), b 15.201(8), and c 17.364(10) Å. Least-squares refinement of the structure has led to the final discrepancy index R = 0.047 for the 1655 symmetry-independent observable reflections. The coordination geometry about the iridium atom is approximately tetrahedral; the coordination positions are occupied by the η⁵-C₅H₅ ring center, the phosphorus, the iodide I(1) and the carbon C(6) of the C(Me)SMe ligand (IrRc 1.89, IrP 2.280(7), Ir(1) 2.651(2) and IrC(6) 2.03(3) Å).The bonding of the C(Me)SMe group indicates that this complex must be formulated as a C(Me)SMe complex of iridium(III).     

Metallkomplexe mit verbrückenden dimethylphosphidoliganden: VI. Zweikernkomplexe mit substituierten vinyldimethylphosphan-brückenliganden durch templatsynthese aus [(C5H5Co)2(μ-PMe2)2(μ-H)]+ und alkinen. Die kristallstruktur von [(C5H5Co)2(μ-PMe2)(μ-η4-Me2PC(CO2Me)CHC(OMe)O)]BF4

The hydrido-bridged dinuclear complex [(C₅H₅CO)₂(μ-PMe₂)₂(μ-H)]BF₄ (I) reacts with C₂(CO₂Me)₂ to produce a mixture of (C₅H₅Co)₂[μ-η⁴-Me₂PC(CO₂Me)C(CO₂Me)PMe₂] (II) and [(C₅H₅Co)₂(μ-PMe₂)(μ-η⁴-Me₂PC(CO₂Me)-CHC(OMe)O)]BF₄ (III). The X-ray structural analysis of III reveals that besides a dimethylphosphido bridge the cation contains a substituted vinyldimethylphosphine ligand which behaves as a 6-electron donor group and is coordinated via phosphorus and oxygen to the first cobalt and via the CC bond the second cobalt atom. The reactions of I with HC₂CO₂Me and CH₃C₂CO₂Me also give mixtures of products which contain the neutral component, (C₅H₅Co)₂[μ-η⁴-Me₂PCRC(CO₂Me)PMe₂] (IV: R  H; VII: R  CH₃), i.e., the structural analogue of II. The ionic products V, VI (obtained from HC₂CO₂Me) and VIII, IX (obtained from CH₃C₂CO₂Me) have been characterized by IR and NMR spectroscopy. {(C₅H₅Co)₂[μ-η⁴-PMe₂C(CH₃)C(CO₂Me)PMe₂](μ-H)}BF₄ (VIII) has independently been prepared by treatment of VII with HBF₄.     

Strukturuntersuchungen an mono- und bis-alkoxy(triphenylsilyl)-carben-komplexen des rheniums

Steric and electronic influences on bond lengths and angles at the carbene carbon atoms of cis-Re₂(CO)₉C(OR)SiPh₃ (I: R = CH₃, II, R = C₂H₅) and cis,trans-Re₂(CO)₈[C(OEt)SiPh₃]₂ (III) are discussed based on their structural analyses. I (ReRe 305.2(1) pm; ReC(carbene) 209(2) pm) and II (two independent molecules; ReRe 305.0(3) and 305.2(4) pm; ReC (carbene) 208(5) and 210(5) pm) differ by the cis and trans positions of the alkyl groups at the partial C(carbene)O double bonds. The change in configuration affects the bond angles at the carbene carbon. In III the carbene ligands are bonded to different rhenium atoms; cis to one Re atom and trans to the other Re atom (ReRe bond 309.1(2) pm). The ReC(carbene length of the trans- carbene ligand is significantly shorter (185(3) pm) than that of the cis-carbene ligand (208(3) pm).     

A ruthenium(II)–porphyrin–carbene complex with a weakly bonded methanol ligand

The title di­phenyl­carbene porphyrin complex (di­phenyl­carbenyl‐κC)(methanol‐κO)(5,10,15,20‐tetra‐p‐tolyl­por­phy­rin­ato‐κ⁴N)ruthenium(II) methanol solvate, [Ru­(C₁₃H₁₀)(C₄₈H₃₆N₄)(CH₄O)]·CH₄O, has a six‐coordinate Ru atom with a methanol mol­ecule as the second axial ligand. The carbene fragment is slightly distorted from an ideal sp² configuration, with a C(phenyl)—C(carbene)—C(phenyl) angle of 112.2 (3)°. The Ru—C bond length of 1.845 (3) Å is comparable with other carbene complexes. The two phenyl rings of the carbene ligand are perpendicular to the carbene plane. Methanol solvate mol­ecules link the methanol ligands of adjacent porphyrin complexes via hydrogen bonds.     

Komplexe mit kohlenstoffsulfiden und -seleniden als liganden: IV. Ein- und zweikernige rhodium—CS2-komplexe und kristallstruktur eines RhSCSC-heterocyclus

The complexes C₅H₅Rh(PMe₃)CS₂(II) and C₅H₅Rh(PMe₂Ph)CS₂(III) are formed in excellent yields in the reaction of C₅H₅Rh(C₂H₄)PR₃(PR₃ = PMe₃, PMe₂Ph) with CS₂ in benzene. The CS₂ ligand in II and III is dihapto-bonded and at least in III is rigid. II reacts with Cr(CO)₅THF and C₅H₅Mn(CO)₂THF to give the binuclear complexes C₅H₅(PMe₃)Rh(SCS)Cr(CO)₅ (IV) and C₅H₅- (PMe₃)Rh(SCS)Mn(CO)₂C₅H₅ (V) in which the CS₂ molecule bridges two different metal atoms. In the reaction of C₅H₅Rh(C₂H₄)PMe₃ and CS₂ under certain conditions a second product of C₅H₅Rh(PMe₃)C₂S₄ (VI) is formed. The cyrstal structure shows that in this complex a five-membered RhSCSC heterocyclic ring is present.     

Reactions of coordinated molecules: XLIX. Carboncarbond bond formation between the donor atoms of adjacent acyl and alkenyl ligands

When the ferraenolate anion, (η-C₅H₅)(CO)₂FeC(O)CH₂⁻, is treated sequentially with methyllithium/TMEDA and benzoyl chloride, the known η³-allyl complex, (η-C₅H₅)(OC)Fe{η³-CH₂C[OC(O)Ph]C[OC(O)Ph](CH₃}, is isolated in 36% yield. When the neutral alkenyl complexes, (η-C₅H₅)(CO)₂Fe[C(Me)CH₂] and (η-C₅H₅)(OC)₂Fe{C(OMe)CH₂], were treated sequentially with methyllithium and benzoyl chloride, the η³-allyl complexes, (η-C₅H₅)(OC)Fe{η³-CH₂C(Me)C[OC(O)Ph](Me) and (η-C₅H₅)(OC)Fe{η³-CH₂C(OMe)C[OC(O)Ph](Me) are isolated in 8 and 11% yield, respectively. These η³-allyl ligands are presumably formed via CC coupling of the donor atoms of the formal acyl and alkenyl ligands in the intermediate complexes.     

(Cycloheptatrienyl)hydridotungsten Complexes

Carbonyl(cycloheptatrienyl)iodo(phosphorus donor)tungstens ([WI(C₇H₇)(CO)L]; L = P(OMe)₃, 1a ; L = P[O(i-Pr)]₃, 1b ; L = PPh₃, 1c ) were prepared from dicarbonyl(cycloheptatrienyl)iodotungsten ([WI(C₇H₇)(CO)₂)] via a carbonyl-substitution process. Similarly, bromocarbonyl(phosphorus donor)(1,2,4,6-tetramethylcycloheptatrienyl)tungstens ([WBr(Me₄C₇H₃)(CO)L]; L = P(OMe)₃, 6a ; L = P[O(i-Pr)]₃, 6b ; L = PPh₃, 6c ) were obtained from the reaction of bromodicarbonyl(1,2,4,6)-tetramethylcycloheptatrienyl)tungsten ([WBr(Me₄C₇H₃)(CO)₂]; 4 ) with L. The reduction of 1a - c , 4 , and 6a , b with sodiumdihydridobis(2-methoxyethoxy)aluminium in toluene led to stable hydrido complexes [WH(R₄C₇H₃)(CO)L] (R = H, L = P(OMe)₃, 2a ; R = H, L = P[O(i-Pr)]₃, 2b ; R = H, L = PPh₃, 2c ; R = Me, L = P(OMe)₃, 7a ; R = Me, L = P[O(i-Pr)]₃, 7b ; R = Me, L = CO, 7d ). Complexes 2a and 7b were characterized by X-ray structure analyses.     

Aqua(dipicolinato‐κ3O,N,O′)(1H‐imidazole‐κN3)(1,10‐phenanthroline‐N,N′)manganese(II)

In the title compound, [Mn(C₇H₃NO₄)(C₃H₄N₂)(C₁₂H₈N₂)(H₂O)], the Mn^II centre is surrounded by one bidentate phenanthroline ligand [Mn—N = 2.383 (3) and 2.421 (3) Å], one tridentate dipicolinate ligand [Mn—N = 2.300 (3) Å, and Mn—O = 2.300 (2) and 2.357 (2) Å], one monodentate imidazole ligand [Mn—N = 2.238 (3) Å] and one water molecule [Mn—O = 2.157 (3) Å]. It displays a distorted pentagonal‐bipyramidal geometry, with neighbouring angles within the equatorial plane ranging from 68.05 (9) to 77.48 (10)°. Intermolecular O—H...O hydrogen bonds link the molecules into infinite chains. The chains are crosslinked by hydrogen bonds involving the carboxyl O atoms of the dipicolinate ligand and the protonated imidazole N atom, leading to an infinite two‐dimensional network sheet packing mode. The complete solid‐state structure can be described as a three‐dimensional supramolecular framework, stabilized by these intermolecular hydrogen‐bonding interactions and π–π stacking interactions involving the phenanthroline rings.     

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.     

Basische Metalle. XXIV [1]. Ein- und zweikernige Cobaltthiolato-Komplexe aus Disulfiden. Spaltung einer S–S-Bindung durch eine Metall-Base

Basic metals. XXIV. Mono- and dinuclear cobaltthiolato complexes obtained from disulfides. Splitting of a S? S bond by a metal base The dinuclear complex C₅H₅(PMe₃)Co(μ-CO)₂Mn(CO)C₅H₄Me ( 3 ) reacts with the disulfides S₂R₂ (R ? Ph, CH₂Ph) by splitting of the sulfur-sulfur bond to form C₅H₅(PMe₃)Co(SR)₂ ( 4, 5 ). From 3 and S₂Me₂ a mixture of C₅H₅(PMe₃)Co(SMe)₂ ( 6 ) and [C₅H₅Co(μ-SMe)]₂ ( 7 ) is obtained. The synthesis of C₅H₅(PMe₃)Co(SCF₃)₂ ( 8 ) succeeds by treating 3 with N(SCF₃)₃. Whereas the reactions of 4 and 5 with MeI lead to the complex C₅H₅(PMe₃)CoI₂ ( 9 ), the dinuclear complex [C₅H₅(PMe₃)Co(μ-SPh)]₂(BF₄)₂ ( 11 ) is formed from 4 and [OMe₃]BF₄. The reactions of 11 with L = PMe₃ and P(OMe)₃ produce the compounds [C₅H₅Co(PMe₃)(L)SPh]BF₄ ( 12, 13 ), which react with [OMe₃]BF₄ to yield [C₅H₅Co(PMe₃)(L)(MeSPh)](BF₄)₂ ( 14, 15 ).     

Synthesis and 197Au-Mössbauer spectroscopic studies of dihalo(pentafluorophenyl)(bidentate ligand)gold(III) complexes

Addition of a bidentate ligand (LL = 1,10-phenanthroline, o-phenylenebis(dimethylarsine)) to solutions of Au(C₆F₅)X₂(tht) (X = Cl, Br; tht = tetrahydrothiophene) leads to potentially five-coordinate gold(III) derivatives. ¹⁹⁷Au Mössbauer spectroscopy points, however, to four-coordinate square-planar complexes with a weak penta-coordination in the phen-containing derivatives. The complexes react with AgClO₄ to give four-coordinate cationic complexes of the types [Au(C₅F₅)X(LL)]ClO₄ or [Au(C₆F₅)(PPh₃)(LL)](ClO₄)₂.     

Zur reaktion von metall-koordiniertem kohlenmonoxid mit yliden: XII. Eisenkomplexe mit η1-koordinierter vinylgruppe: spontane zweif achmethylierung des β-kohlenstoffs mit methyliodid oder methylfluorsulfonsäureerster

The reaction of vinyl complexes Cp(CO)(R₃P)FeC(OMe)CH₂ (R  Me, R  Ph) with the methylating reagents MeX (X  OSO₂F, I) in the molar ratio 1/1 affords a mixture of the carbene complexes [Cp(CO)(R₃P)FeC(OMe)R]X (R  Me, Et, i-Pr). Their formation is explained via a series of acid/base equilibria established between vinyl and carbene complexes.     

Structural studies on osmium carbonyl hydrides: XXXI. Crystal and molecular structure of CpWOs3(CO)9(μ-H)(μ-O)(μ-CHCH2C6H4Me), a hydrido-alkylidene produced by hydrogenation of a μ3-alkylidyne

The complex CpWOs₃(CO)₉(μ-H)(μ-O)(μ-CHCH₂C₆H₄Me), previously prepared by hydrogenation of CpWOs₃(CO)₉(μ-O)(μ₃-CCH₂C₆H₄Me), has been subjected to a single-crystal X-ray diffraction study. The complex crystallizes in the non-centrosymmetric monoclinic space group Cc(C_s⁴; No. 9) with a 14.1510(27), b 13.9257(22), c 13.3179(19) Å, β 92.023(13)°, V 2622.8(7) ų and D(calcd) 3.06 g cm^?3 for Z = 4 and mol. wt. 1206.8. Single-crystal X-ray diffraction data were collected with a Syntex P2₁ automated four-circle diffractometer and the structure was refined to R 3.5% for all 2476 independent observations (Mo-K_α radiation, 2θ = 4.5–40.0°) and R 3.4% for those 2430 data with | F₀| > 3.0σ(| F₀|). The molecule contains a tetrahedral WOs₃ core associated with 60 valence electrons. Each osmium atom is associated with three terminal carbonyl ligands and the tungsten atom is linked to an η⁵-C₅H₅ ligand. In addition, the μ-oxo ligand is involved in a WO: → Os bridge (in which WO(B) 1.737(17), Os(3)← :O(B) 2.167(16) Å and WO(B)Os(3) 96.0(7)°), the μ-hydride ligand spans the Os(1)Os(3) linkage and the μ-CHCH₂C₆H₄Me ligand bridges the WOs(2) linkage (WC(1) 2.068(26) and Os(2)C(1) 2.281(26) Å).     

Electron‐Rich Diferrous–Phosphane–Thiolates Relevant to Fe‐only Hydrogenase: Is Cyanide “Nature's Trimethylphosphane”?

The two‐step one‐pot oxidative decarbonylation of [Fe₂(S₂C₂H₄)(CO)₄(PMe₃)₂] ( 1 ) with [FeCp₂]PF₆, followed by addition of phosphane ligands, led to a series of diferrous dithiolato carbonyls 2 – 6 , containing three or four phosphane ligands. In situ measurements indicate efficient formation of 1 ²⁺ as the initial intermediate of the oxidation of 1 , even when a deficiency of the oxidant was employed. Subsequent addition of PR₃ gave rise to [Fe₂(S₂C₂H₄)(μ‐CO)(CO)₃(PMe₃)₃]²⁺ ( 2 ) and [Fe₂(S₂C₂H₄)(μ‐CO)(CO)₂(PMe₃)₂(PR₃)₂]²⁺ (R=Me 3 , OMe 4 ) as principal products. One terminal CO ligand in these complexes was readily substituted by MeCN, and [Fe₂(S₂C₂H₄)(μ‐CO)(CO)₂(PMe₃)₃(MeCN)]²⁺ ( 5 ) and [Fe₂(S₂C₂H₄)(μ‐CO)(CO)(PMe₃)₄(MeCN)]²⁺ ( 6 ) were fully characterized. Relevant to the H_red state of the active site of Fe‐only hydrogenases, the unsymmetrical derivatives 5 and 6 feature a semibridging CO ligand trans to a labile coordination site.