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.     

Bis(cyclopentadienyl)methan-verbrückte Zweikernkomplexe. VIII. Zweikernige Cobaltkomplexe mit dem Dianion des Bis(cyclopentadienyl)methans und des Bis(tetramethylcyclopentadienyl)dimethylsilans als Brückenliganden

Bis(cyclopentadienyl)methane-bridged Dinuclear Complexes. VIII. Dinuclear Cobalt Complexes with the Dianion of Bis(cyclopentadienyl)methane and Bis(tetramethylcyclopentadienyl)dimethylsilane as Bridging Ligands The dinuclear cobalt complex [CH₂(C₅H₄)₂][Co(CO)₂]₂ ( 4 ) which is obtained from [Co(CO)₄I] ( 2 ) and Li₂[CH₂(C₅H₄)₂] ( 3 ) in 75% yield reacts with PMe₃, PiPr₃, P₂Me₄, Me₂PCH₂CH₂PMe₂ and (EtO)₂POP(OEt)₂, to the compounds 5–9 substituting one CO ligand per cobalt atom. Oxidative addition of CH₃I to [CH₂(C₅H₄)₂][Co(CO)(PMe₃)]₂ ( 5 ) leads to the formation of the dinuclear cobalt(III) complex [CH₂(C₅H₄)₂][Co(COCH₃)(PMe₃)I]₂ ( 11 ). The reaction of 4 with iodide generates [CH₂(C₅H₄)₂][Co(CO)I₂]₂ ( 12 ) which with PMe₃, P(OMe)₃, P(OiPr)₃, and CNMe reacts under CO substitution to [CH₂(C₅H₄)₂][Co(L)I₂]₂ ( 13–16 ) and with PMe₂H to {[CH₂(C₅H₄)₂][Co(PMe₂H)₃]₂}I₄ ( 17 ). The electrophilic addition reactions of NH₄PF₆ and CH₃I to [CH₂(C₅H₄)₂][Co(PMe₃)₂]₂ ( 20 ) produce the complex salts {[CH₂(C₅H₄)₂][CoR(PMe₃)₂]₂}X₂ ( 21 : R = H; 22 : R = CH₃). From 22a (X = I) and LiCH₃ the dinuclear tetramethyldicobalt compound [CH₂(C₅H₄)₂] · [Co(CH₃)₂(PMe₃)]₂ ( 23 ) is obtained which further reacts, via the intermediate 24 , to the chiral complex {[CH₂(C₅H₄)₂] · [CoCH₃(PMe₃)P(OMe)₃]₂}(PF₆)₂ ( 25 ). The reaction of 20 with C₂(CN)₄ and E- or Z-C₂H₂(CO₂Me)₂ gives the olefin(trimethylphosphine) cobalt(I) derivatives 26 und 27 . The synthesis of the dinuclear compounds 31–38 with [Me₂Si(C₅Me₄)₂]^2? as the bridging unit is also described.     

Derivate des borabenzols: XVI. (Borinato)(cyclobutadien)cobalt-komplexe mit tetramethyl- und tetraphenylcyclobutadien-liganden. Synthese,elektrophile aromatische substitution und ringgliedsubstitution am borinato-liganden

The preparation of (borinato)(cyclobutadiene)cobalt complexes from the reactions of Co(C₅H₅BR)(1,5-C₈H₁₂) with acetylenes C₂R′₂ and of [C₄(CH₃)₄]Co(CO)₂I with Tl(C₅H₅BR) (R,R′ = CH₃, C₆H₅) is described.In electrophilic substitution reactions Co(C₅H₅BCH₃)[C₄(CH₃)₄] (IVa) is more reactive than ferrocene. CF₃CO₂D effects H/D-exchange in the α-position of the borabenzene ring within a few minutes at ambient temperature and in the γ-position within less than four hours Friedel-Crafts acetylation with CH₃COCl/AsCl₃ in CH₂Cl₂ affords the 2-acetyl and the 2,6-diacetyl derivative of IVa. With the more active catalyst AlCl₃, ring-member substitution is effected to give cations [Co(arene)C₄(CH₃)₄]⁺ (arene = C₆H₅CH₃, 2-CH₃C₆H₄COCH₃). Vilsmeier formylation gives the 2-formyl derivative of IVa. The acyl derivatives Co(2-R¹CO-6-R²C₅H₃BCH₃)[C₄(CH₃)₄] (R¹ = CH₃, R² = H, CH₃CO and R¹ = R² = H) transform to the corresponding cations [Co(ortho-R¹R²C₆H₄)C₄(CH₃)₄]⁺ in superacidic media. The mechanistic relationship between acylation and ring-member substitution is discussed in detail.     

Bis(cyclopentadienyl)methan-verbrückte Zweikernkomplexe: II. Synthese und Reaktionen ringverbrückter Cobalt-Zweikernkomplexe mit zwei nucleophilen Metallzentren

The dinuclear cobalt complex [CH₂(C₅H₄)₂][Co(PMe₃)₂]₂ (2), which is prepared from CoCl(PMe₃)₃ and [CH₂(C₅H₄)₂]Li₂, reacts with NH₄PF₆ and CH₃I to form the protonated and methylated dications {[CH₂(C₅H₄)₂][CoR(PMe₃)₂]₂}²⁺ (R = H, CH₃). Treatment of {[CH₂(C₅H₄)₂][CoCH₃(PMe₃)₂]₂}I₂ (4) with LiCH₃ affords the neutral compound [CH₂(C₅H₄)₂][Co(CH₃)₂(PMe₃)]₂ (5). Ligand substitution of [CH₂(C₅H₄)₂][Co(CO)₂]₂ (6) with P₂Me₄ and 1,2-C₂H₄(PMe₂)₂(dmpe) gives the doubly-bridged complexes [CH₂(C₅H₄)₂][Co₂(CO)₂(μ-P₂Me₄)] (7) and [CH₂(C₅H₄)₂][Co₂(CO)₂(μ-dmpe)] (8), respectively. Similarly, [CH₂(C₅H₄)₂][Co-(CO)(PMe₃)]₂ (9) is obtained from the reaction of 6 with PMe₃. Oxidation of 6 with iodine gives [CH₂(C₅H₄)₂][Co(CO)I₂]₂ (11) which is transformed via {[CH₂(C₅H₄)₂][Co(PMe₂H)₃]₂}I₄ (12) into the triply-bridged cobalt(II) complex [CH₂(C₅H₄)₂][CO₂(μ-PMe₂)₂] (13).     

Synthesis of Cobalt-Tin and -Lead Tetrylidynes—Reactivity Study of the Triple Bond

Tetrylidynes [TbbSn≡Co(PMe₃)₃] ( 1 a ) and [TbbPb≡Co(PMe₃)₃] ( 2 ) (Tbb=2,6-[CH(SiMe₃)₂]₂-4-(t-Bu)C₆H₂) are accessed for the first time via a substitution reaction between [Na(OEt₂)][Co(PMe₃)₄] and [Li(thf)₂][TbbEBr₂] (E=Sn, Pb). Following an alternative procedure the stannylidyne [Ar*Sn≡Co(PMe₃)₃] ( 1 b ) was synthesized by hydrogen atom abstraction using AIBN from the paramagnetic hydride complex [Ar*SnH=Co(PMe₃)₃] ( 4 ) (AIBN=azobis(isobutyronitrile)). The stannylidyne 1 a adds two equivalents of water to yield the dihydroxide [TbbSn(OH)₂CoH₂(PMe₃)₃] ( 5 ). In reaction of the stannylidyne 1 a with CO₂ a product of a redox reaction [TbbSn(CO₃)Co(CO)(PMe₃)₃] ( 6 ) was isolated. Protonation of the tetrylidynes occurs at the cobalt atom to give the metalla-stanna vinyl cation [TbbSn=CoH(PMe₃)₃][BAr^F₄] ( 7 a ) [Ar^F=C₆H₃-3,5-(CF₃)₂]. The analogous germanium and tin cations [Ar*E=CoH(PMe₃)₃][BAr^F₄] (E=Ge 9 , Sn 7 b ) (Ar*=C₆H₃(2,6-Trip)₂, Trip=2,4,6-C₆H₂iPr₃) were also obtained by oxidation of the paramagnetic complexes [Ar*EH=Co(PMe₃)₃] (E=Ge 3 , Sn 4 ), which were synthesized by substitution of a PMe₃ ligand of [Co(PMe₃)₄] by a hydridoylene (Ar*EH) unit.     

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 ).     

Komplexe mit kohlenstoffsulfiden und -seleniden als liganden: XIII. Reaktionen der metall-basen C5H5M(PR3)2 und C5H5M(PR3)L (M = Co,Rh) mit CSSe und CSe2: synthese und eigenschaften von cyclopentadienylcobalt- und rhodium- komplexen mit CS,CSe, CSSe,CSe2, CSSe22−, CSe32−, C2S2Se22−- und C2Se42−- als liganden

C₅H₅Co(PMe₃)₂ (I) reacts with CSSe to give C₅H₅Co(η²-CSSe)PMe₃ (IV) and C₅H₅Co(CS)PMe₃ (V). The thiocarbonyl complex V is formed in an almost quantitative yield by Se abstraction from IV and PPh₃. The corresponding compounds C₅H₅Co(CS)PMe₂Ph (VII) and C₅H₅Co(CS)[P(OMe)₃] (VIII) are obtained as the main products directly from CSSe and C₅H₅Co(PMe₂Ph)₂ or C₅H₅Co[P(OMe)₃]₂. In the reaction of C₅H₅Co(PR₃)₂ (PR₃ = PMe₃, PMe₂Ph) with CSe₂, the carbon diselenide complexes C₅H₅Co(η²-CSe₂)PMe₃ (XI) and C₅H₅Co(η²-CSe₂)PMe₂Ph (XIV) are formed. XI reacts with PPh₃ to give C₅H₅Co(CSe)PMe₃ (XII). Cyclopentadienylcobalt compounds containing CSSe₂^2?, CSe₃^2? and C₂Se₄^2? as ligands are isolated as side products in the; reactions of C₅H₅Co(PR₃)₂ and C₅H₅Co(CO)PR₃ (PR₃ = PMe₃, PMe₂Ph) with CSSe and CSe₂, respectively. Displacement of ethylene from C₅H₅Rh(C₂H₄)PMe₃ by CSSe yields the complex C₅H₅Rh(η²-CSSe)PMe₃ (XVIII) which reacts with PPh₃ to give C₅H₅Rh(CS)PMe₃ (XIX) and with excess CSSe to give C₅H₅RhC₂S₂Se₂(PMe₃) (XX). Besides small amounts of C₅H₅Rh(η²CSSe)PMe₂Ph (XXI), the corresponding metallaheterocycle C₅H₅RhC₂S₂Se₂(PMe₂Ph) (XXII) is formed as the main product from C₅H₅Rh(C₂H₄)PMe₂Ph and CSSe.     

Basische metalle : XXXVII. Zur reaktivität der ethylen(hydrido)rhodium-komplexe [C5H5RhH(C2H4)PR3]X gegenüber nucleophilen: insertion versus substitution

The complex [C₅H₅RhH(C₂H₄)PMe₃]BF₄ (I) reacts with NaF and NaCN by deprotonation to give C₅H₅Rh(PMe₃)C₂H₄ but with NaCl, NaBr and NaI the ethylrhodium compounds C₅H₅RhC₂H₅(PMe₃)X (II–IV) are obtained. The reactions of I with CO and PPrⁱ₃ yield the BF₄ salts of the cations [C₅H₅RhH(CO)PMe₃]⁺ and [C₅H₅RhH(PPrⁱ₃)PMe₃]⁺ (V, VI), respectively, from which the uncharged complexes C₅H₅Rh(CO)PMe₃ (VII) and C₅H₅Rh(PPRⁱ₃)PMe₃ (VIII) are prepared. The carbonyl compound VII is also accessible either from C₅H₅Rh(CO)₂ and PMe₃ or from C₅H₅Rh(PMe₃)₂ and CO. The reaction of I with ethylene leads to the BF₄ salt of the cation [C₅H₅RhC₂H₅(PMe₃)C₂H₄]⁺ (X) which on treatment with PMe₃ forms the complex [C₅H₅RhC₂H₅(PMe₃)C₂H₄PMe₃]BF₄ (XI). The compound [C₅H₅RhH(C₂H₄)PPrⁱ₃]BF₄ (XII) reacts with NaI by insertion to yield C₅H₅RhC₂H₅(PPrⁱ₃)I (XIII) whereas with PPrⁱ₃ the salt [C₅H₅RhH(PPrⁱ₃)₂]BF₄ (XIV) is produced. The bis(triisopropylphosphine) complex C₅H₅Rh(PPrⁱ₃)₂ (XVI) is obtained from XIV and NaH.     

Basische metalle : XXXVI. Die synthese stabiler hydrido(olefin)rhodium-komplexe und von[C5H5Rh(PMe3)(η3-CH3CHC6H5)]PF6

The complexes C₅H₅Rh(PMe₃)C₂H₃R′ (R′  H, Me, Ph) and C₅H₅Rh(PR₃)C₂H₄(PR₃  PMe₂Ph, PPrⁱ₃) are prepared by reaction of[PMe₃(C₂H₃R/t')RhCl]₂ or [PR₃(C₂H₄)RhCl]₂ and TlC₅H₅, respectively. They react with HBF₄ in ether/propionic anhydride to form the BF₄ salts of the hydrido(olefin)rhodium cations [C₅H₅RhH(C₂H₃R′)PR₃]⁺(R  Me; R′  H, Me and R  Prⁱ; R′  H). From C₅H₅Rh(PMe₃)C₂H₃Ph and CF₃COOH/NH₄PF₆ the η³-benzyl complex [C₅H₅Rh(PMe₃)(η³-CH₃CHC₆H₅)]PF₆ is obtained. The reversibility of the protonation reactions is demonstrated by temperature-dependent NMR spectra and by deuteration experiments. The complexes C₅H₅Rh(PMe₃)C₂H₃R′ (R′  H, Ph) and C₅H₅Rh(PMe₂Ph)C₂H₄ react with CH₃I in ether to give the salts [C₅H₅RhCH₃(C₂H₃R′)PR₃]I which in THF or CH₃NO₂ yield the neutral compounds C₅H₅RhCH₃(PR₃)I.     

Local surrounding of cobalt(II) in dithiocarbamate complexes,their magnetic and spectral properties

[Co(S₂CNRR’)₂] complexes [R = R’ = CH₃, C₂H₅, C₃H₇, C₄H₉, or CH₂C₆H₅; RR’ = (CH₂)₅, (CH₂)₆, or (CH₂)₂O(CH₂)₂] were prepared via interaction of CoCl₂ with sodium dithiocarbamates in aqueous medium (pH 6–7). [Co(S₂CNRR’)₂] are low-spin compounds (μ_eff 2.19–2.45 μ_B) with distorted square-planar geometry of the CoS₄ coordination node. The Co-S bonds length is 2.22–2.26 Å, and the distance between cobalt and carbon atoms is 2.73–2.74 Å.     

Ethylen(hydrido)-metallkomplexe aus M(CH2)CH3-vorstufen: modellreaktionen für einen elementarschritt der fischer-tropsch-synthese

The compounds C₆Me₆Ru(Ch₃)₂, C₆H₆Os(CH₃)₂PMe₃ and C₅H₅Ir(CH₃)₂-Pprⁱ₃ react with [CPh₃]PF₆ in Ch₂Cl₂ to give the ethylene(hydrido)metal complexes [C₆Me₆RuH(C₂H₄)PR₃]PF₆, [C₆H₆OsH(C₂H₄)PMe₃]PF₆ and [C₅H₅IrH(C₂H₄)PPrⁱ₃]PF₆, respectively. Treatment of C₆Me₆RuCH₃(C1)PMe₃ with [CPh₃]PF₆ leads to cleavage of the RuCH₆ bond instead of hydride elimination; in the presence of PMe₂Ph the compound [C₆Me₆RuCl(PMe₂Ph)PMe₃]PF₆ is obtained. The reaction of C₅H₅RhCH₂OMe(PMe₃)CH₃ with HBF₄ gives [C₅H₅RhH(C₂H₄)PMe₃]BF₄ and methanol. It is assumed that the formation of the ethylene(hydrido)metal complexes always occur via a M(CH₂)CH₃ intermediate, radical intermediates not being observed. The crystal structure of [C₆Me₆RuH(C₂H₄)PPh₃]PF₆ has been determined. The cation of 1.50 Å. The CC distance in the ethylene ligand is 1.41(1) Å and thus is significantly longer than in the free olefin.     

Cycloadditionsreaktionen von Organometall-Komplexen : XV. [2 + 31- und [2 + 1]-Cycloadditionsreaktionen von Carbonylrhodium- und Carbonylcobalt-Komplexen mit Nitriloxiden und Aziden. Die Kristall- und Molekülstruktur von C5H5(PPr3) (C6H5)

The reaction of C₅H₅Rh(CO)(PⁱPr₃) (1] which is prepared from C₅H₅Rh(CO)₂ and neat P¹Pr₃, with the nitriloxides 2-RC₆H₄CNO (R = H, Cl) leads to the formation of the metallaheterocycles C₅H₅(P¹Pr₃) ) (2, 3) in 90–95% yield. Compound 1 reacts with tosylazide to give the C,N-bound isocyanate complex C₅ H₅(PⁱPr₃)Rh(η²-TosN=C=O) (6). Analogously, on treatment of C₅Me₅Co(CO)(PMe₃) with phenylazide the phenylisocyanate derivative C₅Me₅(PMe₃)Co(η²-PhN=C=O) (7) is formed. Protonation of 7 with CF₃CO ₂H affords the non-ionic carbamoylcobalt complex C₅Me₅(PMe₃)Co[C(O)NHPh](O₂CCF₃) (8). The X-ray structural analysis of 2 reveals the presence of an almost planar heterocycle in which the two Rh-C distances differ by 0.045 Å     

Synthesis and reactions of a nucleophilic bis(μ-dimethylphosphido)dicobalt complex. The crystal and molecular structure of [C5H5Co(μ-PMe2)]2 and [(C5H5Co)2(μ-H)(μ-PMe2)2]BPh4

The bis(μ-dimethylphosphido)dicobalt complex [C₅H₅Co(μ-PMe₂)]₂ (II) has been prepared from Co(C₅H₅ and PMe₂H on almost quantitative yield. It has also been made by reduction of [C₅H₅Co(PMe₂H)₃]I₂ (IV) with NaH and from the reaction of [C₅H₅(PMe₃)Co(μ-CO)₂Mn(CO)C₅H₄Me] with PMe₂H. Protonation of II with CF₃CO₃H in the presence of NH₄PF₆ produces the PF₆^? salt of the (μ-hydrido)dicobalt cation [(C₅H₅Co)₂(μ-H)(μ-PMe₂)₂]⁺ (V) which reacts with aqueous NaOH to give II. Similar treatment of [C₅H₅Co(μ-SMe]₂ with CF₃CO₂H/NH₄PF₆ leads to the formation of [(C₅H₅Co)₂(μ-SMe)₃]PF₆ (VI). The nucleophilic character of complex II has also been demonstrated in the reaction with SO₂, which gives [(C₅H₅Co)₂ (μ-PMe₂)₂(μ-SO₂)] (VII). The crystal and molecular structures of II, the corresponding bis(μ-diphenylphosphido) compound [C₅H₅Co(μ-PPh₂)]₂ (III) and the BPh₄^? salt of V have been determined. In both neutral complexes the Co₂P₂ cores are similarly puckered, as reflected in the dihedral angle between the CoP₂ and P₂Co′ planes of 108.1 and 105.0° for R = Me and Ph, respectively. The CoCo bond length and the PP interatomic separations are essentially identical for both dimers. The CoCo bond length in V, 2.517(1) Å, is lower than that in II, 2.542(2) Å. The only obvious structural variation between the unprotonated and the protonated species is the large difference in the degree of canting of the C₅H₅ rings with respect to each other. The angles between the C₅(ring)-centroid and the CoCo line are ca. 150 and 167° in II and V, respectively, which reflects the influence of the bridging hydride ligand in the cationic complex.     

Addition des O'Donnell Reagenzes [Ph2C=NCHCO2Me]– an π-koordinierte,ungesättigte Kohlenwasserstoffe in [(C6H7)Fe(CO)3]+, [(C7H9)Fe(CO)3]+, [(C7H7)M(CO)3]+ (M = Cr,Mo) und [(C2H4)Re(CO)5]+. α-Aminosäuren mit metallorganischen Seitenketten

Metal Complexes of Biologically Important Ligands. CXVII [1] Addition of the O'Donnell Reagent [Ph₂C=NCHCO₂Me]^– to Coordinated, Unsaturated Hydrocarbons of [(C₆H₇)Fe(CO)₃]⁺, [C₇H₉Fe(CO)₃]⁺, [(C₇H₇)M(CO)₃]⁺ (M = Cr, Mo), and [(C₂H₄)Re(CO)₅]⁺. α-Amino Acids with Organometallic Side Chains The addition of [Ph₂C=NCHCO₂Me]^– to [(C₆H₇)Fe(CO)₃]⁺, [(C₇H₉)Fe(CO)₃]⁺, [(C₇H₇)M(CO)₃]⁺ (M = Cr, Mo) and [(C₂H₄)Re(CO)₅]⁺ gives derivatives of α-amino acids with organometallic side chains. The structure of [(η⁴-C₆H₇)CH(N=CPh₂)CO₂Me]Fe(CO)₃ was determined by X-ray diffraction. From the adduct of [Ph₂C=NCHCO₂Me]^– and [(C₇H₇)Mo(CO)₃]⁺ the Schiff base of a new unnatural α-amino acid, Ph₂C=NCH(C₇H₇)CO₂Me, was obtained.     

Bis(cyclopentadienyl)methan-verbrückte Zweikernkomplexe,V. Heteronukleare Co/Rh-, Co/Ir-, Rh/Ir- und Ti/Ir-Komplexe mit dem Bis(cyclopentadienyl)methan-Dianion als Brückenliganden

Bis(cyclopentadienyl)methane-bridged Dinuclear Complexes, V^[1]. – Heteronuclear Co/Rh-, Co/Ir-, Rh/Ir-, and Ti/Ir Complexes with the Bis(cyclopentadienyl)methane Dianion as Bridging Ligand^* The lithium and sodium salts of the [C₅H₅CH₂C₅H₄]^- anion, 1 and 2 , react with [Co(CO)₄I], [Rh(CO)₂Cl]₂, and [Ir(CO)₃Cl]n to give predominantly the mononuclear complexes [(C₅H₅-CH₂C₅H₄)M(CO)₂] ( 3, 5, 7 ) together with small amounts of the dinuclear compounds [CH₂(C₅H₄)₂][M(CO)₂]₂ ( 4, 6, 8 ). The ¹H- and ¹³C-NMR spectra of 3, 5 , and 7 prove that the CH₂C₅H₅ substituent is linked to the π-bonded ring in two isomeric forms. Metalation of 5 and 7 with nBuLi affords the lithiated derivatives 9 and 10 from which on reaction with [Co(CO)₄I], [Rh(CO)₂Cl]₂, and [C₅H₅TiCl₃] the heteronuclear complexes [CH₂(C₅H₄)₂][M(CO)₂][M′(CO)₂] ( 11–13 ) and [CH₂(C₅H₄)₂]-[Ir(CO)₂][C₅H₅TiCl₂] ( 17 ) are obtained. Photolysis of 11 and 12 leads almost quantitatively to the formation of the CO-bridged compounds [CH₂(C₅H₄)₂][M(CO)(μ-CO)M′(CO)] ( 14, 15 ). According to an X-ray crystal structure analysis the Co/Rh complex 14 is isostructural to [CH₂(C₅H₄)₂][Rh₂(CO)₂(μ-CO)] ( 16 ).     

Basische metalle: LIII. Ruthenium- und osmium-komplexe mit dem dimethylphosphinomethanid-anion als liganden

The reduction of trans-RuCl₂(PMe₃)₄ with Na/Hg and of trans-OsCl₂(PMe₃)₄ with sodium in the presence of catalytic amounts of naphthalene gives the complexes RuH(η²-CH₂PMe₂)(PMe₃)₃ (III) and OsH(η²-CH₂PMe₂PMe₂), (IV) in good yields. An equilibrium with the metal(0) isomers [M(PMe₃)₄] cannot be detected by NMR spectroscopy. III and IV react with dihalomethanes CH₂X₂ (X = Cl, Br, I) and CH₃I to form mixtures of the dimethylphosphinomethanide complexes MX(η²-CH₂PMe₂)(PMe₃)₃ and the compounds MX₂(PMe₃)₄. The reactions of III and IV with the Brönsted acids HCl, HBr, CF₃CO₂H and HC₂Ph lead (with exception of M = Ru and X = C₂Ph) to the complexes cis-MX₂(PMe₃)₄. The hydrolysis of IV gives the hydrido(hydroxy) compound cis-OsH(OH)(PMe₃)₄, which has been characterized by ¹H, ³¹P NMR and mass spectroscopy. The synthesis of the complex cis-Os(CH₃)₂(PMe₃)₄ is also described; the conversion into the ethylene(hydrido)metal cation [OsH(C₂H₄)(PMe₃)₄]⁺ failed.     

Synthese und reaktivität von dienylmetall-verbindungen: XXI. Cyclopentadienylnickel-komplexemit sterisch anspruchsvollen phosphan-liganden

Bulky phosphanes PR₃ (R = C₆H₁₁, iC₃H₇, t-C₄H₉, C₆H₄CH₃-o) stabilize complexes of type [C₅H₅Ni(PR₃)L]BF₄ (L=S(CH₃)₂, (CH₃)₃PS), from which [C₅H₅Ni(PR₃)₂]⁺ cations are obtained. Iodide replaces the sulfur ligands to yield neutral C₅H₅Ni(PR₃)I compounds. No stable [C₅H₅Ni(PR₃)]⁺ cations could be obtained by iodide abstraction, but [C₅H₅Ni(PR₃)CO]⁺ cations were formed in the presence of carbon monoxide.     

Synthesis and properties of pentamethylmetallocene derivatives Cp*MCp (M = Ru, Fe). Crystal structure of the salt [CpRuC5Me4CH2+OC6H2(NO2)3-]

Photolysis of a solution of Cp*RuCp (1) in CF₃CO₂H generates salt [CpRu(C₅Me₄CH₂)]-(O₂CCF₃)(2 • O₂CCF₃). The reaction of compound 1 with oleum at 20 °C through the intermediate dication [η⁵-(CH₂C₅Me₄)Ru(μ:η⁵,ν⁵-C₅H₄C₅H₅)Ru(C₅Me₄CH₂)-η⁶]²⁺ leads to the triply charged cation η⁷CH₂)₂C₅Me₃Ru(μη⁵,η⁵-C₅H₄C₅H₄)Ru(C₅Me₄CH₂)-η⁶]³⁺. Synthesis of pentamethylmetallocene derivatives CpMC₅Me₄X (M = Ru, Fe; X = CHO, CH₂OH, CH₂An) has been accomplished. The reactions of 1-hydroxymethyl-2,3,4,5-tetramethylruthenocene with acids CF₃CO₂H, HBF₄, CF₃CO₂H/NaB[C₆H₃(CF₃)₂]₄, and picric acid C₆H₂(NO₂)₃OH afforded salts 2•X (X = CF₃CO₂, BF₄, B[C₆H₃(CF₃)₂]₄), and (2,3,4,5-tetram ethylruthenocenyl)methyl picrate [CpRu(C₅Me₄CH₂)-η⁶][(C₆H₂(NO₂)₃O] (2•C₆H₂(NO₂)₃O). Structure of the latter was characterized by single crystal X-ray diffraction.     

Basische metalle : XXXV. Neutrale rhodium-carbenoid-verbindungen und ihre umwandlung in kationische und neutrale rhodium-ylid-komplexe

The reaction of C₅H₅Rh(PMe₃)C₂H₄ or C₅H₅Rh(PMe₃)CO with CH₂I₂ affords the compound C₅H₅RhCH₂I(PMe₃)I from which stable cationic ylide-rhodium complexes [C₅H₅RhCH₂L(PMe₃)I]X (L = PPh₃, PPrⁱ₃, AsPh₃, SMe₂, NEt₃; X = I, PF₆) are prepared. In the presence of NEt₃, C₅H₅RhCH₂I(PMe₃)I also undergoes isomerisation to yield C₅H₅Rh(CH₂PMe₃)I₂. C₅H₅RhCH₂I(PMe₃)I reacts with NaOMe and NaSMe to give C₅H₅RhCH₂OMe(PMe₃)I and C₅H₅RhCH₂SMe(PMe₃)SMe, respectively.     

A cyclometallated iridium(III) dimethylphenylphosphine complex

[Ir(cod)Cl]₂ (cod = 1,5-cyclooctadiene) reacts with PMe₂Ph in CH₃CN to give the red cation [Ir(PMe₂Ph)₄]⁺. This complex in CH₃CN reacts with H₂ to give cis-[IrH₂(PMe₂Ph)₄]⁺, but on reflux for 6 h in the absence of H₂, it gives the first example of a cyclometallated PMe₂Ph complex fac-[IrH(PMe₂C₆H₄)(PMe₂Ph)₃]⁺, as shown by PMR spectroscopy and preliminary X-ray crystallographic data.