Synthesis,characterization and reactions of the transition metal halogenoalkyl carbocation complexes [Cp(CO)2M{η2-CH2CH(CH2)nX}]PF6 (n = 1–8, 10, M = Fe; n = 3, 4 M = Ru; X = Br,I)

The halogenoalkyl complexes [Cp(CO)₂M{(CH₂)_nX}] (n = 3–10, 12, M = Fe; n = 5, 6, M = Ru, X = Br, I) react with Ph₃CPF₆ in dry CH₂Cl₂ to give the corresponding carbocation complexes [Cp(CO)₂M{η²-(CH₂CH(CH₂)_n?2X}]PF₆ in high yields. NMR evidence indicates that the metals form metallacyclopropane type structures with the carbocation ligand. The reactions of some of the cationic complexes with NaI, PPh₃, Na[Cp(CO)₂Fe] and Et₃N are discussed. NaI and Na[Cp(CO)₂Fe] displace the halogeno-olefin, while PPh₃ adds at the β-CH^δ+ giving the unstable phosphonium adducts [Cp(CO)₂Fe{CH₂CH(PPh₃)(CH₂)_n?2X}]PF₆ which decompose to the halogeno-olefins and the cationic PPh₃ complex [Cp(CO)₂Fe(PPh₃)]⁺. Et₃N causes allylic deprotonation forming internal olefin complexes of the type [Cp(CO)₂Fe{CH₂CHCH(CH₂)_n?3X}]PF₆.     

Zur Reaktion von Metall-koordinierten Kohlenmonoxid mit Yliden XXII. Bis(diphenylphosphino)methanid-Eisen-Komplexe Cp(L)Fe(Ph2PCHPPh2) (L = CO,Me3P)

The reaction of [Cp(CO)(dppm)Fe]BF₄ (1a) with the phosphorus ylide Me₃PCH₂ yields the novel bis(phosphino)methanideiron complex Cp(CO)Fe(Ph₂PCHPPh₂) (2), which upon photolysis in the presnece of Me₃P is converted into Cp(Me₃P)Fe(Ph₂PCHPPh₂ (3). Reaction of 2 with MeOSO₂CF₃ gives a mixture of the iron salts [(Cp(CO)Fe(Ph₂PCR(R′)PPh₂)]CF₃SO₃ (R = R′ = H (1b), R = R′ = Me (6) and R = H, R′ = Me (syn/anti-4)).     

Reaction studies on some functionalized alkyl transition metal compounds and the crystal structure of [Cp(CO)3W{(CH2)3NO2}]

The reactions of the halogenoalkyl compounds [Cp(CO)₃W{(CH₂)_nX}] (Cp = η⁵-C₅H₅; n = 3-5; X = Br, I) and [Cp(CO)₂(PPhMe₂)Mo{(CH₂)₃Br}] with the nucleophiles Z = CN⁻ and gave compounds of the type [Cp(CO)₃W{(CH₂)_nZ}] for the tungsten compounds, whilst cyclic carbene compounds were obtained from the reactions of the molybdenum compound. The reactions of [Cp(CO)₃W{(CH₂)_nBr}] (n = 3, 4) and [Cp(CO)₂(PPhMe₂)Mo{(CH₂)₃Br}] with gave [Cp(CO)₃W{(CH₂)_nONO₂}] and [Cp(CO)₂(PPhMe₂)Mo{(CH₂)₃ONO₂}], respectively. The reaction of [Cp(CO)₃W{(CH₂)_nBr}] with AgNO₂ gave [Cp(CO)₃W{(CH₂)_nNO₂}]. In the solid state the complex [Cp(CO)₃W{(CH₂)₃NO₂}] crystallizes in a distorted square pyramidal geometry. In this molecule the nitropropyl chain deviates from the ideal, all-trans geometry as a result of short, non-hydrogen intermolecular N-O?O-N contacts. The reactions of the heterobimetallic compounds [Cp(CO)₃W{(CH₂)₃}ML_y] {ML_y = Mo(CO)₃Cp, Mo(CO)₃Cp^∗ and Mo(CO)₂(PMe₃)Cp; Cp^∗ = η⁵-C₅(CH₃)₅} with PPh₃ and CO were found to be totally metalloselective, with the ligand always attacking the metal site predicted by the reactions of the corresponding monometallic analogues above with nucleophiles. Thus the compounds [Cp(CO)₃W{(CH₂)₃}C(O)ML_z] {ML_z = Mo(CO)₂YCp, Mo(CO)₂YCp^∗ and Mo(CO)Y(PMe₃)Cp; Y = PPh₃ or CO} were obtained. Similarly, the reaction of [Cp(CO)₂Fe{(CH₂)₃}Mo(CO)₂(PMe₃)Cp] with CO gave only [Cp(CO)₂Fe{(CH₂)₃C(O)}Mo(CO)₂(PMe₃)Cp]. Hydrolysis of the bimetallic compound, [Cp(CO)₃W(CH₂)₃C(O)Mo(CO)(PPh₃)(PMe₃)Cp], gave the carboxypropyl compound [Cp(CO)₃W{(CH₂)₃COOH}]. Thermolysis of the compound [Cp(CO)₂Fe(CH₂)₃Mo(CO)₃(PMe₃)Cp] gave cyclopropane and propene, indicating that β-elimination and reductive processes had taken place.     

Übergangsmetall-substituierte phosphane,arsane und stibane: XXXVI. Diastereomere dreikernkomplexe mit verbrückenden dimethylarsino-, dimethylstibino- oder dimethylbismutino-einheiten

Interaction of the chiral organometallic Lewis bases Cp(CO)(Me₃P)Fe—EMe₂ (E = As, Sb, Bi) (1a–1c) with the norbornadiene metal complex (C₇H₈)Mo(CO)₄ yields the first examples of trinuclear complexes [Cp(CO)(Me₃P)Fe—EMe₂]₂Mo(CO)₄ (2a–2c), bearing two chiral metal atoms separated by a E—Mo—E-linkage. 2a–2c are generated as a mixture of two diastereomers (RS/SR, RR/SS), which gives rise to a resonance doubling in their ¹H and ³¹P NMR spectra. This phenomenon is not observed for the achiral, in part sterically more crowded derivatives [Cp(CO)₂Fe—SbMe₂]₂Mo(CO)₄ (4) and [Cp(CO)₂(Me₃P)Mo—EMe₂]₂Mo(CO)₄ (E = As, Sb (6a, 6b)), which excludes the existence of conformers resulting from restricted rotation about the FeE or MoE bond in the case of 2a–2c.     

Übergangsmetall-substituierte phosphane,arsane und stibane : XXIX. Metallierte arsane und stibane mit chiralem eisen-substituenten

The reaction of Cp(CO)₂FeEMe₂ (E  As, Sb, Bi) with Me₃P, Et₃P, Me₂PhP and (MeO)₃P leads to a CO/R₃P exchange and formation of the chiral derivatives Cp(CO)(R₃P)FeEMe₂. Cp(CO)[(MeO)₃P]FeEMe₂ rearranges already at room temperature to Cp(CO)[(Me₃E]FeP(O)(OMe)₂ which is transformed by (MeO)₃P to Cp(CO)[(MeO)₃P]FeP(O)(OMe)₂. The high nucleophilicity of the new organometallic Lewis bases is established by the easy conversion of Cp(CO)(Me₃P)FeSbMe₂ to [Cp(CO)(Me₃P)Fe(SbMe₃)]I with MeI, or to [Cp(CO)(Me₃P)FeSbMe₂Fe(CO)LCp]Hal (L  CO, Hal  Cl; L  Me₃P, Hal  Br) with Cp(CO)LFe-Hal, respectively. The new compounds are characterized by spectroscopy and elementary analyses.     

Dithiocarbene complexes derived from CS2 -bridged dinuclear complexes

Stable dithiocarbene complexes {CP(CO)₂FeC(SCH₃)[SML_n]}⁺ (ML_n = Re(CO)₅, Fe(CO)₂Cp) are formed when monodentate ferrodithiocarboxylate—metal complexes Cp(CO)₂FeC(S)[SM′L_n] (Cp  η⁵ -C₅H₅) are treated with CH₃SO₃CF₃.     

Synthese und reaktivität von silicium.übergangsmetall-komplexen: XVII. Ferrio-tris(dimethylamino)silane Cp(L)2FeSi(NMe2)3 (L = CO,Me3P): Synthese und abbau mit methyliodid

The reaction of Cp (CO)₂FeSiCl(NMe₂ (2) with LiNMe₂ yields the ferriotris(dimethylamino)silane Cp(CO)₂FeSi(NMe₂)₃ (3) in minor quantities. High yield of 3 is obtained by treatment of Cp(CO)₂FeSiBr₃ (5) with Me₂NH. Irradiation of 3 in the presence of Me₃P gives Cp(Me₃P)₂FeSi(NMe₂)₃ (7), which reacts with MeI to give the iron iodide Cp(Me₃P)₂FeI (8). A plausible mechanism for the conversion of 7 to 8 is formulated involving the intermediate formation of a cationic complex with trivalent silicon.     

A new reaction of [Cp((CO)2Fe(PPh2H)]PF6 with NaBH4 to give Cp(CO)(H)Fe(PPh2H) via Cp(CO)2FeH and PPh2H

[Cp((CO)₂Fe(PPh₂H)]PF₆ reacts with NaBH₄ to give the intermediates CpFe(CO)₂H and PPh₂H, which are then converted into Cp(CO)(H)Fe(PPh₂H). [Cp(CO)₂FeL]PF₆ (L = P(OMe)₃, P(OEt)₃ and P(OⁱPr)₃) reacts with NaBH₄ to give the product Cp(CO)(H)FeL directly without Cp(CO)₂FeH and L even being formed transiently. The proposed reaction mechanism is that H⁻ attacks th phosphorus atom to give a metallaphosphorane complex, followed by coupling between a Cp(CO)₂Fe fragment and H on the hypervalent phosphorus.     

Reactions of manganese π-acetylenic, η-vinylidenic,and η-allenylidenic complexes with Fe2(CO)9. Crystal and molecular structure of Cp(CO)2Mn(μ2-CCHCOOCH3)Fe(CO)4

The interaction between Cp(CO)₂Mn(CCHCOOMe) (I), Cp(CO)₂Mn(π-HCCCOOMe) (II), Cp(CO)₂Mn(CCCPh₂) (III), and Fe₂(CO)₉ in hexane gives rise to the complexes Cp(CO)₂Mn(μ²-CCHCOOMe)Fe(CO)₄ (IVa,b) and Cp(CO)₂Mn(μ²-CCCPh₂)Fe(CO)₄ (VIII). The structure of IVb was determined by X-ray analysis. This compound is a binuclear complex with the Fe(CO)₄ and Cp(CO)₂Mn fragments linked by a FeMn bond and a carbomethoxyvinylidenic ligand. Compound IVa is a geometrical isomer of IVb.     

Synthese und reaktivität von silicium-übergangsmetall-komplexen: XVIII. Trihydrosilylkomplexe des eisens: Darstellung und metallierung mit dicobaltoctacarbonyl

The reaction of the silyl complex Cp(CO)₂FeSiH₃ (1) with various donors under photochemical conditions leads to the formation of Cp(CO)(L)FeSiH₃ (2a-2c) and Cp(L)₂FeSiH₃ (3a, 3b) (L = MeNC, t-BuNC, Me₃P) via stepwise CO-substitution. 2a,2b are transformed by Co₂(CO)₈ to the complexes μ₂-[Cp(CO)-(RNC)FeSiH] [μ²-(CO)] Co₂(CO)₆ (3a,3b), the first complexes with a hydrogen substituted ferrio-silanediyl unit bridging two cobalt atoms.     

Synthese und Reaktivität von Silicium-übergangsmetall-Komplexen: XXI. Ferrio-azidosilane and Ferriosilyl-iminophosphorane

Reaction of the ferriochlorosilanes R₅C₅(CO)₂FeSiR′_3-nCl_n (1a–1f) with sodium azide in tetrahydrofuran yields the ferrio- (mono-, bis-, and tris-azido)silanes R₅C₅(CO)₂FeSiR′_3-n(N₃)_n (R = H, Me; R′ = Me, H; n = 1–3) (2a–2f). CCl₄ converts Cp(CO)₂FeSiMe(H)N₃ (2a) into the ferrioazido(chloro)silane Cp(CO)₂-FeSiMe(Cl)N₃ (3). Treatment of 2d, 2f with Me₃P results in the formation of the ferriosilyl-iminophosphoranes Cp(CO)₂FeSi(N₃)(R)NPMe₃ (R = Me, N₃), (4a, 4b) by N₂ elimination.     

Reaction of Tungsten–Phosphinidene and –Arsinidene Complexes with Carbodiimides and Alkyl Azides: A Straightforward Way to Four‐Membered Heterocycles

The reaction of the phosphinidene and arsinidene complexes [Cp*E{W(CO)₅}₂] (E=P ( 1 a ), As ( 1 b ); Cp*=C₅Me₅) with carbodiimides leads to the new four‐membered heterocycles of the type [Cp*C(NR)₂E{W(CO)₅}₂] (E=P: R=iPr ( 2 a ), Cy ( 3 a ); E=As: R=iPr ( 2 b ), Cy ( 3 b )). The reaction of phosphinidene complex 1 a with alkyl azides yields the triazaphosphete derivatives [Cp*P{W(CO)₅}N(R)NN{W(CO)₅}] (R=Hex, Cy) ( 4 ). These unprecedented N₃P four‐membered triazaphosphete complexes can be regarded as stabilized intermediates of the Staudinger reaction, which have not been previously isolated. All of the isolated products were characterized by NMR, IR spectroscopy, mass spectrometry, and by single‐crystal X‐ray diffraction analysis.     

Untersuchungen zur Sb–Sb‐Bindungsknüpfung in der Koordinationssphäre von Übergangsmetallen

Investigations of Sb–Sb Bond Formation Reactions in the Coordination Sphere of Transition Metals The reaction of SbCl₃ with various transition metal metalates of the type K[ML_n] [ML_n = Ni(CO)Cp*, Fe(CO)Cp′, Co(CO)₄; Cp* = η⁵‐C₅Me₅, Cp′ = η⁵‐C₅H₄Me] in the presence of [Cr(CO)₅thf] have been studied. With K[Ni(CO)Cp*] and K[Fe(CO)₂Cp′] the trigonal‐pyramidal complexes [(μ₃‐Sb){Ni(CO)Cp*}₃] ( 1 ) and [(μ₃‐Sb){Fe · (CO)₂Cp′}₃] ( 2 ), respectively, are obtained. The reaction with K[Co(CO)₄] leads to the tetrahedral cluster [Co₃(CO)₉(μ₃‐Sb{Cr(CO)₅})] ( 3 ) and the butterfly cluster [Co₂(CO)₆(μ‐SbCl)(μ‐SbCl{Cr(CO)₅})] ( 4 ). All products are characterised by X‐ray crystal structure determination. In contrast to the corresponding [(CO)₅CrPCl₃] system forming P–P bonds, starting from SbCl₃/[Cr(CO)₅thf] does not cause a Sb–Sb bond formation.     

Phosphenium-übergangsmetallkomplexe: XX. Stabilisierung von mesitylphosphiniden durch ein Cp(CO)2W- und ein Cp(CO)2 Fe-Fragment

The reaction of the secondary metallo-phosphanes Cp(CO)₂(L)W-PH(Mes) (L  CO, PMe₃) (1a,b) with the iron complex [Cp(CO)₃Fe]BF₄ (2) or Cp(CO)2Fe-I (3), respectively, affords the ferrio(wolframio)phosphonium salts [Cp(CO)₂(L)W-P(Mes)-Fe(CO)₂Cp]X (X  I (4a), BF₄ (4b). Deprotonation of 4a, b with DBU results, in both cases, in the selective formation of a WP bond owing to additional CO- or Me₃P-elimination to give the phosphinidene complex Cp(CO)₂WP(Mes)-Fe(CO)₂Cp (6).     

Electrochemical reduction of transition metal-substituted silicon,germanium and tin derivatives: I. Cobalt or cobalt and iron complexes

The complexes Ph₃ECo(CO)₃L (E = Si, Ge; L = CO, PPh₃ P(OPh)₃) have been studied by electrochemistry. The reduction potential of these derivatives is less affected by the nature of the ligand L than in the case of [CO(CO)₃L]₂. The electrochemical reduction of the tin complexes [Co(CO)₄]_n[Fe(CO)₂Cp]_3?nSnCl (n = 1–3) showed that the formation of the radical anion occurred with tin-cobalt rather than tin-chloride bond rupture. Electrolysis of these tin derivatives did not give any distannane containing transition metal groups. However it can be noted that the Fe(CO)₂Cp group stabilized these tin complexes.     

Neue metallorganisch substituierte Indium–Stickstoff-Verbindungen. Synthese und Kristallstrukturen von [{Cp(CO)3Mo}2InN(SiMe3)2] und [{Cp(CO)3Mo}In{N(SiMe3)2}2]

New Organometallic Indium Nitrogen Compounds. Synthesis and Crystal Structures of [{Cp(CO)₃Mo}₂InN(SiMe₃)₂] and [{Cp(CO)₃Mo}In{N(SiMe₃)₂}₂] The reaction of [{Cp(CO)₃Mo}₂InCl] with LiN · (SiMe₃)₂ leads to the formation of [{Cp(CO)₃Mo}₂InN · (SiMe₃)₂] ( 1 ). 1 is monomeric and it contains an indium atom which is coordinated in a trigonal planar manner by two {Cp(CO)₃Mo} fragments and a N(SiMe₃)₂ group. The corresponding bis-amide [{Cp(CO)₃Mo}In{N(SiMe₃)₂}₂] ( 2 ) is prepared by the reaction of [{Cp(CO)₃Mo}InCl₂] with two equivalents of LiN(SiMe₃)₂. In analogy to 1, 2 is monomeric and it contains an indium atom in a trigonal planar coordination.     

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.     

Reaction of Pentelidene Complexes with Diazoalkanes: Stabilization of Parent 2,3‐Dipnictabutadienes

The reaction of the phosphinidene complex [Cp*P{W(CO)₅}₂] ( 1 a ) with diphenyldiazomethane leads to [{W(CO)₅}Cp*P=NN{W(CO)₅}=CPh₂] ( 2 ). Compound 2 is a rare example of a phosphadiazadiene ligand (R‐P=N?N=CR′R′′) complex. At temperatures above 0 °C, 2 decomposes into the complex [{W(CO)₅}PCp*{N(H)N=CPh₂)₂] ( 3 ), among other species. The reaction of the pentelidene complexes [Cp*E{W(CO)₅}₂] (E=P, As) with diazomethane (CH₂NN) proceeds differently. For the arsinidene complex ( 1 b ), only the arsaalkene complex 4 b [{W(CO)₅}₂{η^1:2‐(Cp*)As=CH₂}] is formed. The reaction with the phosphinidene complex ( 1 a ) results in three products, the two phosphaalkene complexes [{W(CO)₅}₂{η^1:2‐(R)P=CH₂}] ( 4 a : R=Cp*, 5 : R=H) and the triazaphosphole derivative [{W(CO)₅}P(Cp*)‐CH₂‐N{W(CO)₅}=N‐N(N=CH₂)] ( 6 a ). The phosphaalkene complex ( 4 a ) and the arsaalkene complex ( 4 b ) are not stable at room temperature and decompose to the complexes [{W(CO)₅}₄(CH₂=E?E=CH₂)] ( 7 a : E=P, 7 b : E=As), which are the first examples of complexes with parent 2,3‐diphospha‐1,3‐butadiene and 2,3‐diarsa‐1,3‐butadiene ligands.     

Regioselective silylphosphination of methyl vinyl ketone with complexes containing cyclic and linear iron-silicon-phosphorus reacting sites

Treatment of Cp*(CO)Fe{kappa2(Si,P)-SiMe2PPh2} with methyl vinyl ketone gave a 1,2-addition product, Cp*(CO)Fe{kappa2(Si,P)-SiMe2OCMe(CH=CH2)PPh2}. A linear-type Cp*(CO)2FeSiMe2PPh2 also reacted with the ketone to yield a 1,4-addition product, Cp*(CO)2Fe{kappa1(Si)-SiMe2OC(Me=CHCH2PPh2}, which was further converted to a seven-membered metallacycle, Cp*(CO)Fe{kappa2(Si,P)-SiMe2OC(Me)=CHCH2PPh2}, upon photolysis.     

Synthesis and characterization of group 6-9 metal-rich homo- and hetero-metallaboranes

To isolate the metal-rich metallaboranes of group 6-9, we have performed the reaction of various reaction intermediates, generally synthesized from the low-temperature reactions of [Cp1WCl₄] (Cp1 ​= ​η⁵-C₅Me₅), [(Cp1RhCl₂)₂], or [(Cp1RuCl₂)₂] and [LiBH₄ THF] with different transition metal carbonyl compounds. For example, the thermolytic reaction of [Fe₂(CO)₉] with an in situ generated intermediate, produced from the reaction of [Cp1WCl₄] and [LiBH₄THF] afforded a trigonal bipyramidal cluster, [(μ₃-BH)₂H₂{Cp1W(CO)₂}{Cp1W(CO)}{Fe(CO)₃}], 1 which contains a triply-bridging bis-{hydrido(borylene)} ligand. Similarly, the reaction of [Co₂(CO)₈] with nido-[(RhCp1)₂(B₃H₇)] I at room temperature, yielded an octahedral cluster, [(Cp1Rh)₂B₂H₂Co₂(CO)₅(μ₃-CO)], 2. In this reaction, nido-I having (n+2) skeletal electron pairs (SEP) goes on for the formation of a closo-rhodaborane with (n+1) SEP. In addition, we have isolated a trinuclear bis(μ₃-oxo) metalla cluster [(Cp1Ru)₃(μ₃-OBF₃)₂(μ-H)], 3. Compound 3 can be considered as cluster having trigonal bipyramidal geometry with exo-BF₃ fragment. All these clusters were characterized by IR, mass spectrometry, NMR, and single-crystal X-ray crystallographic analysis.