Ein Beitrag zur Reaktivität von (η5-C5Me5)(CO)2FeP(SiMe3)2 gegenüber P-Chlormethylenphosphanen

On the Reactivity of (η⁵-C₅Me₅)(CO)₂FeP(SiMe₃)₂ Toward P-Chloromethylene phosphanes The reaction of (η⁵-C₅Me₅)(CO)₂FeP(SiMe₃)₂ ( 2 ) with three equivalents of Cl? P?C(SiMe₃)₂ ( 3a ) afforded the 3-methanediyl-1,3,5,6-tetraphosphabicyclo[3.1.0]hex-2-ene (η⁵-C₅Me₅)(CO)₂Fe? ( 6a ). In contrast, 2 reacts with two equivalents of Cl? P?C(Ph)SiMe₃ ( 3b ) to give the thermolabile (η⁵-C₅Me₅) · (CO)₂Fe? P[P?C(Ph)SiMe₃]₂ ( 4b ) which decomposed during the reaction with further 3b. 4 b was also obtained from (η⁵-C₅Me₅)(CO)₂Fe? P(SiMe₃)? P?C(SiMe₃)₂ ( 1a ) and two equivalents of 3b .     

Übergangsmetall-substituierte Acylphosphane und Phosphaalkene. 22 [1] Insertionen von Hexafluoraceton in die PX-Bindung von Metallophosphanen des Typs (η5-C5Me5)(CO)2M?PX2 (M = Fe,Ru; X = Me3Si,Cl). Strukturbestimmung von (η5-C5Me5)(CO)2Fe?P(SiMe3)C(CF3)2(OSiMe3)

Transition Metal-substituted Acylphosphanes and Phosphaalkenes. 22. Insertions of Hexafluoroacetone into the PX-Bond of Metallophosphanes (η⁵-C₅Me₅)(CO)₂M? PX₂ (M = Fe, Ru; X = Me₃Si, Cl). Structure Determination of (η⁵-C₅Me₅)(CO)₂Fe? P(SiMe₃)C(CF₃)₂(OSiMe₃) Reaction of the metallophosphanes (η⁵-C₅Me₅)(CO)₂M? P(SiMe₃)₂ ( 1a : M = Fe; 1b : M = Ru) with hexafluoroacetone (HFA) afforded the complexes (η⁵-C₅Me₅)(CO)₂M? P(SiMe₃)C(CF₃)₂(OSiMe₃) ( 2a, b ). The attempted synthesis of a metallophosphaalkene from 2a by thermal elimination of hexamethyldisiloxane failed. The acid catalyzed hydrolysis of 2a afforded compound (η⁵-C₅Me₅) · (CO)₂Fe? P(H)C(CF₃)₂(OSiMe₃) ( 3 ). Hexafluoracetone and (η⁵-C₅Me₅)(CO)₂Fe? PCl₂ ( 4 ) under-went reaction to give the metallochlorophosphan (η⁵-C₅Me₅) · (CO)₂Fe? P(Cl)? O? C(CF₃)₂Cl ( 5 ). Constitutions and configurations of the compounds ( 2–5 ) were established by elemental analyses and spectroscopic data (IR, ¹H-, ¹³C, ¹⁹F-, ²⁹Si-, ³¹P-NMR, MS). The molecular structure of 2a was determined by x-ray diffraction analysis.     

Reactions of tungsten and molybdenum propargyl complexes with Co2(CO)8, Co4(CO)12, and Cp2Mo2(CO)4. A crossover study of formation of (CO)3 Cp(CO)2

The nature of the protonation reaction of (

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o(CO)₃ (M = Mo, W; R = Me, Ph, p-MeC₆H₄) (2) (obtained from (CO)₃CpMCH₂CCR (1) and Co₂(CO)₈) to give (CO)₃ Cp(CO)₂ (3) was further investigated by a crossover experiment. Thus, reaction of an equimolar mixture of 2b (M = W, Cp = η⁵-C₅H₅, R = Ph) and 2e (M = W, Cp = η⁵-C₅H₄Me; R = p-MeC₆H₄) with CF₃COOH affords only 3b (same M, Cp, and R as 2b) and 3e (same M, Cp, and R as 2e) to show an intramolecular nature of this transformation. Reaction of (CO)₃CpWCH₂CCPh (1b) with Co₄(CO)₁₂ was also examined and found to yield 2b exclusively. Treatment of 1 with Cp₂Mo₂(CO)₄ at 0–5°C provides thermally sensitive compounds, possibly (CO)₂Cp

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oCp(CO)₂ (5), which decompose at room temperature to give Cp₂Mo₂(CO)₆ as the only isolated product.     

Synthesis and structures of crystalline lithium 1-azaallyls and a 1,3-diazaallyl derived from Li{CH(SiMe3)(SiMe3−n(OMe)n)} (n=1 or 2) and Li{CH(SiMe2OMe)2} and RCN (R=Bu, Ph, 2,5-Me2C6H3, or Ad)

Crystalline [Li{N(SiMe₂OMe)C(^tBu)C(H)(SiMe₃)}]₂ (5), [Li{N(SiMe₂OMe)C(Ph)C(H)(SiMe₃)}]₂ (6), [C(C₆H₃Me₂-2,5)C(H)(SiMe₃)}(TMEDA)](7), [Li{N(SiMe(OMe)₂)C(^tBu)C(H)(SiMe₃)}(THF)]₂ (8), Li{N(SiMe(OMe)₂)C(Ph)C(H)(SiMe₃)}(TMEDA) (9) and [Li{N(SiMe₂OMe)C(^tBu)C(H)(SiMe₂OMe)}]₂ (10) were readily obtained at ambient temperature from (i) [Li{CH(SiMe₃)(SiMe₂OMe)}]₈ (1) and an equivalent portion of RCN (R=^tBu (5), Ph (6) or 2,5-Me₂C₆H₃ (7)); (ii) [Li{CH(SiMe₃)(SiMe(OMe)₂)}]_∞ (2) and an equivalent portion of ^tBuCN (8) or PhCN (9); and (iii) [Li{CH(SiMe₂OMe)₂}]_∞ (3) and one equivalent of ^tBuCN (10). Reactions (i) and (ii) were regiospecific with SiMe_3−n(OMe)_n>SiMe₃ in 1,3-migration from C (in 1 or 2)→N. The 1-azaallyl ligand was bound to the lithium atom as a terminally bound κ¹-enamide (8 and 10), a bridging η³-1-azaallyl (6), or a bridging κ¹-enamide (5). The stereochemistry about the CC bond was Z for 5, 8 and 10 and E for 7. X-ray data are provided for 5, 6, 7, 8 and 10 and multinuclear NMR spectra data in C₆D₆ or C₆D₅CD₃ for each of 5-10.     

Über den Phosphandiyl‐Transfer von invers‐polarisierten Phosphaalkenen R1P=C(NMe2)2 (R1 = tBu,Cy, Ph,H) auf Phospheniumkomplexe [(η5‐C5H5)(CO)2M=P(R2)R3] (R2 = R3 = Ph; R2 = tBu,R3 = H; R2 = Ph,R3 = N(SiMe3)2)

Phosphanediyl Transfer from Inversely Polarized Phosphaalkenes R¹P=C(NMe₂)₂ (R¹ = tBu, Cy, Ph, H) onto Phosphenium Complexes [(η⁵‐C₅H₅)(CO)₂M=P(R²)R³] (R² = R³ = Ph; R² = tBu, R³ = H; R² = Ph, R³ = N(SiMe₃)₂) Reaction of the freshly prepared phosphenium tungsten complex [(η⁵‐C₅H₅)(CO)₂W=PPh₂] ( 3 ) with the inversely polarized phosphaalkenes RP=C(NMe₂)₂ ( 1 ) ( a : R = tBu; b : Cy; c : Ph) led to the η²‐diphosphanyl complexes ( 9a‐c ) which were isolated by column chromatography as yellow crystals in 24‐30 % yield. Similarly, phosphenium complexes [(η⁵‐C₅H₅)(CO)₂M=P(H)tBu] (M = W ( 6 ); Mo ( 8 )) were converted into (M = W ( 11 ); Mo ( 12 )) by the formal abstraction of the phosphanediyl [PtBu] from 1a . Treatment of [(η⁵‐C₅H₅)(CO)₂W=P(Ph)N(SiMe₃)₂] ( 4 ) with HP=C(NMe₂)₂ ( 1d ) gave rise to the formation of yellow crystalline ( 10 ). The products were characterized by elemental analyses and spectra (IR, ¹H, ¹³C‐, ³¹P‐NMR, MS). The molecular structure of compound 10 was elucidated by an X‐ray diffraction analysis.     

Reactions of the cycloheptatrienyl complexes [MX(CO)2(η-C7H7)] (M=Mo, X=Br; M=W, X=I) with CNBu: X-ray crystal structure of [WI(CO)2(CNBu)2(η-C7H7)]

Reaction of [MX(CO)₂(η⁷-C₇H₇)] (M=Mo, X=Br; M=W, X=I) with two equivalents of CNBu^t in toluene affords the trihapto-bonded cycloheptatrienyl complexes [MX(CO)₂(CNBu^t)₂(η³-C₇H₇)] (1, M=Mo, X=Br; 2, M=W, X=I). The X-ray crystal structure of 2 reveals a pseudo-octahedral molecular geometry with an asymmetric ligand arrangement at tungsten in which one CNBu^t is located trans to the η³-C₇H₇ ring. Treatment of 2 with tetracyanoethene results in 1,4-cycloaddition at the η³-C₇H₇ ring to give [WI(CO)₂(CNBu^t)₂{η³-C₉H₇(CN)₄}], 3. The principal reaction type of the molybdenum complex 1 is loss of carbonyl and bromide ligands to afford substituted products [MoBr(CNBu^t)₂(η⁷-C₇H₇)] 4 or [Mo(CO)(CNBu^t)₂(η⁷-C₇H₇)]Br. Reaction of [MoBr(CO)₂(η⁷-C₇H₇)] with one equivalent of CNBu^t in toluene at 60°C affords [MoBr(CO)(CNBu^t)(η⁷-C₇H₇)], 5, which is a precursor to [Mo(CO)(CNBu^t)(NCMe)(η⁷-C₇H₇)][BF₄], 6, by reaction with Ag[BF₄] in acetonitrile. In contrast with the parent dicarbonyl systems [MoX(CO)₂(η⁷-C₇H₇)], complexes of the Mo(CO)(CNBu^t)(η⁷-C₇H₇) auxiliary, 5 and 6, do not afford observable η³-C₇H₇ products by ligand addition at the molybdenum centre.     

Synthese,Struktur und Reaktivität von funktionalisierten Stibanidokomplexen des Eisens und Rutheniums [(η5-C5Me5)(CO)2MSbR1R2] (M = Fe,Ru; R1, R2 = SiMe3, C(O)tBu,C(O)Ph,C(O)-1 Ad)

Synthesis, Structure, and Reactivity of Functionalized Stibanido Complexes of Iron and Ruthenium [(η⁵-C₅Me₅)(CO)₂MSbR¹R²] (M = Fe, Ru; R¹, R² = SiMe₃, C(O) t Bu, C(O)Ph, C(O)-1 Ad) The reaction of equimolar amounts of [(η⁵-C₅Me₅)(CO)₂RuSb(SiMe₃)₂] ( 1 b ) and the carboxylic chlorides RC(O)Cl (R = tBu, Ph, 1-adamantyl) afforded the acyl(trimethylsilyl)stibanido complexes [(η⁵-C₅Me₅)(CO)₂RuSb · {C(O)R}(SiMe₃)] 2 b (R = tBu), 4 b (R = Ph), and 6 b (R = 1-Ad). The treatment of 1 b with two molar equivalents of pivaloyl chloride and benzoyl chloride led to the diacylstibanido complexes [(η⁵-C₅Me₅)(CO)₂RuSb{C(O)R}₂] ( 3 b , 5 b ). Analogously, the iron complex [(η⁵-C₅Me₅)(CO)₂FeSb · (SiMe₃)₂] ( 1 a ) is converted into the corresponding diacylstibanido complexes 3 a (R = tBu), 5 a (R = Ph) and 7 a (R = 1-Ad) by an excess of acid chloride. The treatment of 1 a with equimolar amounts of RC(O)Cl gave inseparable mixtures of starting material and the monoacyl- and diacyl stibanido complexes. Oxalyl chloride reacted quantitatively with two equivalents of 1 a to give complex [{(η⁵-C₅Me₅) · (CO)₂FeSb(SiMe₃)C(O)}₂] ( 8 ). The molecular structures of 1 a , 2 b and 5 b were elucidated by single crystal X-ray analyses.     

Synthesis and crystal structures of organometallic compounds containing the ligands C(SiMe3)2(SiMe2H) and C(SiMe2Ph)2(SiMe2H)

Metallation of (HMe₂Si)(Me₃Si)₂CH (1) by LiMe gave the organolithium compound Li(THF)₂C(SiMe₃)₂(SiMe₂H) (2a), which exists in toluene solution as a mixture of covalent species and ion pairs [Li(THF)₄][Li{C(SiMe₃)₂(SiMe₂H)}₂] (2b). Treatment of a mixture of 1 and LiMe with KOBu^t gave KC(SiMe₃)₂(SiMe₂H) (3). This reacted with AlMe₂Cl in hexane/THF to give Al(THF)Me₂{C(SiMe₃)₂(Si Me₂H)} (4). Treatment of (HMe₂Si)(PhMe₂Si)₂CH (5) with LiMe in Et₂O/THF gave the THF adduct [Li(THF)₂C(SiMe₂Ph)₂(SiMe₂H)] (6); in the presence of KOBu^t the solvent-free [K][C(SiMe₂Ph)₂(SiMe₂H)] (7) was obtained. Crystal structure determinations showed that 6 crystallizes in a molecular lattice and 7 in an ionic lattice in which the coordination sphere of the potassium comprises phenyl groups and hydrogen atoms attached to silicon, as well as the central carbon of the bulky carbanion. Compound 7 reacted with an excess of AlMe₂Cl to give [AlClMe{C(SiMe₂Ph)₂(SiMe₂H)}]₂ (8) and AlMe₃. A small amount of the methoxo derivative [Al(OMe)Me{C(SiMe₂Ph)₂(SiMe₂H)}]₂ (9) was obtained as a byproduct, presumably after the accidental admission of traces of air. X-ray structural determinations showed that 8 forms halogen-bridged dimers, with the bulky ligands in the anti-configuration, and 9 forms methoxo-bridged species in which the bulky ligands are syn.     

Novel sandwich complexes of zirconium [C9H5(SiMe3)2](C5Me4R)ZrCl2 (R = CH3, CH2CH2NMe2): Synthesis and reduction behavior

Novel half-sandwich [C₉H₅(SiMe₃)₂]ZrCl₃ (3) and sandwich [C₉H₅(SiMe₃)₂](C₅Me₄R)ZrCl₂ (R = CH₃ (1), CH₂CH₂NMe₂ (2)) complexes were prepared and characterized. The reduction of 2 by Mg in THF lead to (η⁵-C₉H₅(SiMe₃)₂)[η⁵:η²(C,N)-C₅Me₄CH₂CH₂N(Me)CH₂]ZrH (7). The structure of 7 was proved by NMR spectroscopy data. Hydrolysis of 2 resulted in the binuclear complex ([C₅Me₄CH₂CH₂NMe₂]ZrCl₂)₂O (6). The crystal structures of 1 and 6 were established by X-ray diffraction analysis.     

Zur Reaktivität der Ferriophosphaalkene [(η5‐C5Me5)(CO)2FeP=C(NR)R2] (NR = NMe2, NC5H10, R2 = Ph,tBu) gegenüber Protonsäuren,Alkylierungsmitteln und [{(Z)‐Cycloocten}Cr(CO)5]

Transition Metal‐substituted Phosphaalkenes. 42 Reactivity of the Ferriophosphaalkenes [(η⁵‐C₅Me₅)(CO)₂FeP=C(NR )R²] (NR = NMe₂, NC₅H₁₀, R² = Ph, t Bu) towards Protic Acids, Alkylation Reagents, and [{( Z )‐Cyclooctene}Cr(CO)₅] The reaction of equimolar amounts of [(η⁵‐C₅Me₅)(CO)₂FeP=C(NR )R²] ( 2 a : NR = NMe₂, R² = Ph; 2 b : NMe₂. tBu; 2 c : NC₅H₁₀, Ph) and etherial HBF₄ gave rise to the formation of [(η⁵‐C₅Me₅)(CO)₂FeP(H)C(NR )R²] (BF₄) ( 3 a – c ) which were isolated as light red powders. Compounds 2 a – c were converted into [(η⁵‐C₅Me₅)(CO)₂FeP(Me)C(NR )R²] (SO₃CF₃) ( 4 a – c ) by treatment with methyl trifluoromethane sulfonate. In addition 2 a and Me₃SiCH₂OSO₂CF₃ afforded light red [(η⁵‐C₅Me₅)(CO)₂FeP(CH₂SiMe₃)C(NMe₂)Ph](SO₃CF₃) ( 5 ). The black complex [(η⁵‐C₅Me₅)(CO)₂FeP{Cr(CO)₅}C(NMe₂)Ph] ( 6 ) resulted from the combination of 2 a with [{(Z)‐cyclooctene}Cr(CO)₅]. The novel products were characterized by elemental analyses and spectra (IR, ¹H‐, ¹³C‐ und ³¹P‐NMR).     

Substituted cyclopentadienyl ligands—10. Intramolecular steric interactions in [(η-C5H3(SiMe3)2)Mo(CO)2(L)I]

Reaction of C₅H₄(SiMe₃)₂ with Mo(CO)₆ yielded [(η⁵-C₅H₃(SiMe₃)₂)Mo(CO)₃]₂, which on addition of iodine gave [(η⁵-C₅H₃(SiMe₃)₂Mo(CO)₃I]. Carbonyl displacement by a range of ligands: [L  P(OMe)₃, P(OPrⁱ)₃,P(O-o-tol)₃, PMe₃, PMe₂Ph, PMePh₂, PPh₃, P(m-tol)₃] gave the new complexes [(η⁵-C₅H₃(SiMe₃)₂ MO(CO)₂(L)I]. For all the trans isomer was the dominant, if not exclusive, isomer formed in the reaction. An NOE spectral analysis of [(η⁵-C₅H₃(SiMe₃)₂)Mo(CO)₂(L)I] L  PMe₂Ph, P(OMe)₃] revealed that the L group resided on the sterically uncongested side of the cyclopentadienyl ligand and that the ligand did not access the congested side of the molecule. Quantification of this phenomenon [L  P(OMe)₃] was achieved by means of the vertex angle of overlap methodology. This methodology revealed a steric preference with the trans isomer (less congestion of CO than I with an SiMe₃ group) being the more stable isomer for L  P(OMe)₃.     

The reactions of [Co(η-C5H5)(CO)(L)] (L = R3P or RNC) with carbon disuphide and organoisothiocyanates

The reactions of [Co(η-C₅H₅)(CO)(PR₃)] or [Co(η-C₅GH₅)(CO)₂]/R₃P mixtures (R = alkyl or aryl) with CS₂ in refluxing CS₂ or CS₂/toluene gives rise to [Co(η-C₅H₅)(PR₃)(CS)], [Co(η-C₅H₅)(PR₃)(CS₂)], [Co(η-C₅H₅)(PR₃)(CS₃)], and [Co₃(η-C₅H₅)₃ (CS)(S)] in reasonable yields. The corresponding reactions using PhNCS give [Co(η-C₅H₅)(PPh₃)(PhNCS)] and a polymeric species which appears to be [Co₄(η-C₅H₅)₄ (PhNCS)]. Similar products are obtained with [Co(η-C₅H₅)(CO)(CNR)] or [Co(η0C₅H₅)(CO)₂]/RNC mixtures.     

(η5-C5R5)2Fe2(CO)2(μ-CO)(μ-CH2) (R = H,CH3): A convenient one-pot synthesis using chloromethyl pivalate

The compounds (η⁵-C₅R₅)₂Fe₂(CO)₂(μ-CO)(μ-CH₂) (R = H, CH₃) have been prepared through the reaction of chloromethyl pivalate with the appropriate metal anions, η⁵-C₅H₅Fe(CO)₂K and η⁵-C₅Me₅Fe(CO)₂K.     

Synthesis and structures of the 2-(dimethylsila)pyrimidine derivatives (Ar = Ph, C6H4Bu-4; X = H, SiMe3, Li(hmpa)2, K(thf)3; n = 1, 2)

Five crystalline 2-(dimethylsila)pyrimidine derivatives (Z) have been prepared in excellent 1–4 or satisfactory 5 yield and characterised. The source of each was ultimately Li[CH(SiMe₂R)(SiMe₂OMe)] [R = Me (B) or OMe (I)]. Compound 1 (Z with Ar = Ph, X = SiMe₃, n = 1) was obtained from Z [with Ar = Ph, X = Li(OEt₂), n = 4; previously isolated from B [P.B. Hitchcock, M.F. Lappert, X.-H. Wei, J. Organomet. Chem. 689 (2004) 1342]] and Me₃SiCl. The potassium salt 2 [Z with Ar = C₆H₄Bu^t-4; X = K(thf)₃, n = 2] was made from K[CH(SiMe₃)(SiMe₂OMe)] (C) (via B) and 4-Bu^tC₆H₄CN. Treatment of 2 with 1,2-dibromoethane afforded 3 (Z with Ar = 4-Bu^tC₆H₄; X = H, n = 1); which when reacted with successively n-butyllithium and Me₃SiCl produced 4 (Z with Ar = 4-Bu^tC₆H₄, X = SiMe₃, n = 1). Compound 5 [Z with Ar = 4-Bu^tC₆H₄, X = Li(hmpa)₂, n = 1] resulted from I with 4-Bu^tC₆H₄CN and then OP(NMe₂)₃ (≡ hmpa). Plausible reaction pathways from the appropriate alkali metal alkyl C or I to 2 or 5, respectively, are suggested; these involve regiospecific 1,3-migrations of SiMe₂OMe from C → N and electrocyclic loss of Me₃SiOMe or SiMe₂(OMe)₂, respectively. The X-ray structures of crystalline 1, 2 and 5 are presented.     

Cyclopentadienyl-ruthenium and -osmium chemistry : XXXIX. Syntheses of novel alkynyl-ruthenium complexes. X-Ray structures of two forms of {Ru(PPh3)2(η-C5H5)}2(μ-C4) and of Ru{CCC(O)Me}(PPh3)2(η-C5H5)

Reactions between [Ru(thf)(PPh₃)₂(η-C₅H₅)]⁺ and lithium acetylides have given further examples of substituted ethynylruthenium complexes that are useful precursors of allenylidene and cumulenylidene derivatives. From Li₂C₄, mono- and bi-nuclear ruthenium complexes were obtained: single-crystal X-ray studies have characterised two rotamers of {Ru(PPh₃)₂(η-C₅H₅)}₂(μ-C₄), which differ in the relative cis and trans orientations of the RuL_n groups. Protonation of Ru(CCCCH)(PPh₃)₂(η-C₅H₅) afforded the butatrienylidene cation [Ru(C=C=C=CH₂)(PPh₃)₂(η-C₅H₅)]⁺, which reacted readily with atmospheric moisture to give the acetylethynyl complex Ru{CCC(O)Me}(PPh₃)₂(η-C₅H₅), also fully characterised by an X-ray structural study.     

Synthesis and reactivity of new heterodinuclear iron/rhenium Cx complexes of the formula (η-C5Me5)Re(NO)(PPh3)(CC)n(η-dppe)Fe(η-C5Me5) (n = 3, 4): Redox properties and a dicobalt hexacarbonyl adduct

We report in this communication the synthesis and characterization of two Fe/Re heterodinuclear complexes 3_n of formula (η⁵-C₅Me₅)Re(NO)(PPh₃)(CC)_n(η²-dppe)Fe(η⁵-C₅Me₅) (n = 3, 4) as well as the hexacarbonyl dicobalt adduct (4) of the hexatriynediyl complex 3₃. We show by cyclic voltammetry that the “electronic communication” between the organometallic endgroups and thereby the thermodynamic stability of the corresponding mixed-valent (MV) parent 3_n⁺ is strongly influenced by bridge extension or by complexation of the [Co₂(CO)₆] fragment. In the case of the hexatriynediyl complex, the MV complex 3₃⁺ or 4 can be isolated by performing the chemical oxidation of 3₃ at low temperature. Spectroscopic studies of this compound and of other stable oxidized redox congeners should now help us to unravel how bridge extension modifies the electronic communication between the different redox-active endgroups in this family of unsymmetrically-substituted polyynediyl compounds.     

Synthese und Struktur von η1‐Phosphaallyl‐, η1‐Arsaallylund η1‐Stibaallyleisen‐Komplexen [(η5‐C5Me5)(CO)2Fe–E(SiMe3)C(OSiMe3)=CPh2] (E = P,As, Sb)

Syntheses and Structures of η¹‐Phosphaallyl, η¹‐Arsaallyl, and η¹‐Stibaallyl Iron Complexes [(η⁵‐C₅Me₅)(CO)₂Fe–E(SiMe₃)C(OSiMe₃)=CPh₂] (E = P, As, Sb) The reaction of equimolar amounts of [(η⁵‐C₅Me₅)(CO)₂Fe–E(SiMe₃)₂] ( 1 a : E = P; 1 b : As; 1 c : Sb) and diphenylketene afforded the η¹‐phosphaallyl‐, η¹‐arsaallyl‐, and η¹‐stibaallyl complexes [(η⁵‐C₅Me₅)(CO)₂Fe–E(SiMe₃)C(OSiMe₃)=CPh₂] ( 2 a : E = P; 2 b : As; 2 c : Sb). The molecular structures of 2 b and 2 c were elucidated by single crystal X‐ray analyses.     

Heterometallische Clusterkomplexe der Typen Re2(μ-PR2)(CO)8(HgY) und ReMo(μ-PR2)(η5-C5H5)(CO)6(HgY) (R = Ph,Cy; Y = Cl,W(η5-C5H5)(CO)3)

Heterometallic Cluster Complexes of the Types Re₂(μ-PR₂)(CO)₈(HgY) and ReMo(μ-PR₂)(η⁵-C₅H₅)(CO)₆(HgY) (R = Ph, Cy; Y = Cl, W(η⁵-C₅H₅)(CO)₃) Dinuclear complexes Re₂(μ-H)(μ-PR₂)(CO)₈ and ReMo(μ-H)(μ-PR₂)(η⁵-C₅H₅)(CO)₆ (R = phenyl, cyclohexyl) were deprotonated and reacted as anions with HgCl₂ to compounds of the both types Re₂(μ-PR₂)(CO)₈HgCl) and ReMo(μ-PR₂)(η⁵-C₅H₅)(CO)₆(HgCl). The heterometallic three-membered cluster complexes correspond to an isolobal exchange of a proton against a cationic HgCl⁺ group. For one of the products ReMo(μ-PCy₂)(η⁵-C₅H₅)(CO)₆(HgCl) has been shown its conversion with NaW(η⁵-C₅H₅)(CO)₃ to ReMo(μ-PCy₂)(η⁵-C₅H₅)(HgW(η⁵-C₅H₅)(CO)₃) under substitution of the chloro ligand, par example. The newly prepared compounds were characterized by means of IR, UV/VIS and ³¹P NMR data. A complete determination of the molecular structure by single crystal analyses was done in the case of Re₂(μ-PCy₂)(CO)₈(HgCl) and of ReMo(μ-PCy₂)(η⁵-C₅H₅)(CO)₆(HgCl) which both are dimer because of the presence of an asymmetric dichloro bridge, and of ReMo(μ-PCy₂)(η⁵-C₅H₅)(CO)₆(HgW(η⁵-C₅H₅)(CO)₃). The structural study illustrates through comparison the influence of various metal types on an interaction between centric and edge-bridged frontier orbitals in three-membered metal rings.     

Preparation and reactivity of the new cyclopentadienyl-bridged complex (Me2SiCH2CH2SiMe2)(C5H4Fe(CO)2)2

A new metal-metal bonded binuclear iron system [Me₂SiCH₂CH₂SiMe₂][η⁵-C₅H₄Fe(CO)₂]₂ (2) has been prepared by treating two equivalents of NaCp with one equivalent of ClSi(Me)₂CH₂CH₂SiClMe₂ obtaining the intermediate (C₅H₅)Si(Me)₂CH₂CH₂Si(Me)₂(C₅H₅) which then is directly allowed to react with Fe(CO)₅ given 2 in 30% yield. From this cyclopentadienyldisilyl linked system three new binuclear irom complexes are formed. Treatment of 2 with Na/Hg in THF produced the dianion [Me₂SiCH₂CH₂SiMe₂][η⁵-C₅H₄Fe(CO)₂^?]₂ which is quenched with CH₃I giving [Me₂SiCH₂CH₂SiMe₂][η⁵-C₄H₄Fe(CO)₂CH₃]₂ (4) in 76% yield. Complex 2 is oxidized with 1.2 equivalent of I₂ to give [Me₂SiCH₂CH₂SiMe₂][η⁵-C₅H₄Fe(CO)₂I]₂ (5) in 85% yield. Photolysis of 5 (1 equiv.) and PPh₃ (3 equiv.) results in the formation of the bis-substituted compound [Me₂SiCH₂CH₂SiMe₂][η⁵-C₅H₄Fe(CO)(PPh₃)I]₂ (6). These four new binuclear iron complexes are characterized by ¹H, ¹³C, and ³¹P NMR and IR spectroscopy.     

Synthese,Struktur und Reaktivität des Ferrioarsaalkens [(η5‐C5Me5)(CO)2FeAs=C(Ph)NMe2]

Synthesis, Structure, and Reactivity of the Ferrioarsaalkene [(η⁵‐C₅Me₅)(CO)₂FeAs=C(Ph)NMe₂] Reaction of equimolar amounts of the carbenium iodide [Me₂N(Ph)CSMe]I and LiAs(SiMe₃)₂ · 1.5 THF afforded the thermolabile arsaalkene Me₃SiAs = C(Ph)NMe₂ ( 1 ), which in situ was converted into the black crystalline ferrioarsaalkene [(η⁵‐C₅Me₅)(CO)₂FeAs=C(Ph)NMe₂)] ( 2 ) by treatment with [(η⁵‐C₅Me₅)(CO)₂FeCl]. Compound 2 was protonated by ethereal HBF₄ to yield [(η⁵‐C₅Me₅)(CO)₂FeAs(H)C(Ph)NMe₂]BF₄ ( 3 ) and methylated by CF₃SO₃Me to give [(η⁵‐C₅Me₅)(CO)₂FeAs(Me)C(Ph)NMe₂]‐ SO₃CF₃ ( 4 ). [(η⁵‐C₅Me₅)(CO)₂FeAs[M(CO)_n]C(Ph)NMe₂] ( 5 : [M(CO)_n] = [Fe(CO)₄]; 6 : [Cr(CO)₅]) were isolated from the reaction of 2 with [Fe₂(CO)₉] or [{(Z)‐cyclooctene}Cr(CO)₅], respectively. Compounds 2 – 6 were characterized by means of elemental analyses and spectroscopy (IR, ¹H, ¹³C{¹H}‐NMR). The molecular structure of 2 was determined by X‐ray diffraction analysis.