Einführung eines terminalen Halogenoliganden in diorgano-verbrücke Dirhenium- und Molybdän-Rhenium-Komplexanionen in Gegenwart eines Amidinkations

Insertion of a Terminal Halogeno Ligand into Diorgano-bridged Dirhenium and Rhenium-Molybdenum Complex Anions in the Presence of an Amidin Cation and the Isomerization Processes The equimolar reaction of in situ generated anion Anions Re₂(μ-PCy₂)(CO)₈^? (Re? Re) in the presence of a steric expansive amidine cation DBUH⁺ with bromine and iodine in tetrahydrofuran solution gave the two isomers Re₂(PCy₂)(CO)₈X (Re? Re) and Re₂(μ-PCy₂)(μ-X)(CO)₈ (X = Br, I), of which the isomer with a terminal X ligand as major product was formed under maintenance of the Re? Re bond. The monotropic isomerization process of Re₂(μ-PCy₂)(CO)₈I runs thermically relative slowly, but more rapid in photochemical and electrochemical processes. The analogeous reaction of the heterometallic anion ReMo(η⁵-C₅H₅)(μ-PPh₂)(CO)₆^? with iodine delivers opposite to the former reaction mainly the bridged isomer ReMo(η⁵-C₅H₅)(μ-PPh₂μ-I)(CO)₆ besides ReMo(η⁵-C₅H₅)(μ-PPh₂)(CO)₆I. The obtained complexes were characterized by means of v(CO) and ³¹P NMR spectroscopic measurements. Single-crystal analyses led to the subsequent metal—metal bond lengths: Re? Re of 308.0(1) pm in Re₂(μ-PCy₂)(CO)₈Br and Re? Mo of 313.6(1) pm in ReMo(η⁵-C₅H₅)(μ-PPh₂)(CO)₆I.     

Darstellung carboxylatsubstituierter Rhenium-Gold-Metallatetrahedrane Re2(AuPPh3)2(μ-PCy2)(CO)7(η1-OC(R)O) (R = H,Me, CF3, Ph, 3,4-(OMe)2C6H3)

Synthesis of Carboxylate Substituted Rhenium Gold Metallatetrahedranes Re₂(AuPPh₃)₂(μ-PCy₂)(CO)₇(η¹-OC(R)O) (R = H, Me, CF₃, Ph, 3,4-(OMe)₂C₆H₃) The reaction of the in situ prepared salt Li[Re₂(μ-H)(μ-PCy₂)(CO)₇(ax-C(Ph)O)] ( 2 ) with 1,5 equivalents of monocarboxylic acid RCOOH (R = H ( 4 a ), Me ( 4 b ), CF₃ ( 4 c ), Ph ( 4 d ), 3,4-(OMe)₂C₆H₃ ( 4 e ) in tetrahydrofruan (THF) solution at 60 °C gives within 4 h under release of benzaldehyde (PhCHO) the η¹-carboxylate substituted dirhenium salt Li[Re₂(μ-H)(μ-PCy₂)(CO)₇(η¹-OC(R)O)] (R = H ( 4 a ), Me ( 4 b ), CF₃ ( 4 c ), Ph ( 4 d ), 3,4-(OMe)₂C₆H₃ ( 4 e )) in almost quantitative yield. The lower the pK_a value of the respective carboxylic acid the faster the reaction proceeds. It was only in the case of CF₃COOH possible to prove the formation of the hydroxycarbene complex Re₂(μ-H)(μ-PCy₂)(CO)₇(=C(Ph)OH) ( 5 ) prior to elimination of PhCHO. The new compounds 4 a–4 e were only characterized by ³¹P NMR and ν(CO) IR spectroscopy as they are only stable in solution. They are converted with two equivalents of BF₄AuPPh₃ at 0 °C in a so-called cluster expansion reaction into the heterometallic metallatetrahedrane complexes Re₂(AuPPh₃)₂(μ-PCy₂)(CO)₇(η¹-OC(R)O) (R = H ( 7 a ), Me ( 7 b ), CF₃ ( 7 c ), Ph ( 7 d ), 3,4-(OMe)₂C₆H₃ ( 7 e )) (yield 47–71% ). The expected precursor complexes of 7 a–7 e Li[Re₂(AuPPh₃)(μ-PCy₂)(CO)₇(η¹-OC(R)O] ( 8 ) were not detected by NMR and IR spectroscopy in the course of the reaction. Their existence was retrosynthetically proved by the reaction of 7 b with an excess of the chelating base TBD (1,5,7-Triazabicyclo[4.4.0]dec-5-en) forming [(TBD)_xAuPPh₃][Re₂(AuPPh₃)(μ-PCy₂)(CO)₇(η¹-OC(Me)O] ( 8 b ) in solution. The η¹-bound carboxylate ligand in 7 a–7 e can photochemically be converted into a μ-bound ligand in Re₂(AuPPh₃)₂(μ-PCy₂)(μ-OC(R)O)(CO)₆ (R = H ( 9 a ), Me ( 9 b ), CF₃ ( 9 c ), Ph ( 9 d ), 3.4-(MeO)₂C₆H₃ ( 9 e )) under release of one equivalent CO. All isolated cluster complexes were characterized and identified by the following analytical methods: elementary analysis, NMR (¹H, ³¹P) spectroscopy, ν(CO) IR spectroscopy and in the case of 7 d and 9 b by X-ray structure analysis.     

Deprotonierung von Mn2(μ-H)(μ-PR2)(CO)8 (R=Ph,Cy) zur Synthese von Heteronuklearen Mangan—Gold Clustern mit Mn2Aun-Kernen (n = 1 – 3)

Deprotonation of Mn₂(μ-H)(μ-PR₂)(CO)₈ (R = Ph Cy) for Synthesis of Heteronuclear Manganese-Gold Clusters with Mn₂Au_n Cores (n = 1–3) The dimanganese complexes Mn₂(μ-H)(μ-PR₂)(CO)₈ (R = Ph, Cy) have been deprotonated with 1,8-diazabicyclo[5.4.0]undec-7-en (DBU) in tetrahydrofuran solution at 20^°C to give the anions [Mn₂(μ-PR₂)(CO)₈]^?, which were isolated as tetraethylammonium salts. Both dimanganese complexes and the related anions were measured by cyclic voltammetry. The treatment of the aforementioned dimanganese complexes in thf solution with Lir' (R =Me, Ph) and subsequently with PPh₃AuCl gave at 20^°C three types of products: Mn₂(μ-PR₂(CO)₈(AuPPh₃),Mn₂(μ-PR₂)(μ-C(R′)O)(CO)₆-(AuPPh₃)₂ and Mn₂(μ-PR₂)(CO)₆(AuPPh₃)₃. The newly prepared substances were characterized by means of IR-, UV/VIS, ³¹P NMR data. The results of single X-ray analyses showed for the three-membered metal ring compound Mn₂(μ-PPh₂)(CO)₈(AuPPh₃) an uni-fold bridged σ(Mn? Mn) bond length of 306.7(3) pm, the metallatetrahedron complex Mn₂(μ-PPh₃)(μ-C(Ph)O(CO)₆(AuPPh₃)₂ a twofold bridged σ(Mn? Mn) bond length of 300.6(4) pm and the trigonal-bipyramidal cluster Mn₂(μ-Pph₂)(CO)₆(AuPPh₃)₃ an uni-fold bridged π(Mn? Mn) bond length of 274.7(3) pm. The Mn? Au bonds of these substances are accompanyied by semi-bridging CO ligands which are signified through short Au…C contact lengths in the range of 251 to 270 pm. In the substance with the Mn₂Au₂ metallatetrahedron core exists, additionally, such a contact with the acylic C atom of C(Ph)O bridging group of 263.4(18) pm. Such contact lengths were compared for corresponding dimanganese and dirhenium complexes.     

Übergangsmetall-substituierte Acylphosphane und Phosphaalkene. 17 [1] Synthese und Struktur der μ-Isophosphaalkin-Komplexe [(η5-C5H5)2(CO)2Fe2(μ-CO)(μ-CPC6H2R3-2,4,6)] (R = Me,iPr, tBu)

Transition Metal Substituted Acylphosphanes and Phosphaalkenes. 17. Synthesis and Structure of the μ-Isophosphaalkyne Complexes [(η⁵-C₅H₅)₂(CO)₂Fe₂(μ-CO)(μ-C?PC₆H₂R₃)] (R = Me, iPr, tBu) . Condensation of (η⁵-C₅H₅)₂(CO)₂Fe₂(μ-CO)(μ-CSMe)}⁺SO₃CF₃^? ( 6 ) with 2,4,6-R₃C₆H₂PH(SiMe₃) ( 7 ) ( a : R = Me, b : R = iPr, c : R = tBu) affords the complexes (η⁵-C₅H₅)₂(CO)₂Fe₂(μ-CO)(η-C?PC₆H₂R₃-2,4,6) ( 9 a–c ) with edge-bridging isophosphaalkyne ligands as confirmed by the x-ray structure analysis of 9 a .     

Preparation and Characterization of an Unusual Di-Cobalt Complex; X-Ray Crystal Structure of Co(CO)2(μ-CO)(μ:η2,η4-C4Ph4)Co(CO)2(PPh3)

Reaction of [MoCo(CO)₅(PPh₃)₂(η⁵-C₅H₅)] (1) with diphenylacetylene in tetrahydrofuran at 50 °C yielded two heterobimetallic compounds, [MoCo(CO)₄.(PPh₃){μ-PhC ? CPh}(η⁵-C₅H₅)] (4) and [MoCo(CO)₅{μ-PhC ? CPh} (η⁵-C₅H₅)] (5). However, an unexpected product, Co(CO)₂(μ-CO)(μ:η₂,η⁴-C₄Ph₄)Co(CO)₂(PPh₃) (6), was observed while attempting to grow the crystals for structural determination of 4. The X-ray crystal structure of 6 was determined: triclinic, $ {\rm P}\bar 1 $, a = 11.654(2) Å, b = 12.864(2) Å, c = 13.854(2) Å, α = 89.67(2)°, β = 86.00(2)°, γ= 83.33(2)°, V = 2057.9(6) ų Z=2. In 6, two cobalt fragments are at apical and basal positions of the pseudo-pentagonal pyramidal structure, respectively. The electron count for the apical cobalt fragments is 20, which is rather unusual. It is believed that 6 was formed after the fragmentation and recombination of the fragmented species of 4.     

Preparation and Characterization of a Heteronuclear μ-Alkyne Complex; X-Ray Crystal Structure of MoCo(CO)4(PPh3){μ-HCCSiMe3)(η5-C5H5)

Reaction of MoCo(CO)₅(PPh₃)₂(η⁵-C₅H₅) (1a) with trimethylsilylacetylene in tetrahydrofuran at 58° C yielded two acetylene bridged heterobimetallic compounds, MoCo(CO)₄(PPh₃){μ-HC?CSiMe₃}(η⁵-C₅H₅) (4) and MoCo (CO)₅{μ-HC?CSiMe₃}(η⁵-C₅H₅)(5). (4) was characterized by mass, infrared, ¹H, ¹³C and ³¹P NMR spectra. The X-ray crystal structure of (4) was determined:triclinic, P-1, a=8.821(1) Å, b=11.315(3) Å, c=17.029(2) Å, α=70.73(1)°, β=78 .72(1)°, γ=86.10(2)°,V =1573.4(6) ų, Z=2, R = 3.92%,R_w = 6.06% for 4285 (F > 4σ (F)) observed reflections. The core of this molecule is a quasi-tetrahedron containing Mo, Co and two carbons of acetylene. The triphenylphosphine ligand is attached to cobalt rather than molybdenum center.     

Röntgenstrukturanalyse eines Carben-Additionsproduktes an Dicarbonyl-η5-methylcyclopentadienyl-Tetrahydrofuranmangan, μ-Cyclobuta[1, 2-a:3, 4-a′] dicyclopenten-bis[dicarbonyl-η5-methylcyclopentadienylmangan], [(η5-C5H4CH3)Mn (CO)2]2(μ2-C10H8)

X-Ray Structure Analysis of a Carbene Addition Product to Dicarbonyl-η⁵-methylcyclopentadienyltetrahydrofuranmanganese, μ-Cyclobuta[1, 2-a:3, 4-a′] dicyclopentene-bis-(dicarbonyl-η⁵-methylcyclopentadienylmanganese),[( η⁵-C₅H₄CH3)Mn(CO) ₂]₂(μ₂-C₁₀H₈) The crystal and molecular structure of the title compound has been determined by means of X-ray structure analysis. The species is the first example of an oligocyclic dicarbene stabilized by complex formation.     

Darstellung von μ-Hydrido-μ-diphenylphosphido-bis(tetracarbonylrhenium) · 1/2 Xylol und Molekülstruktur des Derivates Re2(CO)6(PPh3)2(μ-H)(μ-PPh2) (Ph = C6H5)

Preparation of μ-Hydrido-μ-diphenylphosphido-bis(tetracarbonylrhenium) · 1/2 Xylene and Molecular Structure of the Derivative Re₂(CO)₆(PPh₃)₂(μ-H)(μ-PPh₂) (Ph = C₆H₅) The reaction of dirhenium decacarbonyl with diphenylphosphine in xylene solution gave at 190–200°C in a glas tube crystals of Re₂(CO)₈(μ-H)(μ-PPh₂) · 1/2 C₈H₁₀. The obtained adduct was reacted in the same solvent with an excess of triphenylphosphine to the derivative Re₂(CO)₆(PPh₃)₂(μ-H)(μ-PPh₂). Both diamagnetic dirhenium compounds with μ-H atom and μ-PPh₂ group were characterized by ¹H and ³¹P spectroscopic measurements. The molecular structure of the derivative was acertained by a single crystal X-ray analysis. Its result showed a three-membered Re₂(μ-P) ring as central molecular fragment. At these Re central atoms were attached two PPh₃ ligands in an unprefered cis-arrangement due to sterical reasons. A thermodynamic transinfluence of the (μ-P)? Re bond favoured the found positions of the PPh₃ ligands.     

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.     

Synthesis of a transition metal-dithionite complex, (η5-C5H5)(CO)2FeS(O)2S(O)2Fe(CO)2(η5-C5H5)

The reaction of Na[η⁵-C₅H₅Fe(CO)₂] with large excess of SO₂ in THF at ?78°C followed by warming to room temperature affords an iron—dithionite complex, (η⁵-C₅H₅)(CO)₂FeS(O)₂S(O)₂Fe(CO)₂(η⁵-C₅H₅).     

Synthesis and characterization of complexes η5,η5-(CO)3Mn(C5H4-C5H4)(CO)2Fe-η1,η5-C5H4Mn(CO)3 and μ-(C≡C)[C5H4(CO)2Fe-η1,η5-C5H4Mn(CO)3]2

The complex η⁵,η⁵-(CO)₃Mn(C₅H₄-C₅H₄)(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃ was synthesized by the reaction of η⁵-Cp(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃ with BuⁿLi (THF, ?78 °C) and then with anhydrous CuCl₂. The complex μ-(C≡C)[C₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃]₂ was prepared by the reaction of η⁵-IC₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃ with Me₃SnC≡CSnMe₃ (2:1) in the presence of Pd(MeCN)₂Cl₂.     

Zur Reaktivität von Disilylarsenido-Eisenkomplexen gegenüber Carbonsäurechloriden Die ersten Arsaalkenyl- und Diacylarsenidokomplexe. Röntgen-Strukturanalyse von Z-[(η5-C5H5)(CO)2Fe?AsC(OSiMe3)(t-Bu)]

On the Reactivity of Disilylarsenido Iron Complexes towards Carbonyl Chlorides: The First Arsaalkenyl- and Diacylarsenido Complexes. X-Ray Structure Analysis of Z-[(η⁵-C₅H₅)(CO)₂Fe? As?C(OSiMe₃)(t-Bu)] The reaction of equimolar amounts of (η⁵-C₅H₅)(CO)₂FeAs(SiMe₃)₂ ( 1a ) with the carbonyl chlorides RC(O)Cl (R = t-Bu, 2,4,6-Me₃C₆H₂ and 2,4,6-t-Bu₃C₆H₂) yields the arsaalkenyl complexes Z-[(η⁵-C₅H₅)(CO)₂Fe? As?;C(OSiMe₃)R ( 2–4 )]. The diacylarsenido complexes (η⁵-C₅H₅)(CO)₂Fe? As[C(O)R]₂ ( 5, 6 ) are generated by treatment of 1a with two equivalents of pivaloyl chloride or mesitoyl chloride, respectively. The As?C-double bond length of 2 (1.821(2) Å) was determined by single crystal x-ray analysis.     

Preparation of new (η5-C5H4CH3)Mn(NO)(PPh3) and (η7-C7H7)Mo(CO)-(PPh3) complexes

The complex (η⁵-C₅H₄CH₃)Mn(NO)(PPh₃)I has been prepared by the reaction of NaI with [(η⁵-C₅H₄CH₃)Mn(NO)(CO)(PPh₃)]⁺ and also by the reaction of [(η⁵-C₅H₄CH₃)Mn(NO)(CO)₂]⁺ with NaI followed by PPh₃. This iodide compound reacts with NaCN to yield (η⁵-C₅H₄CH₃)Mn(NO)(PPh₃)CN which is ethylated by [(C₂H₅)₃O]BF₄ to yield [(η⁵-C₅H₄CH₃)Mn(NO)(PPh₃)(CNC₂H₅)]⁺. Both [(η⁵-C₅H₄CH₃)Mn(NO)(CO)₂]⁺ and [(η⁵-C₅H₄CH₃)Mn(NO)(PPh₃)(CO)]⁺ react with NaCN to yield [(η⁵-C₅H₄CH₃)Mn(NO)(CN)₂]^?. This anion reacts with Ph₃SnCl to yield cis-(η⁵-C₅H₄CH₃)Mn(NO)(CN)₂SnPh₃ and with [(C₂-H₅)₃O]BF₄ to yield [(η⁵-C₅H₄CH₃)Mn(NO)(CNC₂H₅)₂]⁺. The reaction of (η⁵-C₅-H₄CH₃)Mn(NO)(PPh₃)I with AgBF₄ in acetonitrile yields [(η⁵-C₅H₄CH₃)Mn-(NO)(PPh₃)(NCCH₃)]⁺. The complex (η⁵-C₅H₄CH₃)Mn(NO)(CO)I, produced in the reaction of [(η⁵-C₅H₄CH₃)Mn(NO)(CO)₂]⁺ with NaI, is not stable and decomposes to the dimeric complex (η⁵-C₅H₄CH₃)₂Mn₂(NO)₃I for which a reasonable structure is proposed. Similar dimers can be prepared from the other halide salts. The reaction of (η⁷-C₇H₇)Mo(CO)(PPh₃)I with NaCN yields (η⁷-C₇-H₇)Mo(CO)(PPh₃)CN which is ethylated by [(C₂H₅)₃O]BF₄ to yield [(η⁷-C₇H₇)-Mo(CO)(PPh₃)(CNC₂H₅)]⁺. The interaction of this molybdenum halide complex with AgBF₄ in acetonitrile and pyridine yields [(η⁷-C₇H₇)Mo(CO)(PPh₃)-(NCCH₃)]⁺ and [(η⁷-C₇H₇)Mo(CO)(PPh₃)(NC₅H₅)]⁺, respectively. Both (η⁵-C₅-H₄CH₃)Mn(NO)(PPh₃)I and (η⁷-C₇H₇)Mo(CO)(PPh₃)I are oxidized by NOPF₆ to the respective 17-electron cations in acetonitrile at ?78°C but revert to the neutral halide complex at room temperature. This result is supported by electrochemical data.     

Synthese,Struktur und Reaktivität von η3‐1,2‐Diphosphaallylkomplexen sowie von [{(η5‐C5H5)(CO)2W–Co(CO)3}{μ‐AsCH(SiMe3)2}(μ‐CO)]

Syntheses, Structure and Reactivity of η³‐1,2‐Diphosphaallyl Complexes and [{(η⁵‐C₅H₅)(CO)₂W–Co(CO)₃}{μ‐AsCH(SiMe₃)₂}(μ‐CO)] Reaction of ClP=C(SiMe₂iPr)₂ ( 3 ) with Na[Mo(CO)₃(η⁵‐C₅H₅)] afforded the phosphavinylidene complex [(η⁵‐C₅H₅)(CO)₂Mo=P=C(SiMe₂iPr)₂] ( 4 ) which in situ was converted into the η¹‐1,2‐diphosphaallyl complex [η⁵‐(C₅H₅)(CO)₂Mo{η³‐tBuPPC(SiMe₂iPr)₂] ( 6 ) by treatment with the phosphaalkene tBuP=C(NMe₂)₂. The chloroarsanyl complexes [(η⁵‐C₅H₅)(CO)₃M–As(Cl)CH(SiMe₃)₂] [where M = Mo ( 9 ); M = W ( 10 )] resulted from the reaction of Na[M(CO)₃(η⁵‐C₅H₅)] (M = Mo, W) with Cl₂AsCH(SiMe₃)₂. The tungsten derivative 10 and Na[Co(CO)₄] underwent reaction to give the dinuclear μ‐arsinidene complex [(η⁵‐C₅H₅)(CO)₂W–Co(CO)₃{μ‐AsCH(SiMe₃)₂}(μ‐CO)] ( 11 ). Treatment of [(η⁵‐C₅H₅)(CO)₂Mo{η³‐tBuPPC(SiMe₃)₂}] ( 1 ) with an equimolar amount of ethereal HBF₄ gave rise to a 85/15 mixture of the saline complexes [(η⁵‐C₅H₅)(CO)₂Mo{η²‐tBu(H)P–P(F)CH(SiMe₃)₂}]BF₄ ( 18 ) and [Cp(CO)₂Mo{F₂PCH(SiMe₃)₂}(tBuPH₂)]BF₄ ( 19 ) by HF‐addition to the PC bond of the η³‐diphosphaallyl ligand and subsequent protonation ( 18 ) and/or scission of the PP bond by the acid ( 19 ). Consistently 19 was the sole product when 1 was allowed to react with an excess of ethereal HBF₄. The products 6 , 9 , 10 , 11 , 18 and 19 were characterized by means of spectroscopy (IR, ¹H‐, ¹³C{¹H}‐, ³¹P{¹H}‐NMR, MS). Moreover, the molecular structures of 6 , 11 and 18 were determined by X‐ray diffraction analysis.     

Die Molekül- und Kristallstrukturen von (CO)4 W(μ-S-t-C4H9)2W(CO)4, η7-C7H7W(μ-SC6H4CH3)3W(CO)3 und η7-C7H7W(μ-S-n-C4H9)3W(CO)(μ-S-n-C4H9)2W(CO)4

Molecular and Crystal Structures of (CO)₄W(μ-S-t-C₄H₉)₂W(CO)₄, η⁷-C₇H₇W(μ-SC₆H₄CH₃)₃W(CO)₃ and η⁷-C₇H₇W(μ-S-n-C₄H₉)₃W(CO)(μ-S-n-C₄H₉)₂W(CO)₄ The molecular structures of the two binuclear complexes (CO)₄W(μ-S-t-C₄H₉)₂W(CO)₄ and η⁷-C₇H₇W(μ-SC₆H₄CH₃)₃W(CO)₃ and of the tungsten cluster η⁷-C₇H₇W(μ-S-n-C₄H₉)₃W(CO)-(μ-S-n-C₄H₉)₂W(CO)₄ respectively are described. In the nonlinear trinuclear cluster the central tungsten atom is connected to the two tungsten atoms by two and three μ-S-n-C₄H₉ bridges respectively and additionally by one W? W bond each. The coordination sphere of the W atoms is completed by a η⁷-C₇H₇ ring and four CO groups respectively; the central tungsten carries an additional CO group.     

Phosphido- und arsenido-verbrückte Zweikernkomplexe: Synthese und Struktur von (η5-C5H4R)2Zr{μ-P(SiMe3)2}2M(CO)4 (R = Me,M = Cr; R = H,M = Mo) sowie die Synthese von (η5-C5H5)2Zr{μ-As(SiMe3)2}2Cr(CO)4

Phosphido- and Arsenido-bridged Dinuclear Complexes. Synthesis and Molecular Structure of (η⁵-C₅H₄R)₂Zr{μ-P(SiMe₃)₂}₂M(CO)₄ (R = Me, M = Cr; R = H, M = Mo) and Synthesis of (η⁵-C₅H₅)₂Zr{μ-As(SiMe₃)₂}₂Cr(CO)₄ The reaction of (η⁵-C₅H₄R)₂Zr{E(SiMe₃)₂}₂ with M(CO)₄(NBD) (NBD = norbornadiene) yields the dinuclear phosphido- or arsenido-bridged complexes (η⁵-C₅H₄R)₂Zr{μ-E(SiMe₃)₂}₂M(CO)₄ (R = Me, E = P, M = Cr ( 1 ); R = H, E = P, M = Mo ( 2 ); R = H, E = As, M = Cr ( 3 )). No formation of dinuclear complexes was observed in the reaction of (η⁵-C₅H₄Me)₂Zr{P(SiMe₃)₂}₂ with Ni(PEt₃)₄, Ni(CO)₂(PPh₃)₂ or with NiCl₂(PPh₃)₂ in the presence of Mg. Complexes 1 – 3 were characterised spectroscopically (i. r., n. m. r., m. s.), and X-ray structure investigations were carried out on 1 and 2 . The central four-membered ZrP₂M ring is slightly puckered (dihedral angle between planes ZrP₂/CrP₂ 14.7°, ZrP₂/MoP₂ 14.2°). The Zr? P bond lengths are equivalent ( 1 : Zr? P1 2.654(4), Zr? P2 2.657(4) Å; 2 : Zr? P1 2.6711(9), Zr? P2 2.6585(7) Å), as are the M? P bond lengths (M = Cr ( 1 ): Cr? P1 2.513(4), Cr? P2 2.502(4) Å; M = Mo ( 2 ): Mo? P1 2.6263(7), Mo? P2 2.6311(10) Å). The long Zr ··· M distances of 3.414 Å (M = Cr ( 1 )) and 3.461 Å (M = Mo ( 2 )) indicate the absence of a metal-metal bond.     

Synthesis of μ-hydrido-μ-phosphido heterotrimetal alkylidyne clusters: X-ray crystal structure of [Co2W(μ-H)(μ3-CMe)(μ-PPh2)(CO)6(η-C5H5]

Treatment of the μ-alkylidyne clusters [Fe₂W(μ₃-CC₆H₄Me-4)(μ-CO)- (CO)₈(η-C₅H₅)] and [Co₂W(μ₃-CMe)(CO)₈(η-C₅H₅)] with PPh₂H affords a series of new μ-phosphido-μ-hydrido alkylidyne complexes which undergo protonation with HBF₄·Et₂O to give cationic derivatives. The X-ray structure of [Co₂W(μ-H)(μ₃-CMe)(μ-PPh₂)(CO)₆(η-C₅H₅)] has been determined.     

Sequential conversion of ethyne into μ-vinylidene, μ-methylcarbyne and μ-methylcarbene at a di-ruthenium centre: X-ray structures of [Ru2(CO)2(μ-CO) (μ-CCH2) (η-C5H5)2] and [Ru2(CO)2(μ-CO) (μ-CCH3) (η-C5H5)2] [BF4]

The ethyne-derived demetallocycle [Ru₂(CO) (μ-CO){μ-C(O)C₂H₂}(η-C₅H₅)₂ isomerises in boiling toluene to yield the μ-vinylidene complex [Ru₂(CO)₂(μ-CO)(μ-CCH₂) (η-C₅H₅)₂], which on protonation with dry HBF₄ provides the μ-carbyne complex [Ru₂(CO)₂(μ-CO)(μ-CCH₃)(η-C₅H₅)₂][BF₄]; the structure of each product has been determined by X-ray diffraction. The μ-carbyne cation is attacked by hydride to produce the μ-methylcarbene complex [Ru₂(CO)₂(μ-CO)(μ-CHCH₃)(η-C₅H₅)₂].     

Selektive Darstellung zweifach diorganophosphido-verbrückter Metallatetrahedrane [Re2(MPR3)2(μ-PR2)2(CO)6] mit Re2M2-Metallgerüst (M = Au,Ag)

Selective Preparation of Twofold Diorganophosphido-bridged Metallatetrahedranes [Re₂(MPR₃)₂(μ-PR₂)₂(CO)₆] with Re₂M₂ Metal Core (M = Au, Ag) The reaction of the in situ prepared salt Li[Re₂(AuPR)(μ-PR₂)(CO)₇Cl] (R = R′ = Cy ( 1 a ), R = Cy, R′ = Ph ( 1 b ), R = Ph, R′ = Cy ( 1 c ), R = Ph, R′ = Et ( 1 d ), R = Ph, R′ = Ph ( 1 e )) with one equivalent HPR in methanolic solution at room temperature yields the neutral cluster complexes [Re₂(AuPR)(μ-PR₂)(CO)₇(ax-HPR) (R = R′ = R″ = Cy ( 2 a ), Ph ( 2 b ), R = R′ = Cy, R″ = Et ( 2 c ), R = Cy, R′ = R″ = Ph ( 2 d ), R = Cy, R′ = Ph, R″ = Et ( 2 e ), R = R″ = Ph, R′ = Et ( 2 f ), R = Ph, R′ = Cy, R″ = Et (2 g)). Photochemically induced these complexes react in the presence of the organic base DBU in THF solution to give the doubly phosphido bridged anions Li[Re₂(AuPR)(μ-PR₂)(μ-PR)(CO)₆], which were characterized as salts PPh₄[Re₂(AuPR)(μ-PR₂)(μ-PR)(CO)₆] (R = R′ = R″ = Ph ( 3 a ), R = R′ = Ph, R″ = Cy ( 3 b ), R = Ph, R′ = Cy, R″ = Et ( 3 c ), R = R″ = Ph, R′ = Et ( 3 d )). These precursor complexes 3 then react with one equivalent of ClMPR (M = Au, Ag) to doubly phosphido bridged metallatetrahedranes [Re₂(MPR₃)₂(μ-PR₂)(μ-PR)(CO)₆] (M = Au, R = R′ = R″ = Ph ( 4 a ), M = Au, R′ = Et, R = R″ = Ph ( 4 b ), M = Au, R = R′ = Ph, R″ = Cy ( 4 c ), M = Au, R = Cy, R′ = Ph, R″ = Et ( 4 d ), M = Ag, R = R′ = R″ = Ph ( 4 e )). All isolated cluster complexes were characterized and identified by the following analytical methods: NMR- (¹H, ³¹P) and ν(CO) IR-spectroscopy and, additionally, complexes 2 b , 4 a and 4 e by X-ray structure analysis.     

Structural characterization of the anionic halfsandwich complex [Li(TMEDA)2][Mo(η5-C5H5)(CO)3] and its reactivity towards stannanes and distannanes

The crystal structure of the molybdenum half sandwich alkali salt [Li(TMEDA)₂][Mo(η⁵-C₅H₅)(CO)₃] shows the occurrence of a separated ion pair in the solid state. Furthermore, the crystal structures of the long known organotin complexes [Mo(η⁵-C₅H₅)(SnMe₃)(CO)₃], [{Mo(η⁵-C₅H₅)(CO)₃}₂SnMe₂] and [Mo(η⁵-C₅H₅)(SnMeCl₂)(CO)₃] have been recorded. The chlorination of [Mo(η⁵-C₅H₅)(SnMe₃)(CO)₃] with SnCl₄ is presented as an improved synthetic access to [Mo(η⁵-C₅H₅)(SnMeCl₂)(CO)₃]. Finally, the reaction of Li[Mo(η⁵-C₅H₅)(CO)₃] with ^tBu₂(Cl)Sn–Sn(Cl)^tBu₂ leads to the novel molybdenum distannane complex [Mo(η⁵-C₅H₅){Sn^tBu₂-Sn(Cl)^tBu₂}(CO)₃], which is fully characterized by NMR, elemental and X-ray analysis.