Zur Selektivität des isolobalen Protonenaustausches im Hydrido/Phosphidoverbrückten Dirhenium-Komplex Re2(μ-H)(μ-PCyH)(CO)8

On the Selectivity of the Isolobal Proton Exchange in the Hydrido/Phsophido Bridged Dirhenium Complex Re₂(μ-H)(μ-PCyH)(CO)₈ H₂PCy and Re₂(CO)₁₀ in Xylene were heated in a sealed glass tube at 170°C for 18 h to afford Re₂(μ-H)(μ-PCyH)(CO)₈ in a yield of 30% and the cis/trans isomer pair Re₂(μ-PCyH)₂(CO)₈ in yields of 27% (trans) and 21% (cis). The isomer trans Re₂(μ-PCyH)₂(CO)₈ could be partially converted to the cis isomer by deprotonation with the non nucleophilic base DBU or by heating in xylene solution. The complex Re₂(μ-H)(μ-PCyH)(CO)₈ which is bifunctional relative to a proton abstraction was treated with equimolar amounts of DBU to generate [Re₂(μ-H)(μ-PCy)(CO)₈]^? under release of the more acidic proton from the PH group. Subsequently, this anion undergoes an isomerization to the thermodynamically more stable [Re₂(μ-PCyH)(CO)₈]^? by proton transfer. Such knowledge about the isomeric anions enabled us to synthesize selectively the monoaurated isomers Re₂(μ-AuPPh₃)(μ-PCyH)(CO)₈ and Re₂(μ-H)(μ₃-PCy(AuPPh₃))(CO)₈ in good yields by reaction with equimolar amounts of the electrophil ClAuPPh₃. In the presence of excess DBU and a twofold amount of ClAuPPh₃ the complex Re₂(μ-H)(μ-PCyH) · (CO)₈ formed the diaurated complex Re₂(μ-AuPPh₃)(μ₃-PCy(AuPPh₃))(CO)₈ (91%). Compared to the corresponding known dimanganese-gold isomers, each of the analogous dirhenium-gold complexes obtained showed no tendency for an isomerization process. Finally, the single crystal X-ray analyses of the three dirhenium-gold complexes led to the subsequent Re? Re bond lengths: 313,6(1) pm in Re₂(μ-H)(μ₃-PCy(AuPPh₃))(CO)₈, 316,8(2) pm in Re₂(μ-AuPPh₃)(μ₃PCy(AuPPh₃))(CO)₈ and 326,1(2) pm in Re₂(μ-AuPPh₃)(μ-PCyH)(CO)₈.     

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.     

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.     

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.     

Vierkernige Clusterkomplexe vom Typ [MM′(AuPR3)2(μ‐H)(μ‐PCy2)(μ4‐PCy)(CO)6] (M,M′ = Mn,Re; R = Ph,Cy, Et): Synthese,Struktur und Topomerisierung

Tetranuclear Cluster Complexes of the Type [MM′(AuR₃)₂(μ‐H)(μ‐PCy₂)(μ₄‐PCy)(CO)₆] (M,M′ = Mn, Re; R = Ph, Cy, Et): Synthesis, Structure, and Topomerisation The dirhenium complex [Re₂(μ‐H)(μ‐PCy₂)(CO)₇(ax‐H₂PCy)] ( 1 ) reacts at room temperature in thf solution with each two equivalents of the base DBU and of ClAuPR₃ (R = Ph, Cy, Et) in a photochemical reaction process to afford the tetranuclear clusters [Re₂(AuPR₃)₂(μ‐H)(μ‐PCy₂)(μ₄‐PCy)(CO)₆] (R = Ph ( 2 ), Cy ( 3 ), Et ( 4 )) in yields of 35–48%. The homologue [Mn₂(μ‐H)(μ‐PCy₂)(CO)₇(ax‐H₂PCy)] ( 5 ) leads under the same reaction conditions to the corresponding products [Mn₂(AuPR₃)₂(μ‐H)(μ‐PCy₂)(μ₄‐PCy)(CO)₆] (R = Ph ( 6 ), Et ( 8 )). Also [MnRe(μ‐H)(μ‐PCy₂)(CO)₇(ax/eq‐H₂PCy)] ( 9 ) reacts under formation of [MnRe(AuPR₃)₂(μ‐H)(μ‐PCy₂)(μ₄‐PCy)(CO)₆] (R = Ph ( 10 ), Et ( 11 )). All new cluster complexes were identified by means of ¹H‐NMR, ³¹P‐NMR and ν(CO)‐IR spectroscopic measurements. 2 , 4 and 10 have also been characterized by single crystal X‐ray structure analyses with crystal parameters: 2 triclinic, space group P 1, a = 12.256(4) Å, b = 12.326(4) Å, c = 24.200(6) Å, α = 83.77(2)°, β = 78.43(2)°, γ = 68.76(2)°, Z = 2; 4 monoclinic, space group C2/c, a = 12.851(3) Å, b = 18.369(3) Å, c = 40.966(8) Å, β = 94.22(1)°, Z = 8; 10 triclinic, space group P 1, a = 12.083(1) Å, b = 12.185(2) Å, c = 24.017(6) Å, α = 83.49(29)°, β = 78.54(2)°, γ = 69.15(2)°, Z = 2. The trapezoid arrangement of the metal atoms in 2 and 4 show in the solid structure trans‐positioned an open and a closed Re…Au edge. In solution these edges are equivalent and, on the ³¹P NMR time scale, represent two fluxional Re–Au bonds in the course of a topomerization process. Corresponding dynamic properties were observed for the dimanganese compounds 6 and 8 but not for the related MnRe clusters 10 and 11 . 2 and 4 are the first examples of cluster compounds with a permanent Re–Au bond valence isomerization.     

Reactivity of the unsaturated dimolybdenum anion [Mo2(η-C5H5)2(μ-PCy2)(μ-CO)2] towards electrophiles based on p- and d-block elements

The 30-electron binuclear anion [Mo₂Cp₂(μ-PCy₂)(μ-CO)₂]⁻ reacts with the chlorophosphite ClP(OEt)₂ or the organotin chlorides Cl₂SnPh₂ or ClSnPh₃ to give compounds of the formula trans-[Mo₂Cp₂(μ-E)(μ-PCy₂)(CO)₂], (E = P(OEt)₂, SnPh₃, SnPh₂Cl). In contrast, this anion reacts with the organosilicon chlorides ClSiR₃ (R = Ph, Me) to give unstable silyloxycarbyne-bridged complexes [Mo₂Cp₂(μ-PCy₂)(μ-COSiR₃)(μ-CO)], which rapidly hydrolyze to give the known hydride [Mo₂Cp₂(μ-H)(μ-PCy₂)(CO)₂]. Two main types of products were also observed in the reactions of the title anion with different chlorocomplexes of the transition and post-transition metals. Thus, the reactions with [MCl₂Cp₂] (M = Ti, Zr) give moisture-sensitive isocarbonyl-bridged complexes of the type [Mo₂Cp₂(μ-COMClCp₂)(μ-PCy₂)(μ-CO)]. In contrast, softer metallic electrophiles such as [AuCl(PR₃)] (R = ⁱPr, ptol) react with the anion at the dimolybdenum site to form new trimetallic clusters of the formula [AuMo₂Cp₂(μ-PCy₂)(CO)₂(PR₃)], also retaining a Mo−Mo triple bond. Subsequent reactions of the latter products with the solvate complexes [Au(PR₃)(THF)][PF₆] give the tetranuclear clusters [Au₂Mo₂Cp₂(μ-PCy₂)(CO)₂(PR₃)₂][PF₆] (Mo−Mo = 2.5674(3) Å and Au−Au = 2.7832(2) Å when R = ⁱPr). Finally, the reaction of the title anion with HgI₂ gives the pentanuclear cluster [Hg{Mo₂Cp₂(μ-PCy₂)(CO)₂}₂] or the trinuclear cluster [Mo₂Cp₂(μ-HgI)(μ-PCy₂)(CO)₂] depending on the stoichiometry being actually used for the reaction. The trinuclear species is only stable in tetrahydrofuran (THF), and decomposes to give a mixture of the dimeric species [Mo₂Cp₂(μ-HgI)(μ-PCy₂)(CO)₂]₂ along with variable amounts of the known iodide-bridged complex [Mo₂Cp₂(μ-I)(μ-PCy₂)(CO)₂].     

Isolobal replacement of the metal fragments in [Fe3(μ3-Q)(μ3-AsCH3)(CO)9] (Q = Se and Te): Synthesis and structures of a number of Fe-Ir and Fe-Rh clusters simultaneously containing a chalcogen and arsenic

Cothermolysis of the clusters [Fe₃(μ₃-Q)(μ₃-AsCH₃)(CO)₉] (Q = Se and Te) and the complexes [Cp*M(CO)₂] (M = Rh and Ir) was accompanied by isolobal replacement of the fragment {Fe(CO)₃} by {Cp*M}; the final reaction products were [Fe₂M(μ₃-Q)(μ₃-AsCH₃)(CO)₆Cp*]. For M = Ir, these reactions involved addition of an iridium fragment to the starting cluster to give the intermediate adducts [Fe₃Ir(μ₄-Q)(μ₄-AsCH₃)(CO)₈Cp*]. In the case of [Cp*Rh(CO)₂], the intermediate tetranuclear rhodium adducts were also isolated. Sets of these adducts differed for the selenide ([Fe₃Rh(μ₄-Se)(μ₄-AsMe)(CO)₈Cp*] and [Fe₂Rh₂(μ₃-Se)(μ₄-AsMe)(CO)₆Cp₂^*]) and telluride clusters ([Fe₃Rh(μ₄-Te)(μ₃-AsMe)(μ-CO)(CO)₉Cp*] and [Fe₃Rh₂(μ₃-Te)(μ₄-AsMe)(μ₃-CO)(μ-CO)(CO)₈Cp₂^*]). The structures of all 10 novel heterometallic clusters were determined by single-crystal X-ray diffraction analysis. Original Russian Text ? N.A. Pushkarevskii, D.A. Bashirov, A.V. Litke, A.V. Virovets, N.V. Kurat’eva, M. Scheer, S.N. Konchenko, 2008, published in Koordinatsionnaya Khimiya, 2008, Vol. 34, No. 12, pp. 883–895.     

Preparation and reactivity of metal-containing monomers 53. Synthesis and stability of a cluster monomer (μ-H)Os3(μ-OCNMe2)(CO)9PPh2CH2CH=CH2 in solution

The stability of the complex (μ-H)Os₃(μ-OCNMe₂)(CO)₉PPh₂CH₂CH=CH₂ (1), which contains a free unsaturated functional group in the terminal ligand PPh₂CH₂CH=CH₂, with respect to isomerization, chelation of the ligand, and other transformations in solutions was examined. No transformations of complex1 were observed in the course of synthesis from (μ-H)Os₃(μ-OCNMe₂)(CO)₉NMe₃ or upon heating in solution. Complex1 as well as complexes (μ-H)Os₃(μ-OCNMe₂)(CO)₉PHPh₂ and (μ-H)Os₃(μ-OCNMe₂)(CO)₉PPh₃, which were formed as admixtures, were isolated in the solid state and identified by¹H,¹H-{³¹P}, and¹H-{¹H} NMR, IR, and Raman spectroscopy and mass spectrometry. For Part 52, see Ref. 1. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1455–1460, August, 2000.     

An Electron-Deficient Triosmium Cluster Containing the Thianthrene Ligand: Synthesis, Structure and Reactivity of [Os3(CO)9(μ3-η2-C12H7S2)(μ-H)]

Reaction of [Os₃(CO)₁₀(CH₃CN)₂] with thianthrene at 80 °C leads to the nonacarbonyl dihydride compound [Os₃(CO)₉(μ-3,4-η²-C₁₂H₆S₂)(μ-H)₂] (1) and the 46-electron monohydride compound [Os₃(CO)₉(μ₃-η²-C₁₂H₇S₂)(μ-H)] (2). Compound 2 reacts reversibly with CO to give the CO adduct [Os₃(CO)₁₀(μ-η²-C₁₂H₇S₂)(μ-H)] (3) whereas with PPh₃ it gives the addition product [Os₃(CO)₉)(PPh₃)(μ-η²-C₁₂H₇S₂)(μ-H)] (4) as well as the substitution product 1,2-[Os₃(CO)₁₀((PPh₃)₂] (5) Compound 2 represents a unique example of an electron-deficient triosmium cluster in which the thianthrene ring is bound to cluster by coordination of the sulfur lone pair and a three-center-two-electron bond with the C(2) carbon which bridges the same edge of the triangle as the hydride. Electrochemical and DFT studies which elucidate the electronic properties of 2 are reported. Dedicated to the memory of a great scientist, F. Albert Cotton.     

Synthesis of ferrocenylacetylide derivatives of gold-ruthenium and gold-osmium clusters. Crystal structures of M3(AuPPh3)(C≡CFc)(CO)9 (M=Ru or Os; Fc is ferrocenyl)

The synthesis and crystal structures of the clusters M₃(AuPPh₃)(C≡CFc)(CO)₉ (M=Ru,3a; or M=Os,3b) are described. Compound3a was synthesized by deprotonation of Ru₃H(C≡CFc)(CO)₉ under the action of KOH/EtOH followed by treatment of the anionic complex [Ru₃(C≡CFc)(CO)₉]⁻ with chloro(triphenylphosphine)gold. Compound3b was prepared by the reaction of Os₃(CO)₁₀(NCMe)₂ with FcC≡CAuPPh₃, which was synthesized by the reaction of FcC≡CNa with ClAuPPh₃. The pentanuclear cluster Ru₄(AuPPh₃)(C≡CFc)(CO)₁₂ (4a), which was prepared by the reaction of3a with Ru₃(CO)₁₂, was characterized by spectral methods. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1295–1299, July, 2000.     

Synthesis and structures of nickel(II) trimethylacetate dimers with coordinated diamines

Thermal decomposition of the tetranuclear nickel(II) complex Ni₄lη²-o-(NH₂)(NHPh)C₆H₄|₂(MeCN)₂(μ-OOCCMe₃)₄(η²-OOCCMe₃)₂ (I) under an inert atmosphere (o-xylene, 140 °C) was investigated. Under these conditions, the asymmetric binuclear complex Ni|η²-o-(NH₂)(NHPh)C₆H₄‖(η¹-o-(NH₂))(NHPh)C₆H₄|(η²,η-O,O-OOCCMe₃)(η²-OOCCMe₃) (2) was formed at the first stage. Complex2 was converted into the symmetric dimer Ni|η¹-o-(NH₂)(NHPh)C₆H₄|(μ-OOCCMe₃)₄ (3) upon recrystallization from benzene. The structures of complexes2 and3 were established by X-ray diffraction analysis. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1915–1918, November, 2000.     

Recent studies on chemistry of novel μ-CO-containing butterfly Fe/E (E=S,Se,Te) cluster salts

This article describes recent developments in chemical study on a series of butterfly-shaped μ-CO-containing Fe/E (E = S, Se, Te) cluster salts. These salts include eleven novel cluster anions, which are the single butterfly one μ-CO-containing [(μ-RE)(μ-CO)Fe2(CO)6]- (A), the double butterfly two μ-CO-containing {[(μ-CO)Fe2(CO)6]2(μ-EZE-μ)}2- (B, E = S; C, E = Se), the triple butterfly three μ-CO- containing {[(μ-CO)Fe2(CO)6]3[(μ-SCH2CH2)3N]}3- (D), {[(μ-CO)Fe2(CO)6]3[1,3,5-(μ-SCH2)3C6H3]}3- (E), {[(μ- CO)...     

Synthesis and characterization of stable thiazolylazo anion radical complexes of ruthenium(II)

Two stable thiazolylazo anion radical complexes of ruthenium(II), [Ru(L1^•−)(Cl)(CO)(PPh₃)₂] (1) and [Ru(L2^•−)(Cl)(CO)(PPh₃)₂] (2) (where L1 = 2′-Thiazolylazo-2-imidazole and L2 = 4-(2′-Thiazolylazo)-1-n-hexadecyloxy-naphthalene), have been synthesized and characterized by spectroscopic and electrochemical techniques. The radical nature of the complexes has been confirmed from their room temperature magnetic moments and X-band ESR spectra. The radical complexes display a moderately intense (ε ~ 10⁴ M⁻¹ cm⁻¹) and relatively broad band in 430–460 nm region. In the microcrystalline state, complexes (1) and (2) display strong ESR signals at g = 1.951 and g = 1.988, respectively. In CH₂Cl₂ solution, complexes (1) and (2) show a quasireversible one-electron response near −0.64 and −0.59 V, respectively, versus Ag/AgCl due to the radical redox couple [Ru^II(L)(Cl)(CO)(PPh₃)₂]/[Ru^II (L^•−)(Cl)(CO)(PPh₃)₂].     

Study of allylic rearrangement in (μ-H)Os3(μ-O=CNRCH2CH=CH2)(CO)10 (R=H or CH3) clusters

The migration of the double bond in the allylcarboxamide ligands of (μ-H)Os₃(μ-O=CN RCH₂CH=CH₂) (CO)₁₀ (R=H (1) or CH₃ (2)), (μ-D)Os₃(μ-O=CNDCH₂CH=CH₂) (CO)₁₀, and (μ-H)Os₃(μ-O=CNHCD₂CH=CH₂)(CO)₁₀ clusters was studied by¹H,²H, and¹³C NMR spectroscopy. Neither μ-D nor ND groups in the deuterated complexes are directly involved in prototropic processes of allylic rearrangement. Initially, the deuterium atom of the CD₂ group migrates to the ψ-carbon atom of the allyl fragment to form the −CD=CH-CH₂D propenyl moiety, in which the deuterium and hydrogen atoms are gradually redistributed between the ψ-and β-carbon atoms. The triosmium cluster complexes containing the bridging carboxamide ligands O=CNRR' catalyze the allylic rearrangement ofN-allylacetamide. Based on the data obtained, the probable scheme of the allylic rearrangements in clusters1 and2 was proposed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2182–2186, November, 1999.     

Heterodinukleare Komplexe: Synthese und Kristallstrukturen von [RuRh(μ‐CO)(CO)4(μ‐PtBu2)(tBu2PH)], [RuRh(μ‐CO)(CO)3(μ‐PtBu2)(μ‐Ph2PCH2PPh2)] und [CoRh(CO)4(μ‐H)(μ‐PtBu2)(tBu2PH)]

Heterobinuclear Complexes: Synthesis and X‐ray Crystal Structures of [RuRh(μ‐CO)(CO)₄(μ‐P^tBu₂)(^tBu₂PH)], [RuRh(μ‐CO)(CO)₃(μ‐P^tBu₂)(μ‐Ph₂PCH₂PPh₂)], and [CoRh(CO)₄(μ‐H)(μ‐P^tBu₂)(^tBu₂PH)] [Ru₃Rh(CO)₇(μ₃‐H)(μ‐P^tBu₂)₂(^tBu₂PH)(μ‐Cl)₂] ( 2 ) yields by cluster degradation under CO pressure as main product the heterobinuclear complex [RuRh(μ‐CO)(CO)₄(μ‐P^tBu₂)(^tBu₂PH)] ( 4 ). The compound crystallizes in the orthorhombic space group Pcab with a = 15.6802(15), b = 28.953(3), c = 11.8419(19) Å and V = 5376.2(11) ų. The reaction of 4 with dppm (Ph₂PCH₂PPh₂) in THF at room temperature affords in good yields [RuRh(μ‐CO)(CO)₃(μ‐P^tBu₂)(μ‐dppm)] ( 7 ). 7 crystallizes in the triclinic space group P 1 with a = 9.7503(19), b = 13.399(3), c = 15.823(3) Å and V = 1854.6 ų. Moreover single crystals of [CoRh(CO)₄(μ‐H)(μ‐P^tBu₂)(^tBu₂PH)] ( 9 ) could be obtained and the single‐crystal X‐ray structure analysis revealed that 9 crystallizes in the monoclinic space group P2₁/a with a = 11.611(2), b = 13.333(2), c = 18.186(3) Å and V = 2693.0(8) ų.     

Preparation and Structures of Several Complexes Containing Carbon-Rich Ligands Attached to Polynuclear Metal Carbonyls

Several new gold-containing cluster complexes have been prepared from the reactions of gold alkynyl complexes, L _n M-C _x -Au(PPh₃), (x = 3, 4, 6) with Ru₃(CO)₁₀(NCMe)₂. The bis-cluster complex 1,4-{AuRu₃(CO)₉(PPh₃)(μ₃-C₂)}₂C₆H₄ was obtained from Ru₃(CO)₁₀(NCMe)₂ and 1,4-{(Ph₃P)Au(C≡C)}₂C₆H₄. The complexes Ru₃(μ-H){μ₃-C₂C≡C[Ru(PP)Cp′]}(CO)₉ [PP = (PPh₃)₂, Cp′ = Cp; PP = dppe, Cp′ = Cp*] were also obtained as minor by-products and synthesised independently from Ru(C≡CC≡CH)(PP)Cp′. A reaction between Co₃{μ₃-CC≡CC≡CAu(PPh₃)}(μ-dppm)(CO)₇ and Ru₃(CO)₁₂ afforded {(Ph₃P)(OC)₉AuRu₃}C≡CC≡CC{Co₃(μ-dppm)(CO)₇} 7. Related complexes AuRu₃{μ₃-C₂C≡[M(CO)₂Tp]}(CO)₉(PPh₃) (M = Mo 8, W 9) were obtained from {Tp(OC)₂M}≡CC≡C{Au(PPh₃)}, while the mixed metal cluster complexes MoM₂(C₂Me)(CO)₈Tp (M = Ru 13, Fe 14) were obtained from M(≡CC≡CSiMe₃)(CO)₂Tp (M = Mo, W) with Fe₂(CO)₉ and Ru₃(CO)₁₂, respectively. Reactions of the Mo carbyne complex with Co₂(LL)(CO)₆ [LL = (CO)₂, μ-dppm] or nickelocene afforded complexes 15–17 in which Co₂ and Ni₂ fragments, respectively, had coordinated to the C≡C triple bond. XRD structural determinations of 7, 8, 14, 16 and {Tp(OC)₂W}≡CC≡CC≡{Co₃(μ-dppm)(CO)₇} (18-W) are reported. In memoriam: F. Albert Cotton (1930–2007).     

Polynuclear nitrosyl carbonyl ReI complexes with thiolate and sulfide bridges

The reaction of the complex Re₂(CO)₄(NO)₂Cl₄ (1) with NaSCMe₃ (2) (in THF or MeCN, 65–80°C, 24 h) was studied at different ratios of the reagents (from 1∶2 to 1∶6). At the reagent ratio of 1∶2, the binuclear complex Re₂(CO)₄(NO)₂Cl₂(μ-SCMe₃)₂ (3) was obtained as a mixture ofsyn andanti isomers (3a and3b, respectively) containing Re₂S₂ fragments with different structures (the butterfly-like structure in3a and the planar fragment in3b). When the initials were taken in ratios from 1∶4 to 1∶6, two compounds were isolated: the binuclear complex Re₂(CO)₄(NO)₂(μ-SCMe₃)₂(μ-S)4 (cocrystallized as a mixture ofsyn andanti isomers,4a and4b, respectively) and the triangular cluster Re₃(CO)₃(NO)₃(μ-SCMe₃((μ₃-S)(μ₃-Cl) (5). Apparently, complex4 is formed in the course of isolation as a result of elimination of SR₂ from the unstable tetrathiolate dimer Re₂(CO)₄(NO)₂(SCMe₃)₂(μ-SCMe₃)₂ (6). Cluster5 is the product of the reaction between compounds3 and4. Products of interaction of compound6 with silica gel upon column chromatography of the reaction mixture were studied. Four complexes containing hydroxy and oxo bridging groups, (CO)₂(NO)Re(μ-SCMe₃)₂(μ-OH)Re(SCMe₃)(CO)(NO) (7), (CO)₃(NO)₃RE₃(μ-SCMe₃)₃(μ₃-SCME₃)(μ₃-O) (8), [(CO)₂(NO)₂Re₂(SCMe₃)₂(μ-SCMe₃)₂(μ-OH)][Na(THF)(Et₂O)] (9), and [(CO)₂(NO)₂Re₂(SCMe₃)₂(μ-SCMe₃)₂(μ-OH)]₂−[Na(H₂O)₆][H₅O₂] (10), were isolated. The structures of complexes3, 4, 5, 7, 8, 9, and10 were established by X-ray diffraction study. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1030–1044, May, 1998.     

Reactivity of the 30-electron dimolybdenum anion [Mo2(η-C5H5)2(μ-PCy2)(μ-CO)2] towards β,γ-unsaturated organic halides: Alkenyl, allenyl and alkoxycarbyne derivatives

The 30-electron dimolybdenum anion [Mo₂Cp₂(μ-PCy₂)(μ-CO)₂]⁻ reacts at room temperature with allyl chloride to give the unsaturated σ:π-bonded alkenyl derivative trans-[Mo₂Cp₂(μ-η¹:η²-CMeCH₂)(μ-PCy₂)(CO)₂], this requiring a 2,1-hydrogen shift in the allyl moiety probably induced by the unsaturated nature of the dimetal center. In a similar way, the dimolybdenum anion reacts with trans-1-chloro-2-butene (crotyl chloride) to give a mixture of the alkenyl complexes trans-[Mo₂Cp₂(μ-η¹:η²-CEtCH₂)(μ-PCy₂)(CO)₂] and trans-[Mo₂Cp₂(μ-η¹:η²-CMeCHMe)(μ-PCy₂)(CO)₂] in a 3:2 ratio, which could not be separated by column chromatography. All these alkenyl species exhibit a dynamic behavior in solution (fast on the NMR timescale even at low temperatures) involving alternative π-bonding of the alkenyl ligand to each metal center. In contrast, the title anion reacts with propargyl chloride (ClCH₂-CCH) without further rearrangement of the propargyl moiety, to afford the allenyl derivative trans-[Mo₂Cp₂{μ-η²:η³-CH₂CCH)}(μ-PCy₂)(CO)₂] as the major species. Acryloyl chloride (ClC(O)-CHCH₂) also reacts with the title anion to give a mixture of two products, the carbyne complex [Mo₂Cp₂{μ-COC(O)CHCH₂}(μ-PCy₂)(μ-CO)] and the vinyl trans-[Mo₂Cp₂(μ-η¹:η²-CHCH₂)(μ-PCy₂)(CO)₂], in a 1:1 ratio. This reaction is a unique case in which a single electrophile can attack both nucleophilic positions in the dimolybdenum anion, these being located at the O(carbonyl) and metal sites, respectively. The formation of the vinyl derivative requires the decarbonylation of a metal-bound acryloyl group, which proved to be an irreversible reaction, since the addition of CO to the above alkenyl complex gave instead the tricarbonyl vinyl derivative cis-[Mo₂Cp₂(μ-η¹:η²-CHCH₂)(μ-PCy₂)(CO)₃]. The structure of this electron-precise complex was confirmed through a single-crystal X-ray diffraction analysis (Mo−Mo = 3.0858(7) Å).     

Synthesis and characterization of the [Ru(η5-C5Me4CF3)(CO)2]2 and Ru6(μ3-H)(η2-μ4-CO)2(μ-CO)(CO)12(η5-C5Me4CF3) complexes

The reaction of Ru₃(CO)₁₂ with tetramethyltrifluoromethylcyclopentadiene at various ratios of the reagents was studied. Refluxing of Ru₃(CO)₁₂ with a sixfold excess of tetramethyltrifluoromethylcyclopentadiene in octane in an inert atmosphere gave a complex, which is, according to X-ray diffraction data, a dimer,trans-[Ru(η⁵-C₅Me₄CF₃)(CO)₂]₂. The reaction under the same conditions but starting from Ru₃(CO)₁₂ and C₅Me₄CF₃H in 2∶1 molar ratio gave a hexaruthenium cluster [Ru₆(μ₃-H)(η₂-μ₄-CO)₂(μ-CO)(Co)₁₂(η⁵-C₅Me₄CF₂)], which was characterized by IR as well as¹H,¹³C, and¹⁹F NMR spectroscopy. According to X-ray diffraction data, an Ru₄ tetrahedron, in which two edges are bound by additional “briding” Ru atoms, constitutes the frame of this compound. This complex has one (η⁵-C₅Me₄CF₃) ligand, as well as one (μ₃-H) and two (η²-μ₄-CO) groups. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 507–512, March, 1998.     

Seven-coordinate complexes of molybdenum(II) and tungsten(II) containing pyrazole as a ligand

Summary Equimolar quantities of [MI₂(CO)₃(NCMe)₂] (M = Mo or W) and C₃H₄N² (pyrazole) react in CH₂C1₂ at room temperature to give the iodo-bridged dimers [M(μ-I) (CO)₃(C₃H₄N²)]₂ (1) and (2). Two equivalents of C₃H₄N² react with [MI₂(CO)₃(NCMe)₂] (M = Mo or W) to give the bis(pyrazole) complexes [MI₂(CO)₃(C₃H₄N²)₂] (3) and (4) in good yield. Three and four equivalents of pyrazole react with [MoI₂(CO)₃(NCMe)₂] to give the cationic complexes [MoI(CO)₃(C₃H₄N²)₃]I (5) and [MoI(CO)₂(C₃H₄N²)₄]I (6), respectively. The mixed ligand complexes [MI₂(CO)₃(C₃H₄N²)L] (M = Mo or W; L = PPh₃, AsPh₃ or SbPh₃) (7)-(12) are prepared by reacting equimolar amounts of [MI₂(CO)₃(NCMe)₂] and L in CH₂C1₂ at room temperature, followed by an in situ reaction with one equivalent of C₃H₄N². The MoSnCl₃ complex [MoCl(SnCl₃)(CO)₃(C₃H₄N²)₂] (13) is prepared in an analogous manner using acetone as the solvent, whilst the mixed ligand compound [MoCl(SnQ₃)(CO) ₃(C₃H₄N²)(PPh₃)] (14) was prepared by treating the dimeric complex [Mo(μ-Cl)(SnCl₃)(CO)₃(PPh₃)]₂ with two equivalents of C₃H₄N². All the new complexes were characterised by elemental analysis (carbon, hydrogen and nitrogen), i.r. and ¹H n.m.r. spectroscopy.