Synthesis and X-ray crystal structure of the electron-deficient metal carbonyl cluster [Os3(CO)5(μ3-H)(μ-H)(μ-PtBu2)2(μ-Ph2PCH2PPh2)]

The reaction of [Os₃(CO)₁₀(μ-dppm)] (1) with ^tBu₂PH in refluxing diglyme results in the electron-deficient metal cluster complex [Os₃(CO)₅(μ₃-H)(μ-P^tBu₂)₂(μ-dppm)] (2) (dppm = Ph₂PCH₂PPh₂) in good yields. The molecular structure of 2 has been established by a single crystal X-ray structure analysis. In contrast to the known homologue [Ru₃(μ-CO)(CO)₄(μ₃-H)(μ-H)(μ-P^tBu₂)₂(μ-dppm)] (3), no bridging carbonyl ligand was found in 2. The electronically unsaturated cluster 2 does not react with carbon monoxide under elevated pressure, therefore 2 seems to be coordinatively saturated by reason of the high steric demands of the phosphido ligands.     

Redox behavior of trinuclear M3(μ-H)(μ3-μ1:μ2:μ2-C2Fe)(Co)9 and tetranuclear RuM3 3(μ-H)(μ4-μ1:μ1:μ1:μ2-C2Fe)(Co)12 (M=Ru or Os; and Fc=ferrocenyl) clusters. Electronic interaction between the ferrocenylacetylide ligand and the metal core of the cluster

The redox properties of the clusters Ru₃(CO)₁₂(1), Ru₃(μ-H)(μ₃-μ¹:μ²:μ²-C₂Fe)(CO)₉ (2), OS₃(μ-H)(μ₃-μ¹:μ²:μ²-C₂Fe)(CO)₉ (3), Ru₄(μ-H)(μ₄-μ¹:μ¹:μ¹:μ²-C₂Fe)(CO)₁₂ (4), and RuOS₃(μ-H)(μ₄-μ¹:μ¹:μ¹:μ²-C₂Fe)(CO)₁₂ (5) in THF have been studied by cyclic voltammetry in the temperature range from ?60 to +20°C. It was demonstrated that reversible one-electron oxidation of the ferrocenyl fragment in clusters 2–5 occurs at more positive potentials (δE ⁰=0.15–0.26 V) than that of free ferrocene. This is indicative of the electron-withdrawing character of the cluster core with respect to the ferrocenylacetylide ligand. The electron-withdrawing effect of the metal core is more pronounced in tetranuclear clusters4 and 5 than in trinuclear clusters2 and3. Unlike complexes1–3, which undergo irreversible reduction, complexes4 and5 undergo reversible one-electron reduction to form the corresponding radical anions4 ^? and5 ^?.     

The Kornblum Reaction of α-Substituted 3-Benzyl-1,2-dihydro-2-oxoquinoxalines. Synthesis and Structure of 3-Benzoyl-2-oxo-1,2-dihydroquinoxaline

A method has been developed for the preparation of 3-benzoyl-2-oxo-1,2-dihydroquinoxaline by the reaction of 3-(-chlorobenzyl)-1,2-dihydroquinoxaline under Kornblum reaction conditions to the corresponding -azido derivative and then acid fission of the latter. The structure of the target ketone has been confirmed by X-ray analysis.     

Synthesis of the 1,2-Dihydro 1,2-Δ3−azaphosphorines

Abstract

1,2-Dihydro 1,2-Δ³? azaphosphorines were prepared by reaction of dichlorophenylphosphine with two equivalents of imines. 2-Oxo 1,2-azaphospholenes were also obtained in some cases.     

Reactions of γ-Sultines with Electrophilic Reagents. 3. Chlorination of 3,5-Diaryl-1,2-oxathiolane 2-Oxides

The influence of the nature of the aryl substituents and the reaction conditions for the chlorination of 3,5-diphenyl-1,2-oxathiolane 2-oxide and 3,5-bis(4-methoxyphenyl)-1,2-oxathiolane 2-oxide have been studied. Possible mechanisms for the chlorination of -sultines are discussed.     

Reactions of the unsaturated anion [Re3(μ-H)4(CO)10]− with phosphines. Synthesis of the anions [Re3(μ-H)2(CO)10(PR3)2]−, and crystal structure of [NEt4][Re3(μ-H)2(CO)10(PPh3)2]

The reaction of the unsaturated cluster anion [Re₃(μ-H)₄(CO)₁₀]⁻ with tertiary phosphines at room temperature results in the substitution of two hydride ligands (eliminated as H₂) by two PR₃ ligands, leading to saturated [Re₃(μ-H)₂(CO)₁₀-(PR₃)₂]⁻ compounds. A single crystal X-ray diffraction study of the PPh₃ derivative revealed that the two phosphines occupy non-equivalent equatorial coordination sites on the triangular cluster. The rate of the reaction greatly increases with increase of the basicity of the phosphine.     

Synthesis of Platinum-Triruthenium Clusters Using the Zero-Valent Platinum Reagent Pt(nb)3: X-Ray Crystal Structures of Ru3Pt(CO)11(P-iPr3)2, Ru3Pt(μ-H)(μ3-η3-MeCCHCMe)(CO)9(P-iPr3), Ru3Pt(μ3-η2-PhCCPh)(CO)10(P-iPr3), Ru3Pt(μ-H)(μ4-N)(CO)10(P-iPr3) and Ru3Pt(μ-H)(μ4-η2-NO)(CO)10(P-iPr3)

The complexes Pt(nb)_3-n(P-iPr₃)_n (n=1, 2, nb=bicyclo[2.2.1]hept-2-ene), prepared in situ from Pt(nb)₃, are useful reagents for addition of Pt(P-iPr₃)_n fragments to saturated triruthenium clusters. The complexes Ru₃Pt(CO)₁₁(P-iPr₃)₂ (1), Ru₃Pt(-H)(₃-³-MeCCHCMe)(CO)₉(P-iPr₃) (2), Ru₃Pt(₃-²-PhCCPh)(CO)₁₀(P-iPr₃) (3), Ru₃Pt(-H)(₄-N)(CO)₁₀(P-iPr₃) (4) and Ru₃Pt(-H)(₄-²-NO)(CO)₁₀(P-iPr₃) (5) have been prepared in this fashion. All complexes have been characterized spectroscopically and by single crystal X-ray determinations. Clusters 1–3 all have 60 cluster valence electrons (CVE) but exhibit differing metal skeletal geometries. Cluster 1 exhibits a planar-rhomboidal metal skeleton with 5 metal–metal bonds and with minor disorder in the metal atoms. Cluster 2 has a distorted tetrahedral metal arrangement, while cluster 3 has a butterfly framework (butterfly angle=118.93(2)°). Clusters 4 and 5 posseses 62 CVE and spiked triangular metal frameworks. Cluster 4 contains a ₄-nitrido ligand, while cluster 5 has a highly unusual ₄-²-nitrosyl ligand with a very long nitrosyl N–O distance of 1.366(5) Å.     

Synthesis and protonation of an OS3(μ-H)(CO)10(μ-σ,η2-C≡CCMe2OMe) cluster

Triosmium cluster Os₃(-H)(CO)₁₀(--²-CCC Me₂OMe) (1) was obtained by treating OS₃(-H)(-Cl)(CO)₁₀ with LiCCCMe₂OMe. The reaction of cluster1 with HBF₄ · Et₂O at –60 °C leads to the cationic complex [Os₃(-H)(CO)₁₀(-,,²-C=C=C Me₂)]⁺BF₄ ^– (2) with an allenylidene ligand. The^s1H and¹³C NMR spectra of complex2 reveal the temperature dependence caused by migration of hydrocarbon and carbonyl ligands. Thermodynamic parameters were obtained for be exchange process of the allenylidene ligand.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp, 2990–2992, December, 1996.     

Protonation of (μ-H)3Ru3(μ3-CR)(CO)9. Evidence for the formation of an agostic metalhydrogencarbon bond

Protonation of (μ-H)₃M₃(μ₃-CR)(CO)₉ (M = Ru, R = Et or M = Os, R = Me) by dissolution in HSO₃CF₃ yields H₃M₃(HCR)(CO)₉⁺, containing a MHC bridge. The products were characterized by ¹H and ¹³C NMR spectroscopy. Decompositions of other protonated methylidyne clusters from CH₃R and a variety of metal-containing products.     

Cluster chemistry: XXXXVIII. Some reactions of Ru3(CO)12 with nitrogen heterocycles. X-ray crystal structures of Ru3(μ-CO)2(CO)8(bipy) and Ru3(μ-H){μ-N2C3H(CF3)2-3,5}(CO)10

Reactions between Ru₃(CO)₁₂ and the nitrogen heterocycles pyridine, 2,2′-bi-pyridyl, pyrazole, 3,5-dimethylpyrazole and 3,5-bis(trifluoromethyl)pyrazole are described. Pyridine afforded the cyclometallated complex Ru₃(μ-H)(μ-NC₅H₄)(CO)₁₀, which with excess pyridine formed Ru₃(μ-H)₂(μ-NC₅H₄)₂(CO)₈. 2,2′-Bipyridyl gave purple Ru₃(μ-CO)₂(CO)₈(bipy), shown by an X-ray structure to have an Fe₃(CO)₁₂-type structure, with the bipy chelating one of the CO-bridged Ru atoms. The pyrazoles gave Ru₃(μ-H)(μ-N₂CP₃HR₂)(CO)₁₀ (R = H, Me or CF₃), in which the pyrazolide ligand spans an RuRu bond also bridged by H, as shown by the X-ray structure of the CF₃ derivative. The bipyridyl and pyrazole complexes both crystallise in the monoclinic system, the former in space group P2₁/n with unit cell dimensions a 7.834(2), b 25.818(2), c 11.717(1) Å, β 107.41(1)° with Z = 4 and the latter in space group P2₁/c, unit cell dimensions a 16.802(3), b 7.726(1), c 18.807(3) Å, β 114.24(1)° with Z = 4. The structures were refined by conventional least-squares methods with the use of 3336 (2993 for the pyrazole structure) reflections with I > 2.5σ(I) to final R = 0.031 and R_w = 0.034 (0.025 and 0.026).     

1,2-γ3 Azaphosphinine by flash vacuum thermolysis.

1,2-γ³ Azaphosphinine 4 is prepared for the first time by flash vacuum thermolysis of 1-tert.octyl 2-phenyl 1,2-dihydro 1,2-γ³ azaphosphinine. The reaction of 4 with water gives the 1,2-dihydro 1,2-γ5 azaphosphinine 2-oxide.     

Probing the aromaticity of the [(H(t)Ac)3(μ2-H)6], [(H(t)Th)3(μ2-H)6],(+), and [(H(t)Pa)3(μ2-H)6] clusters

In this study we report about the aromaticity of the prototypical [(H(t)Ac)(3)(μ(2)-H)(6)], [(H(t)Th)(3)(μ(2)-H)(6)](+), and [(H(t)Pa)(3)(μ(2)-H)(6)] clusters via two magnetic criteria: nucleus-independent chemical shifts (NICS) and the magnetically induced current density. All-electron density functional theory calculations were carried out using the two-component zeroth-order regular approach and the four-component Dirac-Coulomb Hamiltonian, including scalar and spin-orbit relativistic effects. Four-component current density maps and the integration of induced ring-current susceptibilities clearly show that the clusters [(H(t)Ac)(3)(μ(2)-H)(6)] and [(H(t)Th)(3)(μ(2)-H)(6)](+) are non-aromatic whereas [(H(t)Pa)(3)(μ(2)-H)(6)] is anti-aromatic. However, for the thorium cluster we find a discrepancy between the current density plots and the classification through the NICS index. Our results also demonstrate the increasing influence of f orbitals, on bonding and magnetic properties, with increasing atomic number in these clusters. We think that the enhanced electron mobility in [(H(t)Pa)(3)(μ(2)-H)(6)] is due the significant 5f character of its valence shell. Also the participation of f orbitals in bonding is the reason why the protactinium cluster has the shortest bond lengths of the three clusters. This study provides another example showing that the magnetically induced current density approach can give more reliable results than the NICS index.     

Reaction of the heteronuclear cluster RuOs3(μ-H)2(CO)13 with azulenes

Reaction of the heteronuclear cluster RuOs₃(μ-H)₂(CO)₁₃ (1) with azulene under thermal activation afforded the novel clusters RuOs₃(μ-H)(CO)₉(μ₃,η⁵:η²:η²-C₁₀H₉) (3) and Ru₂Os₃(μ-H)₂(CO)₁₃(μ-CO)(μ₃,η⁵:σ²-C₁₀H₈) (5a), with 4,6,8-trimethylazulene to give RuOs₃(μ-H)(CO)₈(μ-CO)(μ,η⁵:η⁴-C₁₀H₆Me₃) (4) and Ru₂Os₃(μ-H)₂(CO)₁₃(μ-CO)(μ₃,η⁵:σ²-C₁₀H₅Me₃) (5b), and with guaiazulene to give Ru₂Os₃(CO)₁₁(μ₃,η⁵:η³:η³-C₁₀H₅Me₂ⁱPr) (6), respectively. In 3–5, cluster-to-ligand hydrogen transfer appears to have taken place, with the organic moiety capping a trimetallic face in 3, bridging a metal–metal bond in 4 and via a μ₃,η⁵:σ² bonding mode in 5a and 5b. Cluster 6 contains a trigonal bipyramidal metal framework with the guaiazulene ligand over a triangular metal face. All five clusters have been completely characterised, including by single-crystal X-ray diffraction analysis.     

Darstellung von Derivaten des 1,2-Äthylendioxybenzols, 2. Mitt.

Zusammenfassung Es wird die Chlormethylierung von Äthylendioxybenzol und die Umwandlung der Bis-chlormethylderivate in das entsprechende Diol, den Dialdehyd und die Dicarbonsäure beschrieben.1. Mitt.:M. Lipp, F. Dallacker undR. Schaffranek, Chem. Ber.91, 2247 (1958).     

Synthesis and ligand substituion chemistry of dinuclear,phosphido-bridged complexes of manganese. X-ray crystal structures of Mn2(μ-H)(μ-Cy2P)(CO)7(PCy2H)(1) and Mn2(μ-H)(μ-Cy2P)(CO)6(PMe32

Reaction of Mn₂ (CO)₁₀ with two equivalents of dicyclohexylphosphine in toluene at 110° produces Mn₂ (μ-H)(μ-Cy₂P)(CO)₇(PCy₂H) (1) in 60% yield. Interaction of 1 with excess trimethylphosphine produces Mn₂(μ-H)(μ-Cy₂P)(CO)₆ (PMe₃)(₂ (2) in 90% yield. The X-ray crystal structures of 1 and 2 have been determined. Both structures contain two Mn atoms bridged by a Cy₂P group and a hydridge. In each case, the metal atoms exhibit distorted octahedral geometry, with the phosphines occupying positions trans to the P atom of the bridging dicyclohexylphosphine. A metal-metal distance of ca. 2.9 Å separates the manganese atoms in both complexes.     

Synthesis and properties of furan derivatives. 3. Synthesis of 1,2-disubstituted δ2-imidazolines containing furfuryl and tetrahydrofurfuryl groups

The condensation of N-furfuryl- and N-tetrahydrofurfurylethylenediamines with hydrochloride salts of iminoesters of carboxylic acids gives 1,2-disubstituted ²-imidazolines containing furfuryl or tetrahydrofurfuryl groups at N¹.For communication 2, see [1]Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1312–1315, October, 1992.