Synthesis of Palladium Clusters with the P--N--P Assembling Ligands (Ph2P)2CH2 (dppm) and (Ph2P)2NH (dppa). Crystal Structure of [Pd4(μ-Cl)2(μ-dppm)2(μ-dppa)2](PF6)2

Tetrapalladium clusters containing dppa or dppa and dppm bridging ligands were prepared by condensation of dinuclear units. Reaction of [Pd₂Cl₂(-dppa)₂] with [Cu(PPh₃)]PF₆ (generated in situ in THF) yielded [Pd₄(-Cl)₂(-dppa)₄] (PF₆)₂ (4) in a virtually quantitative yield but [Pd₄(-Cl)₂(-dppm)₂(-dppa)₂] (PF₆)₂ (6) was best prepared in CH₂Cl₂ from [Pd₂Cl₂(-dppm)₂] and [Pd₂(MeCN)₂(-dppa)₂](PF₆)₂ (2). The structure of 6·2(CH₃)₂CO·2H₂O was determined by X-ray diffraction. It consists of a planar, centrosymmetric 10-membered ring structure. The four bridging diphosphine ligands are of two types: two dppa ligands support the Pd Pd bonds [2.6055(4) Å], whereas the two dppm ligands bridge between two palladium atoms separated by 3.722(4) Å, which are also bridged by a chloride ligand.     

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.     

A New Preparation of Mo2(CO)8(μ-PPh2)2 and W2(CO)8(μ-PPh2)2 by a Phosphorus-Carbon Bond Cleavage Reaction. Crystal Structure of a New Polymorph of Mo2(CO)8(μ-PPh2)2

A new synthesis of Mo₂(CO)₈(-PPh₂)₂ and W₂(CO)₈(-PPh₂)₂ by the reaction of molybdenum and tungsten hexacarbonyls with a tetraazamacrocyclic ligand containing —CH₂PPh₂ side chains, comprising cleavage of the phosphorus-methylene bond has been performed. The complexes have been investigated by magnetic and spectroscopic measurements and by single-crystal structure analyses. The structural characterization of a new polymorph of Mo₂(CO)₈(-PPh₂)₂ has been described.     

Synthesis and characterisation of novel selenium-containing clusters; crystal structures of [Ru4(μ4-Se)2(CO)8(μ-CO)3] and [Ru3(μ3-Se)2(CO)7(Ph2P(CH2)3PPh2)]

The compound [Ru₄(μ-Se)₂(CO)₈(μ3-CO)₃] (1), has been obtained in good yield by vacuum pyrolysis of [RU₃(CO)₁₂] with [Ph₂Se₂] at 185°C. Reaction of 1 with 1,3-bis(diphenylphosphino)propane at room temperature affords the novel cluster [RU₃(μ₃-Se)₂(CO)₇(Ph₂P(CH₂)₃PPh₂)] (2). The structures of 1 and 2 have been determined by an X-ray diffraction study.     

Formation of mixed-metal alkoxides mediated by the reactivity of coordinated pinacol: Synthesis and molecular structures of Ce2Ti2(μ3-O)2(μ,η2-OCMe2CMe2O)4(OPri)4(PriOH)2 and of Ce2Nb2(μ3-O)2(μ,η2-OCMe2CMe2O)4(OPri)6

The addition of pinacol to mixtures of titanium and cerium isopropoxides as well as the use of insoluble titanium and cerium pinacolate synthons was investigated as a route to M-Ce (M=Ti, Nb) species. Pinacol was able to promote the formation of mixed-metal species and the first Ce-Ti and Ce-Nb species namely Ce_2Ti(pin)₂(OPrⁱ)₈ and [M₂Ce₂(μ₃-O)₂(μ,η²pin)₄(OPrⁱ)₆H_x] [M=Ti, x=2; M=Nb, x=0; pin=OCMe₂-COMe₂] were isolated and characterized by FT-IR and ¹H NMR. The latter were also characterized by X-Ray diffraction. Their structures are based on a rhombus compressed along the M⋯M direction with 6-coordinated metals. The pinacolate moieties act as bridging-chelating ligands. The metal–oxygen bond lengths vary according to M–O(pin)<M-μ₃–O<Mμ–O(pin)<Ce–OPrⁱ<Ce–μ₃O.     

Syntheses and characterization of the vanadium trimer (V3(μ3-O)O2)(μ2-O2P(CH2C6H5)2)6(4,4′-bipyridine) and the vanadium hexamer [(V3(μ3-O)O2)(μ2-O2P(CH2C6H5)2)6]2(μ2-N1,N2-di(pyridin-4-yl)oxalamide)

Reacting VO(acac)₂ with six equivalents of dibenzylphosphinic acid in the presence of 4,4′-bipyridine or μ₂-N¹,N²-di(pyridin-4-yl)oxalamide leads to trimeric (V₃(μ₃-O)O₂)(μ₂-O₂P(CH₂C₆H₅)₂)₆(4,4′-bipyridine) or the hexamer [(V₃(μ₃-O)O₂)(μ₂-O₂P(CH₂C₆H₅)₂)₆]₂(μ₂-N¹,N²-di(pyridin-4-yl)oxalamide). The complexes were characterized by spectroscopic (FTIR and ¹H NMR spectroscopies), TGA, and by single crystal X-ray diffraction measurements. The structures consist of a planar central core where three vanadium ions are arranged in the form of a quasi-isosceles triangle and contain an interstitial O which is multiply bonded to one V and weakly interacting at different bond distances to the remaining two V ions.     

Synthesis and structures of complexes Os3(μ-H)2(CO)7(μ-RC5H3N){μ3-Ph2PCH2P(C6H4)Ph} (R = H, Me) with ortho-metalated pyridine ligands. The revised structure of the triosmium cluster ”Os3(μ-H)2(CO)7(μ-C6H4){μ3-Ph2PCH2P(C6H4)Ph}”

The structure of the previously synthesized triosmium cluster was revised. The structure Os₃(μ-H)₂(CO)₇(μ-C₆H₄){μ₃-Ph₂PCH₂P(C₆H₄)Ph} suggested earlier was not confirmed. The cluster has the composition Os₃(μ-H)₂(CO)₇(μ-C₅H₄N){μ₃-Ph₂PCH₂P(C₆H₄)Ph} and contains the ortho-metalated pyridine ligand. The X-ray diffraction study of the complex Os₃(μ-H)₂(CO)₇(μ-MeC₅H₃N){μ₃-Ph₂PCH₂P(C₆H₄)Ph} containing the ortho-metalated 4-methylpyridine ligand made it possible to distinguish between the C and N atoms of the pyridine ligands in the resulting triosmium clusters.     

Electrochemical oxidative addition of chloride to Rh2(μ-dppm)2(CO)2Cl2

The electrochemical oxidation of trans-Rh₂(μ-dppm)₂(CO)₂Cl₂ (dppm = bis (diphenylphosphino)methane) in the presence of chloride has afforded the new dirhodium(II) unsymmetrical complex Rh₂(μ-dppm)₂(μ-Cl)(CO)Cl₃ which is readily converted to the complex [Rh₂(μ-dppm)₂(μ-Co)(μ-Cl)Cl₂]PF₆. This species has been shown to undergo addition reactions with chloride to regenerate [Rh₂(μ-dppm)₂(μ-Cl)Cl₃(CO)], and with carbon monoxide and t-butylisocyanide to give the additional new dirhodium(II) complexes [Rh₂(μ-dppm)₂(μ-Cl)Cl₂(CO)₂]PF₆ and [Rh₂(μ-dppm)₂(μ-Cl)(CNC(CH₃)₃)₂Cl₂]PF₆, respectively. During prolonged exposure to carbon monoxide [Rh₂(μ-dppm)₂(μ-Co)(μ-Cl)Cl₂]PF₆ undergoes reduction with the loss of chloride to give [Rh₂(μ-dppm)₂(μ-Cl)(CO)₂]PF₆.     

铁磷硫簇合物(μ-Me_2P)(μ-t-Bus)Fe_2(CO)_6的单晶分子结构

铁磷硫簇合物(μ-R_2P)(μ-RS)Fe_2(CO)_6是一种混合配体桥连的羰基铁配合物,它既可以看作是铁磷簇合物(μ-R_2P)_2Fe_2(CO)_6的     

Synthesis of [Ru4(μ3-η2-CO)(CO)9{μ-(RO)2PN(Et)P(OR)2}2] (R = Me or Pri): Butterfly clusters of ruthenium containing a triply bridging carbonyl ligand with an unusual mode of coordination. Crystal structure of [Ru4(μ3-η2-CO)(CO)9{μ-(MeO)2PN(Et)P(OMe)2}2]

Reaction of [Ru₃(CO)₁₂] with a two molar proportion of (RO)₂PN(Et)P(OR)₂ (R = Me or Prⁱ) in benzene under reflux affords a number of products including [Ru₃(CO)₁₀{μ-(RO)₂PN(Et)P(OR)₂}], [Ru₃(CO)₉{μ-(RO)₂PN(Et)P(OR)₂}{η¹-(RO)₂PN(Et)P(OR)₂}] and, as the major species, the tetranuclear derivative [Ru₄(μ₃-η²-CO)(CO)₉{μ-(RO)₂PN(Et)P(OR)₂}₂]. An X-ray diffraction study of [Ru₄(μ₃-η²-CO)(CO)₉{μ-(MeO)₂PN(Et)P(OMe)₂}₂] has revealed that the skeletal framework adopts a butterfly structure and that one of the carbonyl groups functions as a triply bridging four-electron donor ligand capping the two wing-tip and one of the hinge ruthenium atoms.     

Synthesis, Structure and Properties of a Copper Complex Cu2(μ-PhCOO)2(μ-CH3COO)2(CH3OH)2

The title complex Cu2(μ-PhCOO)2(μ-CH3COO)2(CH3OH)2 1(C20H24Cu2O10, Mr=structure was determined by X-ray diffraction method. Complex 1 belongs to orthorhombic, space group Pbca with a = 13.083(6), b = 8.078(4), c = 21.566(2)(A), V = 2279(2) (A)3, Z = 4, Dc= 1.607g/cm3, F(000) = 1128,μ(MoKa) = 1.918 mm-1, the final R = 0.0506 and wR = 0.1382. Each Cu(Ⅱ)ion is coordinated by five oxygen atoms from two benzoic acids, two acetic acids and one methanol molecule in a slightly distorted square pyramidal environment. The title molecules construct a 2-D complex 1 displays strong emissions. IR and TG-DTA studies are also presented.     

CRYSTAL STRUCTURE OF Mo_3(μ3-S)_2(μ-Cl)_3[S_2P(OEt)_2]_3

<正> M=1013.98, hexagonal, P63/m, a=b=15.492(2), c=8.530(4)A, γ=120°, V=1773A3, Z=2, Dc=1.899°g.cm-3. Final R=0.042 for 611 reflections.This is a Bl(bicapped) type trinuclear molybdenum cluster with two S capping atoms located on the 63 axis and exhibits full D3h symmetry. The Mo-Mo distances are 2.606(1)A, with a bond order of 11/3. It is paramagnetic.     

Synthesis and Structure of a Novel Mg6 Cluster Molecule Mg6(μ3-OH)2(μ3-Br)2(μ-Br)8(THF)8

A novel Mg₆ cluster molecule with the formula of Mg₆( ₃-OH)₂( ₃-Br)₂(-Br)₈(THF)₈ (1) has been isolated in 38% yield from a reaction of the Grignard reagent, 2-naphthyl-Mg-Br with BBr₃ in THF. The structure of 1, determined by a single-crystal X-ray diffraction analysis, contains two Mg₃ triangles linked together by two bridging bromide ligands. Within each Mg₃ triangle, one hydroxide and one bromide ligand function as triply bridging ligands capping both sides of the Mg₃ triangle. The coordination geometry around each Mg(II) ion is approximately octahedral. NMR studies revealed that compound 1 is highly fluxional in solution.     

Reactivity of the bridged-sulfide complex Pd2Cl2(μ-S)(μ-dmpm)2 toward electrophiles

The dipalladium(I) complex Pd(2)Cl(2)(dmpm)(2) (1a) [dmpm = bis(dimethylphosphino)methane] is known to react with elemental sulfur (S(8)) to give the bridged-sulfide complex Pd(2)Cl(2)(μ-S)(dmpm)(2) (2a) but, in the presence of excess S(8), PdCl(2)[P,S-dmpm(S)] (4a) and dmpm(S)(2) are generated. Treatment of 1a with elemental selenium (Se(8)), however, gives only Pd(2)Cl(2)(μ-Se)(dmpm)(2) (3a). Complex 4a is best made by reaction of trans-PdCl(2)(PhCN)(2) with dmpm(S). Complex 2a reacts with MeI to yield initially Pd(2)I(2)(μ-S)(dmpm)(2) and MeCl, and then Pd(2)I(2)(μ-I)(2)(dmpm)(2) and Me(2)S, whereas alkylation of 2a with MeOTf generates the cationic, bridged-methanethiolato complex [Pd(2)Cl(2)(μ-SMe)(dmpm)(2)]OTf (5). Oxidation of 2a with m-CPBA forms a mixture of Pd(2)Cl(2)(μ-SO)(dmpm)(2) and Pd(2)Cl(2)(μ-SO(2))(dmpm)(2), whereas Pd(2)Br(2)(μ-S)(dmpm)(2) reacts selectively to give Pd(2)Br(2)(μ-SO)(dmpm)(2) (6b). Treatment of the Pd(2)X(2)(μ-S)(dmpm)(2) complexes with X(2) (X = halogen) removes the bridged-sulfide as S(8), with co-production of Pd(II)(dmpm)-halide species. X-ray structures of 3a, 5 and 6b are presented. Reactions of dmpm with S(8) and Se(8) are clarified. Differences in the chemistry of the dmpm systems with that of the corresponding dppm systems [dppm = bis(diphenylphosphino)methane] are discussed.