Syntheses,reactivity, and crystal structures of molybdenum complexes with pyridine-2-thionate (pyS)-containing ligands: crystal structures of [Mo(eta(3)-C(3)H(5))(CO)(2)](2)(mu-eta(1),eta(2)-pyS)(2), exo-[Mo(eta(3)-C(3)H(5))(CO)(eta(2)-pyS)(eta(2)-dppe)], [Mo(CO)(3)(eta(1)-SC(5)H(4)NH)(eta(2)-dppm)], and [Mo(CO)(eta(2)-pyS)(2)(eta(2)-dppm)

The doubly bridged pyridine-2-thionate (pyS) dimolybdenum complex [Mo(eta(3)-C(3)H(5))(CO)(2)](2)(mu-eta(1),eta(2)-pyS)(2) (1) is accessible by the reaction of [Mo(eta(3)-C(3)H(5))(CO)(2)(CH(3)CN)(2)Br] with pySK in methanol at room temperature. Complex 1 reacts with piperidine in acetonitrile to give the complex [Mo(eta(3)-C(3)H(5))(CO)(2)(eta(2)-pyS)(C(5)H(10)NH)] (2). Treatment of 1 with 1,10-phenanthroline (phen) results in the formation of complex [Mo(eta(3)-C(3)H(5))(CO)(2)(eta(1)-pyS)(phen)] (3), in which the pyS ligand is coordinated to Mo through the sulfur atom. Four conformational isomers, endo,exo-complexes [Mo(eta(3)-C(3)H(5))(CO)(eta(2)-pyS)(eta(2)-diphos)] (diphos = dppm, 4a-4d; dppe, 5a-5d), are accessible by the reactions of 1 with dppm and dppe in refluxing acetonitrile. Homonuclear shift-correlated 2-D (31)P((1)H)-(31)P((1)H) NMR experiments of the mixtures 4a-4d have been employed to elucidate the four stereoisomers. The reaction of 4 and pySK or [Mo(CO)(3)(eta(1)-SC(5)H(4)NH)(eta(2)-dppm)] (6) and O(2) affords allyl-displaced seven-coordinate bis(pyridine-2-thionate) complex [Mo(CO)(eta(2)-pyS)(2)(eta(2)-dppm)] (7). All of the complexes are identified by spectroscopic methods, and complexes 1, 5d, 6, and 7 are determined by single-crystal X-ray diffraction. Complexes 1 and 5d crystallize in the orthorhombic space groups Pbcn and Pbca with Z = 4 and 8, respectively, whereas 6 belongs to the monoclinic space group C2/c with Z = 8 and 7 belongs to the triclinic space group Ponemacr; with Z = 2. The cell dimensions are as follows: for 1, a = 8.3128(1) A, b = 16.1704(2) A, c = 16.6140(2) A; for 5d, a = 17.8309(10) A, b = 17.3324(10) A, c = 20.3716(11) A; for 6, a = 18.618(4) A, b = 16.062(2) A, c = 27.456(6) A, beta = 96.31(3) degrees; for 7, a = 9.1660(2) A, b = 12.0854(3) A, c = 15.9478(4) A, alpha = 78.4811(10) degrees, beta = 80.3894(10) degrees, gamma = 68.7089(11) degrees.     

Reaction of nido-7,8-C(2)B(9)H(13) with Dicobalt Octacarbonyl: Crystal Structures of the Complexes [Co(2)(CO)(2)(eta(5)-7,8-C(2)B(9)H(11))(2)], [Co(2)(CO)(PMe(2)Ph)(eta(5)-7,8-C(2)B(9)H(11))(2)], and [CoCl(PMe(2)Ph)(2)(eta(5)-7,8-C(2)B(9)H(11))

The compounds [Co(2)(CO)(8)] and nido-7,8-C(2)B(9)H(13) react in CH(2)Cl(2) to give a complex mixture of products consisting primarily of two isomers of the dicobalt species [Co(2)(CO)(2)(eta(5)-7,8-C(2)B(9)H(11))(2)] (1), together with small amounts of a mononuclear cobalt compound [Co(CO)(2)(eta(5)-10-CO-7,8-C(2)B(9)H(10))] (5) and a charge-compensated carborane nido-9-CO-7,8-C(2)B(9)H(11) (6). In solution, isomers 1a and 1b slowly equilibrate. However, column chromatography allows a clean separation of 1a from the mixture, and a single-crystal X-ray diffraction study revealed that each metal atom is ligated by a terminal CO molecule and in a pentahapto manner by a nido-C(2)B(9)H(11) cage framework. The two Co(CO)(eta(5)-7,8-C(2)B(9)H(11)) units are linked by a Co-Co bond [2.503(2) ?], which is supported by two three-center two-electron B-H right harpoon-up Co bonds. The latter employ B-H vertices in each cage which lie in alpha-sites with respect to the carbons in the CCBBB rings bonded to cobalt. Addition of PMe(2)Ph to a CH(2)Cl(2) solution of a mixture of the isomers 1, enriched in 1b, gave isomers of formulation [Co(2)(CO)(PMe(2)Ph)(eta(5)-7,8-C(2)B(9)H(11))(2)] (2). Crystals of one isomer were suitable for X-ray diffraction. The molecule 2a has a structure similar to that of 1a but differs in that whereas one B-H right harpoon-up Co bridge involves a boron atom in an alpha-site of a CCBBB ring coordinated to cobalt, the other uses a boron atom in the beta-site. Reaction between 1b and an excess of PMe(2)Ph in CH(2)Cl(2) gave the complex [CoCl(PMe(2)Ph)(2)(eta(5)-7,8-C(2)B(9)H(11))] (3), the structure of which was established by X-ray diffraction. Experiments indicated that 3 was formed through a paramagnetic Co(II) species of formulation [Co(PMe(2)Ph)(2)(eta(5)-7,8-C(2)B(9)H(11))]. Addition of 2 molar equiv of CNBu(t) to solutions of either 1a or 1b gave a mixture of two isomers of the complex [Co(2)(CNBu(t))(2)(eta(5)-7,8-C(2)B(9)H(11))(2)] (4). NMR data for the new compounds are reported and discussed.     

Supramolecular gas-solid reaction between formic acid vapours and solid [CoIII(eta 5-C5H4COOH)(eta 5-C5H4COO)

Exposure of the solid zwitterion [CoIII(eta 5-C5H4COOH)(eta 5-C5H4COO)] to vapours of formic acid quantitatively produces the co-crystal [CoIII(eta 5-C5H4COOH)(eta 5-C5H4COO)] [HCOOH] without proton transfer from formic acid to the deprotonated -COO- group on the zwitterion; formic acid can be quantitatively removed by mild thermal treatment, regenerating the starting material.     

Condensed metallaborane clusters: synthesis and structure of Fe2(CO)6(eta5-C5Me5RuCO)(eta5-C5Me5Ru)B6H10

Mild pyrolysis of (eta5-C5Me5Ru)2B6H12 with Fe2(CO)9 yields the 12 skeletal electron pair (sep) Fe2(CO)6(eta5-C5Me5RuCO)(eta5-C5Me5Ru)B6H10 cluster; the title compound represents a novel class of hybrid multiple cluster in which a Fe2B2 tetrahedron has been fused to a ruthenaborane substrate.     

Synthesis and structural characterization of Be(eta 5-C5Me5)(eta 1-C5Me4H). Evidence for ring-inversion leading to Be(eta 5-C5Me4H)(eta 1-C5Me5)

The mixed-ring beryllocene Be(C5Me5)(C5Me4H), that contains eta 5-C5Me5 and eta 1-C5Me4H rings, the latter bonded to the metal through the CH carbon atom (X-ray crystal structure) reacts at room temperature with CNXyl (Xyl = C6H3-2,6-Me2) to give an iminoacyl product, Be(eta 5-C5Me4H)[C(NXyl)C5Me5] derived from the inverted beryllocene structure Be (eta 5-C5Me4H)(eta 1-C5Me5).     

Proton induced P-H and Mo-H bond activation at the phosphide bridged dimolybdenum complexes [Mo2Cp2(mu-H)(mu-PHR)(CO)4](R = Cy, 2,4,6-C6H2R'3; R'= H, Me, tBu)

The new hydride complexes [Mo2Cp2(mu-H)(mu-PHR)(CO)4] having bulky substituents (R = 2,4,6-C(6)H2tBu3= Mes*, R = 2,4,6-C6H2Me3= Mes) have been prepared in good yield by addition of Li[PHR] to the triply bonded [Mo2Cp2(CO)4] and further protonation of the resulting anionic phosphide complex [Mo2Cp2(mu-PHR)(CO)4]-. Protonation of the Mes* compound with either [H(OEt2)2][B{3,5-C6H3(CF3)2}4] or HBF4.OEt2 gives the cationic phosphinidene complex [Mo2Cp2(mu-H)(mu-PMes*)(CO)4]+ in high yield. In contrast, protonation of the analogous hydride compounds with Mes or Cy substituents on phosphorus give the corresponding unsaturated tetracarbonyls [Mo2Cp2(mu-PHR)(CO)4]+, which are unstable at room temperature and display a cis geometry. Decomposition of the latter give the electron-precise pentacarbonyls [Mo2Cp2(mu-PHR)(mu-CO)(CO)4]+, also displaying a cis arrangement of the metal fragments. In the presence of BF4- as external anion, fluoride abstraction competes with carbonylation to yield the neutral fluorophosphide hydrides [Mo2Cp2(mu-H)(mu-PFR)(CO)4]. Similar results were obtained in the protonation reactions of the hydride compounds having a Ph substituent on phosphorus. In that case, using HCl as protonation reagent gave the chloro-complex [Mo2ClCp2(mu-PHPh)(CO)4] in good yield. The structures and dynamic behaviour of the new compounds are analyzed on the basis of solution IR and 1H, 31P, 19F and 13C NMR data as well as the X-ray studies carried out on [Mo2Cp2(mu-H)(mu-PHMes)(CO)4](cis isomer), [Mo2Cp2(mu-H)(mu-PFMes)(CO)4](trans isomer), [Mo2Cp2(mu-PHCy)(mu-CO)(CO)4](BF4) and [Mo2ClCp2(mu-PHPh)(CO)4].     

Substituted derivatives of [Fe2(CO)9] and [Ru2(CO)9] and their susceptibility to electrophilic attack: X-ray crystal structure of [Fe2(μ-Br)(CO)4{μ-(C6H5O)2PN(C2H5)P(OC6H5)2}2]PF6

Bis- and, in particular, tetra-substituted ditertiary phosphine and diphosphazane derivatives of [Fe₂(CO)₉] and [Ru₂(CO)₉], readily synthesised by reaction of the appropriate bidentate ligand with [Fe₂(CO)₉] and [Ru₃(CO)₁₂], respectively, are very susceptible to electrophilic attack by reagents such as halogens and protons; the solid state structure of one of the products [Fe₂(μ-Br)(CO)₄ {μ-(PhO)₂PN(Et)P(OPh)₂}₂]PF₆ has been determined by X-ray crystallography.     

X-ray crystal structure of (eta(5)-pentaphenylcyclopentadienyl)[1-(eta(5/6)-phenyl)-2,3,4,5-tetraphenylcyclopentadienyl]iron(II), [Fe(eta(5)-C(5)Ph(5))[(eta(5/6)-C(6)H(5))C(5)Ph(4)]], a linkage isomer of decaphenylferrocene

Very dark blue prismatic crystals of [Fe(eta(5)-C(5)Ph(5))[(eta(5/6)-C(6)H(5))(C(5)Ph(4))]], the linkage isomer of decaphenylferrocene, were grown from (3:1 v/v) hexane/ethyl acetate and characterized by single-crystal X-ray diffraction (space group P2(1)/n, R1(F) 0.0404). The iron atom is coordinated to two C(5)Ph(5) ligands: one with an eta(5)-C(5)-configuration and the other with a coordinated arene configuration. The phenyl groups of the (eta(5)-C(5)Ph(5)) ligand are oriented in a "paddle-wheel" arrangement about the C(5) ring, with which four of them make an average angle of approximately 53 degrees, the other, an angle of approximately 42 degrees. The coordinated C(6)H(5) ring of the other ligand is inclined at only approximately 5 degrees to the uncoordinated C(5) ring, with which three of the other four phenyl rings make an average angle of approximately 64 degrees, and the other (opposite the coordinated arene ring), an angle of 38 degrees.     

Synthesis,Structure and Hydrogenation Property of trans-PdCl_2｛Ph_2P[o-C_6H_4CH(OC_2H_5)_2]｝_2

Ｓｙｎｔｈｅｓｉｓ,ＳｔｒｕｃｔｕｒｅａｎｄＨｙｄｒｏｇｅｎａｔｉｏｎＰｒｏｐｅｒｔｙｏｆｔｒａｎｓ┐ＰｄＣｌ２｛Ｐｈ２Ｐ［ｏ┐Ｃ６Ｈ４ＣＨ（ＯＣ２Ｈ５）２］｝２＊ＸＵＰｉａｎ－ｐｉａｎ,ＧＡＯＪｉｎｇ－ｘｉｎｇ＊＊,ＺＨＯＵＺｈａｏ－ｈｕｉ,ＷＡＮ...     

Use of the Cationic Fragments [Ru(η5-C5H5) (MeCN)3]+ and [M(η6-C6H5R)(MeCN)3]+ (M=Os, Ru; R=H, Me) as Ionic Coupling Reagents in the Synthesis of the Clusters [Os4M2(CO)12(η6-C6H5R)], [Os4M(CO)12(η6-C6H6)(Au2dppm)] and [Os5Ru(CO)15(η5-C5H5)(AuPPh3)]*

The clusters [H₂Os₄M(CO)₁₂eta⁶-C₆H₆)] (M=Os, Ru) may be deprotonated to generate anions [Os₄M(CO)₁₂eta⁶-C₆H₆)]^2- which react with [M′eta⁶-C₆H₅R) (MeCN)₃]²⁺(M^′=Os, Ru; R=H, Me) to give the bicapped tetrahedral clusters [Os₄(CO)₁₂MM′eta⁶-C₆H₅R)₂]. Whereas [Os₄(CO)₁₂M₂eta⁶-C₆H₆)₂] (M=Os, Ru) have one Meta⁶-C₆H₆) unit in a site connected to three other metals, {3}, and one in a site connected to four other metals, {4}, [Os₄(CO)₁₂OsRueta⁶-C₆H₆)₂] has the Rueta⁶-C₆H₆) unit in the {3} site irrespective of whether the Os or Ru anion is capped. Coupling of these anions with Au₂dppm yields [Os₄M(CO)₁₂eta⁶-C₆H₆)(Au₂dppm)] (M=Os, Ru), which have the arene ligand in the axial site of a trigonal bipyramid and the digold unit capping two faces. Reduction of [H₂Os₅(CO)₁₅] with K/Ph₂CO and coupling with [Rueta⁵-C₅H₅)(MeCN)₃]²⁺yields the monoanion [Os₅(CO)₁₅Rueta⁵-C₅H₅)]^? which reacts with [AuPPh₃]⁺ generating [Os₅(CO)₁₅Rueta⁵-C₅H₅)(AuPPh₃)] with the “Ru(C₅H₅)” unit in the terminal {3} site.     

A non-classical hydrogen bond in the molybdenum arene complex [eta 6-C6H5C6H3(Ph)OH]Mo(PMe3)3: evidence that hydrogen bonding facilitates oxidative addition of the O-H bond

Mo(PMe3)6 reacts with 2,6-Ph2C6H3OH to give the eta 6-arene complex [eta 6-C6H5C6H3(Ph)OH]Mo(PMe3)3 which exhibits a non-classical Mo...H-OAr hydrogen bond; DFT calculations indicate that the hydrogen bonding interaction facilitates oxidative addition of the O-H bond to give [eta 6,eta 1-C6H5C6H3(Ph)O]Mo(PMe3)2H.