- ?-Arene clusters of cobalt and ruthenium on the base of biphenyl
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For the first time monocluster ?-arene derivatives of biphenyl Ph2Co4(CO)9 and Ph2Ru6C(CO)14, the shared mononuclear monocluster complex Ph2Cr(CO)3Co4(CO)9, and the bicluster derivative of cobalt Ph22 have been synthesized.IR and 1H NMR spectra
- Kaganovich, V. S.,Kerzina, Z. A.,Rybinskay, M. I.
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- (η6-Biphenyl)tricarbonylchromium and μ- (η6:η6)-biphenyl-bis(tricarbonylchromium)
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The structural features of (η-Biphenyl)tricarbonylchromium and μ-(η6:η6)-biphenyl-bis(tricarbonylchromium was investigated using density functional theory and natural bonding orbital theory analyses. It was found that the compund has a typical piano-stool coordination about the Cr center and the dihedral angle betwwen the planes of the phenyl rings is 23.55 (5)°. It was also found that the corresponding angle in compound is 0° because the molecule occupies a crystallographic inversion center. The Cr atoms reside on opposite sides of the biphenyl ligand.
- Guzei, Ilia A.,Czerwinski, Curtis J.
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p. m615-m617
(2007/10/03)
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- Palladium catalysed cross-coupling of (fluoroarene)tricarbonyl-chromium(o) complexes
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(Fluoroarene)tricarbonylchromium(o) complexes were found to undergo Suzuki and Stille cross-coupling reactions to form functionalised biaryl and styrene complexes in up to 87 and 52% yields, respectively. The Suzuki reactions were optimal with dipalladium tris(dibenzylideneacetone)-trimethylphosphine-caesium carbonate in DME at reflux. The Stille reactions were optimal with dipalladium tris(dibenzylideneacetone)-trimethylphosphine-caesium fluoride in DME at reflux and neither was adversely affected by a methoxy group on the complexed ring. The Suzuki reaction tolerated a chloro group on the arylboronic acid ring but not a bromo group. The Royal Society of Chemistry 2000.
- Wilhelm, Rene,Widdowson, David A.
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p. 3808 - 3813
(2007/10/03)
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- Palladium catalysed cross-coupling of (fluoroarene)tricarbonylchromium(0) complexes
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Fluoroarenetricarbonylchromium(0) complexes were found to undergo Suzuki reactions with arylboronic acids to form biaryltricarbonylchromium(0) complexes in the presence of trimethylphosphine/palladium dibenzylideneacetone and caesium carbonate or caesium
- Widdowson, David A.,Wilhelm, Rene
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p. 2211 - 2212
(2007/10/03)
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- Electrophilic Substitution in (Arene)tricarbonylchromium Complexes. Part 1.
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The Friedel-Crafts acetylation of several (arene)tricarbonylchromium complexes have been investigated.From the results it is concluded that the tricarbonylchromium group deactivates to a small extent towards electrophilic substitution the ring to which it is attached.In the case of tricarbonyl(diphenylmethane)chromium (1; n=1), however, attack occurred on both rings to about an equal extent, possible explanations for this unexpected behaviour are advanced.
- von Rosenberg, Joseph L.,Pinder, A. Reginald
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p. 747 - 752
(2007/10/02)
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- Synthetic Applications of Lithiated Tricarbonyl-η6-arenechromium(0) Complexes: Copper and Palladium Catalysed Substitutions
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Regioselectively lithiated tricarbonyl-η6-arenechromium(0) complexes can be acylated and allylated in high yield via the analogous arylcopper dimethyl sulphide complexes, and vinylated and arylated via palladium catalysed cross coupling of the
- Beswick, Paul J.,Leach, Susan J.,Masters, Nigel F.,Widdowson, David A.
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- REDUCTIVE ELIMINATION OF DIHYDROGEN FROM ARENECHROMIUM DIMERS
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Biphenylbis(chromium dicarbonyl)-μ-bis(diphenylphosphido)methane and its arsenic analog have been prepared in good yield by UV irradiation of biphenylbis(chromium tricarbonyl) and bis(diphenylphosphido)methane or bis(diphenylarsino)methane in benzene.Addition of strong acid to these dinuclear compounds results in rapid dihydrogen evolution and subsequent decomposition of the oxidized chromium species.A scheme for the dihydrogen elimination reaction is proposed in which both metal centers are protonated in an oxidative addition step, followed by reductive elimination of dihydrogen from the two metal centers.
- Bitterwolf, Thomas E.
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p. 305 - 316
(2007/10/02)
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- Electrochemical generation of stable cations of (arene)tricarbonyichromium complexes. Studies on thenoninteraction of the tricarbonyichromium groups in bis and tris complexes
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Complexes of the type (CH3)2Sn[ArCr(CO)3]2 were studied by cyclic voltammetry. The compounds can be made to undergo chemically reversible oxidation upon judicious choice of conditions and modification of Ar. The persistence of the cations seems to be a function of the steric bulk around the phenyl rings. Oxidation involves one electron per tricarbonylchromium group. The tricarbonylchromium moieties are essentially noninteracting and therefore adhere to the Bard-Anson-Saveant model. The same results are found for the bis and tris complexes of methyltriphenyltin where a dication and trication are formed, respectively. The structure of (CH3)2Sn[2,4,6-(CH3)3C 6H2Cr(CO)3]2 was determined from 5287 observed diffractometer data and refined to an R value of 4.4%. The compound crystallizes in space group P2l/c with Z = 4 and lattice constants of a = 15.514 (2) ?, b = 13.026 (2) ?, c = 15.709 (2) ?, and β= 119.51 (1)°. The structure consists of a tin atom that is bonded to two methyl and two mesityl groups in a distorted tetrahedral geometry. Each mesityl group is also bonded to a Cr(CO)3 moiety in a η6 fashion. The average Sn-C(methyl) and Sn-C(mesityl) distances are 2.149 (4) and 2.182 (3) ?, respectively. When the Cr-CO bonds are projected onto the mesityl plane, they eclipse the methyl-substituted ring carbon atoms.
- Rieke, Reuben D.,Tucker, Indu,Milligan, Stuart N.,Wright, Dennis R.,Willeford, Bennett R.,Radonovich, Lewis J.,Eyring
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p. 938 - 950
(2008/10/08)
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